Green Computing
Harnessing Green
IT: Principles and
Practices
San Murugesan
Adopting a holistic approach to greening IT is our responsibility toward
creating a more sustaining environment.
E
nterprises, governments, and societies at
large have a new important agenda: tackling environmental issues and adopting
environmentally sound practices. Over
the years, the use of IT has exploded in several
areas, improving our lives and work and offering
convenience along with several other benefits.
We are passionate about
advances in and widespread
adoption of IT. However, IT
has been contributing to enGreening Unwanted
vironmental problems, which
Computers: The Three Rs
most people don’t realize.
Computers and other IT inGreen IT Standards and
frastructure consume signifiRegulations
cant amounts of electricity,
Green IT Resources
placing a heavy burden on our
electric grids and contribut-
Inside
24
IT Pro January/February 2008
ing to greenhouse gas emissions. Additionally,
IT hardware poses severe environmental problems both during its production and its disposal. IT is a significant and growing part of the
environmental problems we face today. We are
obliged to minimize or eliminate where possible
the environmental impact of IT to help create a
more sustainable environment.
To reduce IT’s environmental problems and
to create a sustainable environment, we call
upon the IT sector as well as every computer
user to green their IT systems, as well as the way
they use these systems. We are legally, ethically,
and socially required to green our IT products,
applications, services, and practices. Green IT
benefits the environment by improving energy
efficiency, lowering greenhouse gas emissions,
using less harmful materials, and encouraging
Published by the IEEE Computer Society
1520-9209/08/$25.00 © 2008 IEEE
reuse and recycling. Factors such as environmental legislation, the rising cost of waste disposal, corporate images, and public perception
give further impetus to the green IT initiative.
Green IT is a hot topic today and will continue to be an important issue for several years
to come. To foster green IT, we should understand: What are the key environmental impacts
arising from IT? What are the major environmental IT issues that we must address? How
can we make our IT infrastructure, products,
services, operations, applications, and practices
environmentally sound? What are the regulations or standards with which we need to comply? How can IT assist businesses and society
at large in their efforts to improve our environmental sustainability?
In this article, we address these questions
and examine related issues. We then present a
holistic approach to greening IT. Additionally,
we propose a green IT strategy for enterprises
and outline specific ways to minimize IT’s environmental impact.
Environmental Issues and Problems
The growing accumulation of greenhouse
gases is changing the world’s climate and weather patterns, creating droughts in some countries
and floods in others. It’s slowly pushing global
temperatures higher, posing serious problems
to the world (see http://egj.lib.uidaho.edu/index.
php/egj/article/view/3205/3175). For instance,
2005 was the warmest year on record, and the
10 warmest years have all occurred since 1980.
Global data shows that storms, droughts, and
other weather-related disasters are growing
more severe and more frequent.
To stop the accumulation of greenhouse gases
in the atmosphere, global emissions would have
to stop growing. Electricity is a major cause of
climate change, because the coal or oil that helps
generate electricity also releases carbon dioxide, pollutants, and sulfur into the atmosphere.
These emissions can cause respiratory disease,
smog, acid rain, and global climate change. Reducing electric power consumption is a key to
reducing carbon dioxide emissions and their impact on our environment and global warming.
With this in mind, let’s focus on what each of
us—as IT professionals, members of the IT industry, and IT users—can do individually and
collectively to create a sustainable environment.
Let’s examine IT’s environmental impact and
consider green IT measures that we can adopt.
IT’s environmental impact
IT affects our environment in several different ways. Each stage of a computer’s life, from
its production, throughout its use, and into its
disposal, presents environmental problems.
Manufacturing computers and their various electronic and non-electronic components consumes electricity, raw materials,
chemicals, and water, and generates hazardous waste. All these directly or indirectly increase carbon dioxide emissions and impact
the environment.
Each PC in use generates
about a ton of carbon
dioxide every year.
The total electrical energy consumption by
servers, computers, monitors, data communications equipment, and cooling systems for
data centers is steadily increasing. This increase in energy consumption results in increased greenhouse gas emissions. Each PC
in use generates about a ton of carbon dioxide
every year.
Computer components contain toxic materials. Increasingly, consumers discard a large
number of old computers, monitors, and other
electronic equipment two to three years after
purchase, and most of this ends up in landfills,
polluting the earth and contaminating water.
The increased number of computers and their
use, along with their frequent replacements,
make the environmental impact of IT a major concern. Consequently, there is increasing
pressure on us—the IT industry, businesses,
and individuals—to make IT environmentally
friendly throughout its lifecycle, from birth to
death to rebirth. As many believe, it’s our social and corporate responsibility to safeguard
our environment.
Green IT
Green IT refers to environmentally sound IT.
It’s the study and practice of designing, manufacturing, using, and disposing of computers,
servers, and associated subsystems—such as
January/February 2008 IT Pro
25
Green Computing
Reduce power consumption
75%
Lower costs
73%
Lower carbon emissions
and environmental impact
56%
vironmentally sustainable IT is the key to
future success.
Benefits of greening IT
Environmental issues impact IT busi55%
ness’ competitive landscape in new ways,
and enterprises with the technology and
47%
Space savings
vision to provide products and services
that address environmental issues will en0%
25%
50%
75%
100%
joy a competitive edge. For example, when
making purchasing, leasing, or outsourc1 Reasons and benefits for using green IT practices.
ing decisions, many customers now consider the service providers’ environmental
monitors, printers, storage devices, and netrecords and initiatives. Businesses face
working and communications systems—effihigher energy costs, and they may also incur adciently and effectively with minimal or no impact
ditional government levies if they don’t address
on the environment. Green IT also strives to
the environmental implications of their pracachieve economic viability and improved systices. Investors and consumers are beginning to
tem performance and use, while abiding by our
demand more disclosures from companies with
social and ethical responsibilities.
regard to their carbon footprint as well as their
Thus, green IT includes the dimensions of
environmental initiatives and achievements, and
environmental sustainability, the economics of
they have started discounting share prices of
energy efficiency, and the total cost of ownercompanies that poorly address the environmenship, which includes the cost of disposal and
tal problems they create. As a result, many busirecycling.
nesses have begun showing their environmental
Green IT spans a number of focus areas and
credentials. For instance, the Carbon Disclosure
activities, including
Project (www.cdproject.net) is a recent initiative
to petition global companies to disclose their
• design for environmental sustainability;
carbon emissions.
• energy-efficient computing;
Adopting green IT practices offers business• power management;
es and individuals financial and other benefits.
• data center design, layout, and location;
IT operations achieve better energy efficiency
• server virtualization;
through green initiatives, which financially
• responsible disposal and recycling;
benefit them, especially when electrical en• regulatory compliance;
ergy is at a premium and energy prices are
• green metrics, assessment tools, and
rising. In a survey by Sun Microsystems Ausmethodology;
tralia (see http://au.sun.com/edge/2007-07/eco.
• environment-related risk mitigation;
jsp?cid=920710) involving 1,500 responses from
• use of renewable energy sources; and
758 large and small organizations in Australia
• eco-labeling of IT products.
and New Zealand, respondents said reducing
power consumption and lowering costs are the
A growing number of IT vendors and users
major reasons for using eco-responsible pracare moving toward green IT and thereby assisttices, followed by a lower environmental impact
ing in building a green society and economy.
and improved system use (see Figure 1).
When consumers are faced with more green
Most companies are bound to prioritize
taxes and regulations, they will favor green IT
environmental issues for environmental,
solutions. However, to build a greener environenergy-efficiency, and cost-control imperament, we must modify or abolish many old and
tives. As concerns, regulations, and marketfamiliar ways of doing things and discover new
based mechanisms to address climate change
methods. Fortunately, the IT industry is interrise, businesses will focus on environmental
ested in handling IT’s environmental issues and
sustainability. Corporate and institutionpursuing new opportunities. Innovations in enal buyers are asking their suppliers to take
Improved systems
performance and use
26
IT Pro January/February 2008
Green use
of IT systems
measures to “green up” their products
and their manufacturing processes. For
instance, companies such as Dell and
Wal-Mart are adopting initiatives that
force their suppliers to adhere to environmentally sound practices.
People have begun to value the environmentally friendly attributes of IT, and in the
next five years, green IT will become a common feature. Companies will offer a range
of new green products and services, and
new business opportunities will emerge.
Green manufacturing
of IT systems
Green IT
Green design
of IT systems
Green disposal
of IT systems
2 Holistic approach to green IT.
A Holistic Approach to Green IT
To comprehensively and effectively address the environmental impacts of IT, we
must adopt a holistic approach that addresses the problems along the following
four complementary paths (see Figure 2):
Green design
Green manufacturing
of computers
Use
reprocessed
material
Reuse parts
• Green use. Reduce the energy consumpRecycle, reprocess
Refurbish,
Redeploy,
materials
upgrade
reuse
tion of computers and other information systems and use them in an
environmentally sound manner.
Use computers
Dispose
• Green disposal. Refurbish and reuse old
judiciously
computers and properly recycle unwanted computers and other electronic
Donate
equipment.
• Green design. Design energy efficient
and environmentally sound components, computers, servers, and cooling 3 Green a computer’s entire lifecycle.
equipment.
• Green manufacturing. Manufacture electronic
tion by making small changes to the ways we use
components, computers, and other associcomputers. Most personal desktop computers
ated subsystems with minimal or no impact
run even when they aren’t being used, because
on the environment.
users needlessly leave them on, wasting electricity. Furthermore, computers generate heat and
By focusing our efforts on these four fronts,
require additional cooling, which adds to the
we can achieve total environmental sustaintotal power consumption and cost for the enability from the IT side and make IT greener
terprise. While the savings in energy costs per
throughout its entire lifecycle (see Figure 3).1
PC may not seem like much, the combined savNext, let’s explore these measures.
ings for hundreds of computers in an enterprise
is considerable. We can reduce PC energy conUsing IT:
sumption by adopting several measures.
Environmentally Sound Practices
A key green objective in using computer systems and operating data centers is to reduce
their energy consumption, thereby minimizing the greenhouse gas emissions.
Reducing energy consumption by PCs
We can significantly reduce energy consump-
Enabling power management features.
Without sacrificing performance, we can program computers to automatically power down
to an energy-saving state when we aren’t using
them. The US Environmental Protection Agency (EPA) estimated that providing computers
with a sleep mode reduces their energy use by
January/February 2008 IT Pro
27
Green Computing
60–70 percent (see http://ecenter.colorado.edu/
energy/projects/green_computing.html).
Because PC use is widespread across any given organization, it’s difficult for the IT staff to
manage their enterprise’s PC power consumption. In this case, a pragmatic approach is to
use software such as Surveyor from Verdiem
(www.verdiem.com) that offers network-level
control over PCs and monitors. The software
places the PC into a lower-power consumption mode, such as shutdown, hibernation, or
standby, and monitors into a sleep mode when
they aren’t being used. It also measures and reports how much power each PC and monitor
consumes. Network managers can remotely
awake the PCs for software upgrades, maintenance, or backup.
Turning off the system when not in use.
This is the most basic energy conservation
strategy for most systems. Many people believe the misconception that a computer’s life
is shortened by turning it on and off, so they
leave their computers on all the time. The
electronic equipment’s life span depends on
its cumulative operational time and its temperature. Turning it off reduces both of these
factors, increasing the life of the equipment.
Manufacturers protect personal computers’
internal circuitry from power damage from
on/off switching, and they design modern
hard drives to operate reliably for thousands
of on/off cycles. Therefore, users actually
benefit from turning off their systems when
they aren’t using them.
Some people are reluctant to switch their
computers on and off a couple of times during
their workday, because they don’t want to wait a
minute or two until the system is ready for use.
However, the energy savings are well worth the
inconvenience of waiting a short time for a computer to reboot or a peripheral to come online.
Using screensavers. A blank screensaver
conserves more power than a screensaver that
displays moving images, which continually interacts with the CPU. But even that reduces the
monitor’s energy consumption by only a small
percentage.
Using thin-client computers. Users can
choose to employ thin-client computers,
28
IT Pro January/February 2008
which draw about a fifth of the power of a
desktop PC.
These measures, though easily adoptable,
wouldn’t become a practical reality without users’
wholehearted willingness and active participation. To make these efforts a success, enterprises
must educate their employees to save energy by
changing their computer habits. Enterprises must
seek their employees’ feedback, address their
concerns, and encourage them to join in green
computing efforts.
Greening data centers
The continued rise of Internet and Web applications is driving the rapid growth of data
centers. Enterprises are installing more servers or expanding their capacity. The number of
server computers in data centers has increased
sixfold to 30 million in the last decade, and
each server draws far more electricity than earlier models. Aggregate electricity use for servers
doubled between 2000 and 2005, most of which
came from businesses installing large numbers
of new servers.2 With energy prices increasing
worldwide, the operational cost of data centers
continues to increase steadily. Besides the cost,
availability of electrical power is becoming a
critical issue for many companies whose data
centers have expanded steadily. The social, financial, and practical constraints involved will
force businesses and IT departments to reduce
energy consumption by data centers.
We can improve data center efficiency by using new energy-efficient equipment, improving airflow management to reduce cooling
requirements, investing in energy management software, and adopting environmentally
friendly designs for data centers and new measures to curb data centers’ energy consumption. According to a recent purchasing survey
(see http://searchdatacenter.techtarget.com/
originalContent/0,289142,sid80_gci1264212,00.
html):
• more than 50 percent of data center professionals who responded to the survey said
they have saved energy through server virtualization;
• 32 percent have made efforts to improve underfloor air-conditioning efficiency;
• 17.5 percent have implemented power-down
features on servers not in use;
• 11 percent have tried DC power in the data
center; and
• only 7.7 percent have tried liquid cooling for
increased data center cooling efficiency.
Though liquid is several hundred times
more efficient than air for cooling hot servers, customers are nonetheless unwilling to
use liquid cooling, perhaps because of the
complexities involved with it. However, if
the high-density computing infrastructure
requires liquid cooling, data center managers may have to adapt to it and deal with the
complexities involved.
In a survey by Sun Microsystems Australia,
80 percent of respondents said they would use
energy-efficient technologies, 63 percent said
they would use power and cooling solutions,
and 60 percent said they would use system virtualization (see http://au.sun.com/edge/200707/eco.jsp?cid=920710).
In the following paragraphs, we outline
three broad measures to greening data centers: energy conservation, eco-friendly design,
and server virtualization.
Energy conservation. Energy costs now
account for nearly 30 percent of a data center’s
operating expenses (see http:/news.zdnet.co.uk/
itmanagement/0,1000000308,39284324,00.
htm), a significant amount of which is spent
on cooling. The IT industry is inventing new ways
to help address this issue. For example, companies
like IBM, Hewlett Packard, SprayCool, and Cooligy
are working on technologies such as liquid cooling, nano fluid-cooling systems, and in-server, inrack, and in-row cooling. Other innovative ways
of making a data center more environmentally
friendly include using new high-density servers,
using hydrogen fuel cells as alternative green power sources, and applying virtualization technologies that reduce the total power consumption of
servers and lower the heat generated.
Old mainframe computers are bulky power hogs that demand a lot of cooling. Hence,
major IT vendors are addressing these problems by assisting their customers in migrating
applications from mainframes to servers.
Eco-friendly design. Eco-friendly data center designs use a synthetic white rubber roof,
paint, and carpet that contain a low volatile
organic compound (VOC), countertops made
of recycled products, and energy-efficient mechanical and electrical systems at optimal efficiency. Eco-designs make use of natural light
as well as green power—electricity generated
from solar or wind energy—to run the data
center. Enterprises that adopt eco-friendly designs can get tax incentives and gain a competitive advantage, as more and more customers
want to work with eco-friendly firms.
While building a new data center provides
complete design control, IT professionals can
take measures to reduce heat, add light, and
discard materials that contain toxic chemicals
in existing data centers. For instance, they can
use energy-efficient windows, skylights, and
skytubes, and change the paint and carpet to
a low-VOC variety.
Many American enterprises are adopting the
Leadership in Energy and Environmental Design (LEED) standards maintained by the US
Green Building Council (www.usgbc.org) for
building new data centers. LEED promotes a
“whole-building approach” to sustainability, focusing on five key areas: sustainable site development, water savings, energy efficiency, materials
selection, and indoor environmental quality.
Virtualization. Virtualization is a key strategy to
reduce data center power consumption (see www.
infoworld.com/archives/t.jsp?N=s&V=85855).
With virtualization, one physical server hosts
multiple virtual servers. Virtualization enables
data centers to consolidate their physical server infrastructure by hosting multiple virtual
servers on a smaller number of more powerful
servers, using less electricity and simplifying
the data center. Besides getting better hardware
usage, virtualization reduces data center floor
space, makes better use of computing power,
and reduces the data center’s energy demands.
Many enterprises are using virtualization to
curb the runaway energy consumption of data
centers.
To tackle the issue of data centers’ huge power consumption, leading IT enterprises joined
forces in February 2007, to form a nonprofit
group called the Green Grid (www.thegreengrid.org). This group seeks to define and propagate the best energy-efficient practices in data
center operation, construction, and design, and
drive new user-centric metrics and technology
January/February 2008 IT Pro
29
Green Computing
Greening Unwanted Computers: The Three Rs
Unwanted computers and monitors shouldn’t be
thrown away in rubbish bins, as they will then end up
in landfills causing serious environmental problems.
Instead, we should refurbish and reuse or recycle
them in environmentally sound ways. Here we outline
how you can do that.
Reuse
Why do we need to buy new computers for each
and every project or once every two or three years?
We should make use of an older computer if it meets
our requirements. Otherwise, we should give it to
someone who needs it or use functional components
from a retired product. By using the hardware for a
longer period of time, we can reduce the total environmental footprint caused by computer manufacturing and disposal.
Refurbish
We can refurbish and upgrade old computers and
servers to meet new requirements. We can make
an old computer and other IT hardware almost new
again by reconditioning and replacing their parts.
Rather than buying a new computer to our specifications, we can buy refurbished IT hardware in the
market. More enterprises are open to purchasing
refurbished goods, and the market for refurbished IT
equipment is growing.
From the green angle, reusing what we have is
a better long-term way of managing resources.
Fiscally speaking, we can potentially save our cash
flow, and capital expenditures. If these options are
unsuitable, we can donate the equipment to charities or schools or trade in our computers. Charities
refurbish old computers and give them to those
in need.
Recycle
When we can’t reuse computers, even after
considering the prospects of refurbishing, we
must dispose of them properly in environmentally friendly ways. Most unwanted computers
and electronic goods end up in landfills. Electronic waste or e-waste—discarded computers and
electronic goods—is one of the fastest-growing
waste types, and the problem of e-waste is global.
Analysts predict that two-thirds of the estimated
870 million PCs made worldwide in the next five
years will end up in landfills. The United Nations
Environment Program (www.unep.org) estimates
that 20 to 50 million tons of e-waste are generated
worldwide each year, and this is increasing (see
www.unep.org/Documents.Multilingual/Default.
asp?DocumentID=485& ArticleID=5431&l=en).
Computer components contain toxic materials
like lead, chromium, cadmium, and mercury. If we
bury computers in landfills, toxic materials can leach
harmful chemicals into waterways and the environment. If burned, they release toxic gases into the air
we breathe, so if e-waste is not discarded properly, it
can harm the environment and people. In addition,
e-waste can be a valuable source for secondary raw
materials. We should recycle old electronic systems by
taking component material and reprocessing it into
the same material or breaking it down into constituent materials for reuse.
The Waste Electrical and Electronic Equipment
regulations (WEEE; see www.netregs.gov.uk/netregs/
legislation/380525/473094/?lang=e) aim to reduce
the amount of e-waste going to landfills and to increase recovery and recycling rates. The WEEE regulations deal with the following major areas:
➤ separate collection, disposal, and recycling;
➤ standards for e-waste treatment at authorized
facilities; and
➤ collection, recycling, and recovery targets.
Electrical and electronic manufacturers can also apply
WEEE regulations.
standards (for details, see the white papers at
www.thegreengrid.org/gg_content).
No More “Out with the Old”
We shouldn’t throw away old computers, monitors, and other IT hardware anymore, as they
can cause serious environmental problems. We
should try to give life to them in environmentally
sound ways by reusing, refurbishing, or recycling
them. For details see the sidebar, “Greening Unwanted Computers: The Three Rs.”
30
IT Pro January/February 2008
Designing Green Computers
Green computer design aims to reduce the
environmental impact of computers by adopting new technologies and using new techniques
and materials while balancing environmental
compatibility with economic viability and performance. Green design is quickly becoming
a necessary business practice. Many computer
manufacturers are in the process of making
green PCs using nontoxic materials that consume
less electrical power and are easily reassembled.
These new computers are highly upgradable,
thereby extending their useful lifetime.
The move from single-core to dual- and quadcore processors saves power while increasing processing performance. This contrasts
the old method of improving performance of
microprocessors by increasing the frequency
of the chip’s operation, which hugely increases
power consumption and heat generation. A 15percent reduction in frequency could save up
to 50-percent power consumption.
Other initiatives, such as dividing the cache
into segments that are only powered when
required and moving to a 45-nanometer
architecture, also reduces power consumption.
Manufacturers now apply power-reduction
techniques commonly used for laptops, such
as screens that darken the backlight and lighten the display palette as well as flash memory
caches for hard disks, desktops, and servers.
On the data storage front, a smaller number of
higher-capacity drives is up to 50 percent more
energy efficient than the equivalent large number of small-capacity drives.
IT vendors are now investing significant resources in green initiatives such as developing
energy-efficient servers, data center cooling solutions, and new materials and design options.
Recently, Dell, Apple, and other computer
vendors announced their environmental strategy designed to make their computers green
for the long term. Dell aims its new Zero Carbon Initiative at maximizing the energy efficiency of Dell products, and over time plans to
offset its carbon impact. As a key aspect of this
initiative, it requires that its suppliers publicly
report their greenhouse gas emissions. Apple
has said it will reduce or eliminate toxic chemicals present in its new products and more aggressively recycle its old products.
Companies have launched new tools, standards, and product registration to assist
customers in assessing the environmental attributes of PCs, notebooks, servers, and other
hardware. They include Epeat, the Energy Star
4.0 Standard, and the RoHS Directive. For details, see the sidebar “Green IT Standards and
Regulations” on the next page.
Enterprise Green IT Strategy
Each enterprise must develop a holistic, comprehensive green IT strategy, which should be
a component of, and aligned with, an overall
enterprise-wide green strategy. It should then
develop a green IT policy outlining aims, objectives, goals, plans of action, and schedules.
Large enterprises should also appoint an environmental sustainability officer to implement
their green policy and to monitor their progress and achievements.
To green their IT, enterprises can take any
one or a combination of the following three
approaches:1
• Tactical incremental approach. In this approach, an enterprise preserves the existing IT infrastructure and policies and
incorporates simple measures to achieve
their moderate green goals such as reducing energy consumption. These measures
include adopting policies and practices
such as power management, switching off
computers when not in use, using compact
energy-efficient light bulbs, and maintaining an optimal room temperature. These
measures are generally easy to implement
without much cost. However, enterprises
should work toward these measures only as
short-term, ad hoc solutions.
• Strategic approach. In this approach, an enterprise conducts an audit of its IT infrastructure and its use from an environmental
perspective, develops a comprehensive plan
addressing broader aspects of greening its
IT, and implements distinctive new initiatives. For example, an enterprise may
deploy new energy-efficient, environmentally friendly computing systems, or it may
develop and implement new policies on
procurement, operation, and/or disposal
of computing resources. While the primary rationale is still cost efficiency and a
reduced carbon footprint, it also considers other factors such as branding, image
creation, and marketing.
• Deep green approach. This approach expands upon the measures highlighted in
the strategic approach, wherein an enterprise adopts additional measures such as
implementing a carbon offset policy to neutralize greenhouse gas emissions—including
planting trees, buying carbon credits from
one of many carbon exchanges, or using green
power generated from solar or wind energy.
January/February 2008 IT Pro
31
Green Computing
Green IT Standards and Regulations
Green IT standards and regulations, Epeat (www.
epeat.net), the Energy Star 4.0 standard, and the
RoHS Directive (www.rhos.gov.uk) can help you
design green computers and other IT hardware and
classify them based on their environmental attributes.
Epeat
Prompted by the need for an evaluation tool that
allows the selection of electronic products based
on environmental performance, the Green Electronics Council (www.greenelectronicscouncil.org) has
launched the Electronic Product Environmental
Assessment Tool (Epeat; see www.epeat.net). Epeat
assists buyers to evaluate, compare, and select
desktop computers, notebooks, and monitors based
on their environmental attributes. It also helps
manufacturers promote their products as environmentally sound.
Epeat evaluates electronic products on 23 required
criteria and 28 optional criteria, which are grouped
into eight performance categories (see www.
greenelectronicscouncil.org/epeat/criteria.htm):
reducing and eliminating environmentally sensitive materials, selecting materials, designing for the
product’s end of life (such as recycling), product longevity, energy conservation, end-of-life management,
corporate performance, and packaging.
Epeat identifies its registered products as
bronze, silver, or gold. Bronze products meet all
23 required criteria. Silver products meet all 23
required criteria plus at least 14 optional criteria,
and gold products meet all 23 required criteria
plus at least 21 optional criteria. Manufacturers
can pick and choose among the optional criteria
to boost their Epeat score to achieve a higher level
of registration.
All Epeat-registered computers have reduced levels
of cadmium, lead, and mercury to better protect
human health. These are more energy-efficient and
easier to upgrade and recycle. In fact, manufacturers
of Epeat products must offer safe recycling options for
the products when they’re no longer usable.
Epeat recognizes several desktop computers,
laptops, and monitors from leading manufacturers as
green products (www.epeat.net/Search.aspx). Some
computer contracts issued by major government
agencies in the US as well as some private enterprises
already reference Epeat.
Energy Star 4.0 Standard
The new Energy Star 4.0 standard regulates energy
performance of external and internal power supplies
and gives power consumption specifications for idle,
sleep, and standby modes for a number of different devices including PCs, desktops, and gaming
consoles. Computers meeting the new requirements
will save energy in all modes of operation. Regulations for computers in idle mode are new, as previous
standards addressed only sleep and standby modes.
The new specifications require OEMs to educate users
about power management.
RoHS Directive
The Restriction of Hazardous Substances in Electrical and Electronic Equipment Directive (RoHS;
see www.rohs.gov.uk and www.netregs.gov.uk/
netregs/275207/1628456/?lang=_e) aims to restrict
the use of certain hazardous substances. It also bans
placing new electrical and electronic equipment on
the European Union market if it contains more than
the agreed-upon levels of lead, cadmium, mercury,
hexavalent chromium, or flame retardants.
An enterprise may also encourage its employees to go green with their home computers
by offering incentives such as planting a tree,
buying carbon credits, supplying them with
free power management software, and offering computer recycling/trade-in provisions.
Hopefully, in the beginning enterprises will
adopt an incremental approach and then move
progressively by implementing other initiatives
to reach a full green IT status.
Using IT for Environmental
Sustainability
Besides IT itself being green, it can sup-
32
IT Pro January/February 2008
port, assist, and leverage other environmental initiatives by offering innovative
modeling, simulation, and decision support
tools, such as
• software tools for analyzing, modeling, and
simulating environmental impact, and environmental risk management;
• platforms for eco-management, emission
trading, or ethical investing;
• tools for auditing and reporting energy consumption and savings and for monitoring
greenhouse gas emissions;
• environmental
knowledge
management
systems, including geographic informa-
tion systems and environmental metadata
standards;
• urban environment planning tools and
systems;
• technologies and standards for interoperable
environmental monitoring networks and
smart in situ sensors networks; and
• integrating and optimizing existing environmental monitoring networks and new easy
plug-in sensors.
Green IT Resources
The following are some helpful electronic resources:
➤ CIO’s “Green IT” page (http://advice.cio.com/
taxonomy/term/27/0) discusses how to stay out of
the red with an environmental approach. It covers
news, comments on new developments and initiatives, and offers opinions and advice.
➤ InfoWorld’s “Sustainable IT” page (http://weblog.
infoworld.com/sustainableit) tracks trends toward a
greener, more energy-efficient IT.
➤ Greener Computing (www.greenercomputing.com)
is a resource for environmentally friendly computers.
➤ The Green Wombat blog (http://blogs.business2.
com/greenwombat) focuses on the environment
and technology and covers energy efficiency, green
computing, carbon credits, and other areas.
➤ The Data Center Knowledge newsletter (www.
datacenterknowledge.com) presents news and
analysis about data centers, managed hosting, and
disaster recovery.
➤ InfoWorld’s Green Tech newsletter (subscribe at
http://subscribe.infoworld.com/cgi-win/ifwd.
cgi?m=newsletter) presents how businesses are
examining how they use their resources and exploring ways to save energy, materials, and money with
green IT.
➤ GreenBiz (www.greenbiz.com) is the leading information resource on how to align environmental
responsibility with business success.
Using IT to Create Green Awareness
In addition to moving itself in a greener direction and leveraging other environmental initiatives, IT could help create green awareness
among IT professionals, businesses, and the general public by assisting in building communities,
engaging groups in participatory decisions, and
supporting education and green advocacy campaigns. Along these lines, tools such as environmental Web portals, blogs, wikis, and interactive
simulations of the environmental impact of an
activity could offer assistance.
I
T is part of the environmental problem, and
it can be part of the solution. Green IT is
an economic, as well as an environmental,
imperative. Greening IT is and will continue to
be a necessity, not an option. Green IT represents a dramatic change in priority in the IT
industry. So far, the industry has been focusing
on IT equipment processing power and associated equipment spending. It’s not been concerned with other requirements such as power,
cooling, and data center space. However, going
forward, the IT industry will need to deal with
all of the infrastructure requirements and the
environmental impact of IT and its use.
The challenges of green IT are immense;
however, recent developments indicate that
the IT industry has the will and conviction
to tackle our environmental issues head-on
(see the “Green IT Resources” sidebar). Companies can benefit by taking these challenges
as strategic opportunities. The IT sector and
users must develop a positive attitude toward
addressing environmental concerns and
adopt forward-looking, green-friendly policies and practices.
References
1.
2.
S. Murugesan, “Going Green with IT: Your Responsibility toward Environmental Sustainability,” Cutter
Business—IT Strategies Executive Report, vol. 10, no. 8,
2007.
S. Pritchard, “IT Going Green: Forces Pulling in Different Directions,” Financial Times, 30 May 2007.
San Murugesan is a professor at Multimedia University
in Malaysia and an adjunct professor at the University
of Western Sydney in Australia. Contact him at san1@
internode.on.net.
For further information on this or any other
computing topic, please visit our Digital Library
at http://www.computer.org/csdl.
January/February 2008 IT Pro
33
www.pewresearch.org
AUGUST 26, 2013
Home Broadband 2013
Some 70% of American adults have a high-speed broadband connection at home; an
additional 10% of Americans lack home broadband but do own a smartphone. And
20% of Americans have neither a home broadband connection nor a smartphone.
Kathryn Zickuhr
Research Associate, Pew Internet Project
Aaron Smith
Senior Researcher, Pew Internet Project
http://pewinternet.org/Reports/2013/Broadband.aspx
FOR FURTHER INFORMATION, CONTACT:
Pew Research Center’s Internet & American Life Project
1615 L St., N.W., Suite 700
Washington, D.C. 20036
Media Inquiries:
202.419.4500
Trends and demographic differences in home broadband adoption
As of May 2013, 70% of American adults ages 18 and older have a high-speed broadband connection at
home, according to a nationally representative survey by the Pew Research Center’s Internet &
American Life Project. This is a small but statistically significant rise from the 66% of adults who said they
had home broadband in April 2012.
Home broadband vs. dial-up, 2000-2013
Among all American adults ages 18 and older, the % who access the internet at home via dial-up or
high-speed broadband connection, over time. As of May 2013, 70% of adults have home broadband.
Dial-up
Broadband
80%
66%
70%
63%
50%
41%
34%
42%
38% 37%
30%
16%
20%
3%
6%
11%
28%
24%
47%
33%
30%
10%
70%
55%
60%
40%
62%
66%
23%
15%
10%
7%
5%
3%
3%
3%
0%
June April March March April March March March April April May Aug April May
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Source: Pew Internet & American Life Project Surveys, March 2000-May 2013. Question wording has
changed slightly over time. Our method for measuring home internet use changed in 2011, which
would contribute to the seeming decline in adoption. See Methods section for more information.
See also: http://pewinternet.org/Trend-Data/Home-Broadband-Adoption.aspx
The demographic factors most correlated with home broadband adoption continue to be educational
attainment, age, and household income. Almost nine in ten college graduates have high-speed internet
at home, compared with just 37% of adults who have not completed high school. Similarly, adults under
age 50 are more likely than older adults to have broadband at home, and those living in households
earning at least $50,000 per year are more likely to have home broadband than those at lower income
levels.
pewinternet.org
2
Home broadband demographics 2013
Among all American adults ages 18 and older, the % in each group who
have a high-speed broadband connection at home
% with home
broadband
All Americans ages 18+ (n=2,252)
70%
a
Men (n=1,029)
71
b
Women (n=1,223)
69
Race/ethnicity
bc
a
White, Non-Hispanic (n=1,571)
74
b
Black, Non-Hispanic (n=252)
64
c
Hispanic (English- and Spanish-speaking) (n=249)
53
c
Age
cd
a
18-29 (n=404)
80
b
30-49 (n=577)
78
c
50-64 (n=641)
69
d
65+ (n=570)
43
cd
d
Education attainment
a
No high school diploma (n=580)
37
b
High school grad (n=374)
57
c
Some College (n=298)
78
d
College + (n=582)
89
a
ab
abc
Household income
a
Less than $30,000/yr (n=417)
54
b
$30,000-$49,999 (n=320)
70
c
$50,000-$74,999 (n=279)
84
d
$75,000+ (n=559)
88
a
ab
ab
Urbanity
c
a
Urban (n=763)
70
b
Suburban (n=1,037)
73
c
Rural (n=450)
62
c
Source: Pew Research Center’s Internet & American Life Project Spring Tracking
Survey, April 17 – May 19, 2013. N=2,252 adults ages 18+. Interviews were
conducted in English and Spanish and on landline and cell phones. The margin of
error for results based on all adults is +/- 2.3 percentage points.
a
Note: Percentages marked with a superscript letter (e.g., ) indicate a statistically
significant difference between that row and the row designated by that
superscript letter, among categories of each demographic characteristic (e.g. age).
pewinternet.org
3
Smartphones and broadband
In recent years internet-connected mobile devices such as smartphones have exploded in popularity,
offering an alternate form of “home” internet access. Today 56% of American adults own a smartphone
of some kind, compared with 70% who have broadband at home. 1
There is no widespread consensus as to whether 3G or 4G smartphones qualify as “broadband” speed,
and many would question whether they offer the same utility to users as a dedicated home internet
connection (activities such as updating a resume, filing taxes, or viewing educational content are
certainly more challenging on a smartphone operating over a cell phone network, than on a broadbandconnected home computer). For these reasons, smartphones are qualitatively distinct enough that we
do not include them in our standard definition of what constitutes a “broadband user.”
At the same time, smartphones do offer a potential source of online access to individuals who might
otherwise lack the ability to go online at all from within the home, even if that access is somewhat
limited in comparison. And indeed, 10% of Americans indicate that they do not have a broadband
connection at home but that they do own a smartphone (another way to say this is that 32% of nonbroadband users own a smartphone). If we include that 10% of Americans with the 70% who have
traditional broadband, that means that 80% of Americans have either a broadband connection, a
smartphone, or both. Here is how the 80% breaks down:
46% of Americans have both a home broadband connection and a smartphone
24% have a home broadband connection, but not a smartphone
10% have a smartphone, but not a home broadband connection
The remaining 20% of Americans have neither a home broadband connection nor a smartphone.
Including smartphones in the definition of home broadband access helps narrow the differences
between some demographic groups, but widens the gap between others. Differences between racial
and ethnic groups are an example of smartphones narrowing the “broadband gap”: While blacks and
Latinos are less likely to have access to home broadband than whites, their use of smartphones nearly
eliminates that difference.2
On the other hand, including smartphones in our broadband definition actually exacerbates differences
in broadband adoption rates between young and old. Looking just at our standard definition of home
broadband adoption, we find that 80% of young adults ages 18-29 have a high-speed broadband at
home, compared with 43% of seniors ages 65 and older—a gap of 37 percentage points. If we include
smartphone ownership in our definition of home broadband, this gap actually increases to 49
percentage points, because young adults are more likely than seniors to own smartphones as well.
Adding smartphone ownership to home broadband use, we see that the proportion of young adults who
have ”home broadband” under this definition increases from 80% to 95%, while including smartphones
has no discernible impact on access rates for seniors—the 46% of seniors who have broadband or a
smartphone is little different from the 43% who have broadband at all.
1
Aaron Smith, “Smartphone Ownership 2013.” http://pewinternet.org/Reports/2013/Smartphone-Ownership2013.aspx
2
The US Census Bureau has found similar trends in its own research. See Thom File, U.S. Census Bureau,
“Computer and Internet Use in the United States.” Issued May 2013, based on the July 2011 Current Population
Survey. http://www.census.gov/prod/2013pubs/p20-569.pdf pp 11-13.
pewinternet.org
4
Broadband and smartphone adoption
Among all American adults ages 18 and older, the % in each group who…
All adults
a
Men (n=1029)
Women (n=1223)
b
Race/ethnicity
a
b
White, Non-Hispanic (n=1571)
Black, Non-Hispanic (n=252)
Hispanic (n=249)
c
Age
a
18-29 (n=404)
Have broadband
at home
Have home
broadband or
smartphone
Difference
70%
80%
+10
71
81
+10
69
78
+9
bc
80
+6
c
64
79
+15
53
75
+22
74
cd
80
cd
bcd
+15
cd
+11
95
b
30-49 (n=577)
78
c
50-64 (n=641)
69
77
d
+8
43
46
+3
37
52
+15
a
a
+13
ab
+9
abc
+4
65+ (n=570)
d
Education attainment
a
No high school diploma (n=168)
d
b
High school grad (n=630)
57
c
Some College (n=588)
78
d
College + (n=834)
ab
abc
89
89
70
87
93
Household income
a
b
c
d
Less than $30,000/yr (n=580)
$30,000-$49,999 (n=374)
$50,000-$74,999 (n=298)
$75,000+ (n=582)
54
67
a
b
+9
ab
+7
ab
+7
c
+10
c
70
ab
84
ab
88
79
91
95
+13
Urbanity
a
Urban (n=763)
c
70
c
80
b
Suburban (n=1037)
73
83
+10
c
Rural (n=450)
62
70
+8
Source: Pew Research Center’s Internet & American Life Project Spring Tracking Survey, April 17 – May 19,
2013. N=2,252 adults ages 18+. Interviews were conducted in English and Spanish and on landline and cell
phones. The margin of error for results based on all adults is +/- 2.3 percentage points.
a
Note: Percentages marked with a superscript letter (e.g., ) indicate a statistically significant difference
between that row and the row designated by that superscript letter, among categories of each demographic
characteristic (e.g. age).
pewinternet.org
5
Further reading on broadband access and adoption
The Census Bureau’s July 2011 Current Population Survey found that about 98% of U.S. households live
in areas where they have access to broadband Internet connections as of July 2011, although only 69%
of households used broadband at home. 3 (According to the National Telecommunications and
Information Administration and the Economics and Statistics Administration, the proportion of
Americans households with home broadband rose to 72% as of October 2012.) In April 2009, Pew
Internet asked adults who had dial-up internet at home what it would take for them to switch to a
broadband connection. A plurality (35%) said the price would have to fall, 17% said it would have to
become available where they live, and one in five (20%) said nothing would get them to change.4
In May 2010, Pew Internet found that Americans generally feel that individuals who do not have
broadband at home are at a major disadvantage when it comes to finding out about job opportunities or
learning career skills, or when getting health information, learning new things for personal enrichment,
and using government services. However, nearly half of adults felt that those without broadband access
are not at a disadvantage when it comes to keeping up with news and information or keeping up with
what is happening in one’s local community. Minority Americans were more likely to see a lack of
broadband access as a major hindrance to accomplishing numerous tasks, while older adults (specifically
those ages 65 and older) were less likely to see the drawbacks of a lack of high-speed access. 5
3
“Exploring the Digital Nation: America’s Emerging Online Experience.” National Telecommunications and
Information Administration and Economics and Statistics Administration, June 2013.
http://www.ntia.doc.gov/report/2013/exploring-digital-nation-americas-emerging-online-experience pp 1-2.
See also: http://www.broadbandmap.gov/
4
John Horrigan, “Home Broadband Adoption 2009.” http://pewinternet.org/Reports/2009/10-Home-BroadbandAdoption-2009.aspx
5
Aaron Smith, “Home Broadband 2010.” http://www.pewinternet.org/Reports/2010/Home-Broadband-2010.aspx
One in ten Americans (11%) said that expanding high speed access to everyone in the country should be a “top
priority,” while three in ten (30%) felt that it is “important, but a lower priority.” One quarter each said that federal
promotion of broadband expansion is “not too important” (27%) or “should not be done” (26%).
pewinternet.org
6
Survey Questions
Spring 2013 Tracking Survey
Final Topline
5/21/2013
Data for April 17-May 19, 2013
Princeton Survey Research Associates International for
the Pew Research Center’s Internet & American Life Project
Sample: n=2,252 national adults, age 18 and older, including 1,127 cell phone interviews
Interviewing dates: 04.17.2013 – 05.19.2013
Margin of error is plus or minus 2.3 percentage points for results based on Total [n=2,252]
Margin of error is plus or minus 2.5 percentage points for results based on all internet users [n=1,895]
Margin of error is plus or minus 2.4 percentage points for results based on all cell phone owners [n=2,076]
Do you use the internet, at least occasionally?
EMLOCC Do you send or receive email, at least occasionally?
EMINUSE Do you use the internet or email, at least occasionally?
INTMOBDo you access the internet on a cell phone, tablet or other mobile handheld device, at
least occasionally?6
INTUSE
USES INTERNET
Current
December 2012
September 2012
August 2012
April 2012
February 2012
85
81
81
85
82
80
DOES NOT USE
INTERNET
15
19
19
15
18
20
INTUSE/EMLOCC/EMINUSE/INTMOB continued...
6
The definition of an internet user varies from survey to survey. In the current survey, half the sample was asked
INTUSE/EMLOCC/INTMOB and half was asked EMINUSE/INTMOB. Current results are for both forms combined.
Throughout the current topline, total internet users are defined as those who answered yes to any question
INTUSE, EMLOCC, EMINUSE or INTMOB. From April 2012 thru December 2012, an internet user is someone who
uses the internet at least occasionally, sends/receives email at least occasionally or accesses the internet a mobile
device (three-part definition with question wording “Do you use the internet, at least occasionally?” OR “Do you
send or receive email, at least occasionally?” OR “Do you access the internet on a cell phone, tablet or other
mobile handheld device, at least occasionally?”). From January 2005 thru February 2012, an internet user is
someone who uses the internet at least occasionally or sends/receives email at least occasionally (two-part
definition with question wording “Do you use the internet, at least occasionally?” OR “Do you send or receive
email, at least occasionally?”). Prior to January 2005, an internet user is someone who goes online to access the
internet or to send and receive email (question wording “Do you ever go online to access the Internet or World
Wide Web or to send and receive email?”).
pewinternet.org
7
INTUSE/EMLOCC/ EMINUSE/INTMOB continued...
December 2011
August 2011
May 2011
January 2011
December 2010
November 2010
September 2010
May 2010
January 2010
December 2009
September 2009
April 2009
December 2008
November 2008
August 2008
July 2008
May 2008
April 2008
January 2008
December 2007
September 2007
February 2007
December 2006
November 2006
August 2006
April 2006
February 2006
December 2005
September 2005
June 2005
February 2005
January 2005
Nov 23-30, 2004
November 2004
July 2004
June 2004
March 2004
February 2004
November 2003
August 2003
June 2003
May 2003
March 3-11, 2003
February 2003
pewinternet.org
USES INTERNET
DOES NOT USE
INTERNET
82
78
78
79
77
74
74
79
75
74
77
79
74
74
75
77
73
73
70
75
73
71
70
68
70
73
73
66
72
68
67
66
59
61
67
63
69
63
64
63
62
63
62
64
18
22
22
21
23
26
26
21
25
26
23
21
26
26
25
23
27
27
30
25
27
29
30
32
30
27
27
34
28
32
33
34
41
39
33
37
31
37
36
37
38
37
38
36
8
HOME3NW
Do you ever use the internet or email at HOME?7
Based on all internet users [N=1,895]
Current
December 2012
April 2012
February 2012
August 2011
May 2011
January 2011
December 2010
November 2010
September 2010
May 2010
January 2010
December 2009
September 2009
April 2009
December 2008
November 2008
August 2008
July 2008
May 2008
December 2007
September 2007
February 2007
November 2006
February 2006
June 2005
July 2004
March 2004
YES
NO
DON’T KNOW
REFUSED
90
90
89
90
90
88
89
95
95
95
94
94
93
92
91
92
93
93
93
95
94
93
95
93
94
90
94
92
10
10
11
10
10
12
11
4
4
5
6
6
6
6
8
6
7
7
7
6
7
6
5
7
6
10
7
8
0
0
0
*
0
0
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
0
0
*
0
*
0
*
*
*
*
*
*
*
*
*
*
------------
7
In December 2012, question wording was: “Do you ever use the internet AT HOME?” In January 2011 and May
2011, question wording was: “Do you ever use the internet or email from home?” December 2010 and earlier
trend wording was as follows: “About how often do you use the internet or email from... HOME – several times a
day, about once a day, 3-5 days a week, 1-2 days a week, every few weeks, less often or never?” Results shown
here for “YES” reflect combined “Several times a day,” “About once a day,” “3-5 days a week,” “1-2 days a week,”
“Every few weeks,” and “Less often” responses. Results shown here for “NO” reflect “Never” responses.
pewinternet.org
9
MODEM4B
At home, do you connect to the internet through a dial-up telephone line, or do you have some other type of connection,
such as a DSL-enabled phone line, a cable TV modem, a wireless connection, or a fiber optic connection such as FIOS?8
Based on those who use the internet at home
Current [N=1,727]
Dec 2012 [N=1,645]
Nov 2012 [N=1,770]
April 2012 [N=1,631]
Feb 2012 [N=1,572]
Aug 2011 [N=1,565]
May 2011 [N=1,518]
Jan 2011 [N=1,610]
Dec 2010 [N=1,731]
Nov 2010 [N=1,560]
Sept 2010 [N=1,947]
May 2010 [N=1,659]
Jan 2010 [N=1,573]
Dec 2009 [N=1,582]
Sept 2009 [N=1,584]
April 2009 [N=1,567]
DIAL-UP
TOTAL
HIGH
SPEED
4
4
4
4
4
5
6
4
6
6
7
7
7
9
7
9
92
90
88
90
90
89
88
88
85
86
86
86
88
86
87
86
--------DSL
--------CABLE
MODEM
--------WIRELESS
18
18
18
20
21
22
25
28
27
28
29
27
29
28
30
29
31
33
34
33
35
34
31
33
33
33
31
33
38
37
37
36
33
30
28
30
28
26
29
22
19
20
20
20
18
17
15
15
--------FIBER
OPTIC
8
5
6
6
5
5
4
5
5
5
6
5
4
3
4
4
9
--------T-1
--------(VOL.)
OTHER
BROADBAND
--------(VOL.)
BROADBAND
COMBO
(VOL.)
NO HOME
NET
ACCESS
(VOL.)
ACCESS
NET ON
CELL
ONLY
n/a
1
1
*
1
*
*
1
*
1
1
1
*
1
*
1
1
2
2
1
1
2
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
1
*
0
*
*
*
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
1
*
*
*
*
1
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
1
2
2
1
2
1
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
(VOL.)
NONE OF
THE
ABOVE
10
DK
8
December 2012 and earlier trend question wording included “T-1” as a read category. From September 2009 thru January 2010, the question asking about
type of home internet connection (MODEM) was form split. MODEMA was asked of Form A respondents who use the internet from home. MODEMB was
asked of Form B respondents who use the internet from home. Trend results shown here reflect combined MODEMA and MODEMB percentages. Form B
respondents who answered “satellite,” fixed wireless provider,” or “other wireless such as an Aircard or cell phone” have been combined in the “Wireless”
column in the table.
9
In Sept. 2007 and before, “Fiber optic connection” and “T-1 connection” were collapsed into one category. Percentage for “Fiber optic connection” reflects
the combined “Fiber-optic/T-1” group.
10
May 2011 and earlier trend percentages for “None of the above” reflect “Other (SPECIFY)” responses.
REF.
*
2
*
*
3
1
*
4
*
*
4
*
1
3
*
1
3
*
1
3
1
2
4
1
2
6
2
2
4
2
2
4
1
2
4
1
1
3
1
2
4
1
2
3
2
2
3
1
MODEM4B continued...
MODEM4B continued...
DIAL-UP
TOTAL
HIGH
SPEED
13
12
13
14
15
18
20
23
28
35
44
47
48
55
62
80
82
81
81
79
77
73
70
68
61
53
50
50
42
35
Dec 2008 [N=1,538]
Nov 2008 [N=1,481]
Aug 2008 [N=1,543]
July 2008 [N=1,797]
May 2008 [N=1,463]
Dec 2007 [N=1,483]
Sept 2007 [N=1,575]
Feb 2007 [N=1,406]
Aug 2006 [N=1,787]
Dec 2005 [N=1,715]
June 2005 [N=1,204]
Feb 2005 [N=1,287]
Jan 2005 [N=1,261]
Feb 2004 [N=1,241]
Nov 2003 [N=1,199]
pewinternet.org
--------DSL
--------CABLE
MODEM
30
33
37
35
36
34
34
35
34
29
24
22
21
18
13
32
34
30
30
31
31
30
28
30
27
25
25
26
23
21
--------WIRELESS
--------FIBER
OPTIC
--------T-1
--------(VOL.)
OTHER
BROADBAND
15
13
10
13
9
10
8
6
3
4
3
3
2
1
1
3
3
3
3
2
2
2
1
1
1
1
1
1
1
*
*
*
1
1
*
1
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
--------(VOL.)
BROADBAND
COMBO
(VOL.)
NO HOME
NET
ACCESS
(VOL.)
ACCESS
NET ON
CELL
ONLY
(VOL.)
NONE OF
THE
ABOVE
DK
REF.
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
5
5
5
4
5
3
6
6
3
3
1
3
1
2
2
----------------
11
Methods
This report is based on the findings of a survey on Americans' use of the Internet. The results in this
report are based on data from telephone interviews conducted by Princeton Survey Research Associates
International from April 17 to May 19, 2013, among a sample of 2,252 adults, age 18 and older.
Telephone interviews were conducted in English and Spanish by landline (1,125) and cell phone (1,127,
including 571 without a landline phone). For results based on the total sample, one can say with 95%
confidence that the error attributable to sampling is plus or minus 2.3 percentage points. For results
based on Internet users11 (n=1,895), the margin of sampling error is plus or minus 2.5 percentage
points. In addition to sampling error, question wording and practical difficulties in conducting telephone
surveys may introduce some error or bias into the findings of opinion polls.
A combination of landline and cellular random digit dial (RDD) samples was used to represent all adults
in the United States who have access to either a landline or cellular telephone. Both samples were
provided by Survey Sampling International, LLC (SSI) according to PSRAI specifications. Numbers for the
landline sample were drawn with equal probabilities from active blocks (area code + exchange + twodigit block number) that contained three or more residential directory listings. The cellular sample was
not list-assisted, but was drawn through a systematic sampling from dedicated wireless 100-blocks and
shared service 100-blocks with no directory-listed landline numbers.
New sample was released daily and was kept in the field for at least five days. The sample was released
in replicates, which are representative subsamples of the larger population. This ensures that complete
call procedures were followed for the entire sample. At least 7 attempts were made to complete an
interview at a sampled telephone number. The calls were staggered over times of day and days of the
week to maximize the chances of making contact with a potential respondent. Each number received at
least one daytime call in an attempt to find someone available. For the landline sample, interviewers
asked to speak with the youngest adult male or female currently at home based on a random rotation. If
no male/female was available, interviewers asked to speak with the youngest adult of the other gender.
For the cellular sample, interviews were conducted with the person who answered the phone.
Interviewers verified that the person was an adult and in a safe place before administering the survey.
Cellular sample respondents were offered a post-paid cash incentive for their participation. All
interviews completed on any given day were considered to be the final sample for that day.
Weighting is generally used in survey analysis to compensate for sample designs and patterns of nonresponse that might bias results. A two-stage weighting procedure was used to weight this dual-frame
sample. The first-stage corrected for different probabilities of selection associated with the number of
11
Internet user definition includes those who use the internet or email at least occasionally or access the internet
on a mobile handheld device at least occasionally.
pewinternet.org
12
adults in each household and each respondent’s telephone usage patterns.12 This weighting also adjusts
for the overlapping landline and cell sample frames and the relative sizes of each frame and each
sample.
The second stage of weighting balances sample demographics to population parameters. The sample is
balanced to match national population parameters for sex, age, education, race, Hispanic origin, region
(U.S. Census definitions), population density, and telephone usage. The Hispanic origin was split out
based on nativity; U.S born and non-U.S. born. The basic weighting parameters came from the US
Census Bureau’s 2011 American Community Survey data. The population density parameter was derived
from Census 2010 data. The telephone usage parameter came from an analysis of the January-June
2012 National Health Interview Survey.
Following is the full disposition of all sampled telephone numbers:
12
i.e., whether respondents have only a landline telephone, only a cell phone, or both kinds of telephone.
pewinternet.org
13
Sample Disposition
Landline
Cell
41,291
24,698
Total Numbers Dialed
1,755
1,516
12
24,344
2,038
11,626
28.2%
411
88
---9,674
226
14,299
57.9%
Non-residential
Computer/Fax
Cell phone
Other not working
Additional projected not working
Working numbers
Working Rate
679
3,442
41
7,464
64.2%
75
3,668
16
10,540
73.7%
No Answer / Busy
Voice Mail
Other Non-Contact
Contacted numbers
Contact Rate
450
5,786
1,228
16.5%
1,537
7,097
1,906
18.1%
Callback
Refusal
Cooperating numbers
Cooperation Rate
45
---1,183
96.3%
68
684
1,154
60.5%
Language Barrier
Child's cell phone
Eligible numbers
Eligibility Rate
58
1,125
95.1%
27
1,127
97.7%
Break-off
Completes
Completion Rate
10.0%
13.0%
Response Rate
The disposition reports all of the sampled telephone numbers ever dialed from the original telephone
number samples. The response rate estimates the fraction of all eligible respondents in the sample that
were ultimately interviewed. At PSRAI it is calculated by taking the product of three component rates:
Contact rate – the proportion of working numbers where a request for interview was made
Cooperation rate – the proportion of contacted numbers where a consent for interview was at
least initially obtained, versus those refused
Completion rate – the proportion of initially cooperating and eligible interviews that were
completed
Thus the response rate for the landline sample was 10 percent. The response rate for the cellular sample
was 13 percent.
pewinternet.org
14
Purchase answer to see full
attachment