Need help with this 2 tes
Question 1

A(n) ________ occurs when ________ independent variable(s) have an effect in combination with one another.
interaction; two or more
interaction; two or less
main effect; two or more
main effect; two or less
2.5 points
Question 2

Interested in the effects of different kinds of instruction on videogame performance, Martin asks 30 college freshmen to each play an hour of Ratchet and Klank. Participants are randomly assigned to one of three instruction groups: (1) complete the tasks as quickly as possible, (2) conserve as much health as possible (i.e., play more carefully), or (3) find gold bolts (worth lots of money in equipment and ammunition). If Martin averages the scores for each instruction group and then compares them, any differences in the means of the instruction groups reflect:
individual differences in handeye coordination.
inherent differences in the ability of the college freshmen to play video games.
withingroups variance.
betweengroups variance.
2.5 points
Question 3

Why can't a researcher just run multiple t tests when the independent variable has more than two levels?
As you run more statistical tests, it becomes harder and harder to reject the null hypothesis.
As you run more statistical tests, the probability that you will make a Type I error in one of the tests increases.
As you run more statistical tests, you lose degrees of freedom.
As you run more statistical tests, the probability that you will make a Type III error in one of those tests increases.
2.5 points
Question 4

________ is a term used to describe an independent variable in a study with more than one independent variable.
Interaction
Main effect
Effect
Factor
2.5 points
Question 5

(Table: Coping with Pain) The cells of this study reflect an interaction between coping style and cognitive strategy. Which statement best describes the interaction?
People using both distraction and sensationmonitoring cognitive strategies were able to keep their hand in the ice water for longer than 60 seconds, on average.
People using a sensationmonitoring strategy were able to keep their hand in the ice water for longer.
People using a distraction strategy were able to keep their hand in the ice water for longer.
The effect of cognitive strategy depended on the coping style of the participant. Those with an avoiding coping style kept their hand in the ice water longer when using a distraction strategy, but those with a monitoring coping style kept their hand in the ice water longer when using a sensationmonitoring strategy.
2.5 points
Question 6

A fiveway ANOVA has:
five dependent variables and two independent variables.
one dependent variable and five independent variables.
one dependent variable and four independent variables.
five dependent variables and five independent variables.
2.5 points
Question 7

The F ratio is calculated by:
dividing a measure of withingroups variability by a measure of betweengroups variability.
averaging the results from the t tests for all possible twogroup comparisons.
dividing a measure of betweengroups variability by a measure of withingroups variability.
initially squaring all the scores.
2.5 points
Question 8

According to Cohen's conventions, an R2 of 0.19 is considered to be a(n) ________ effect size.
small
medium
large
erroneous
2.5 points
Question 9

Given a scale dependent variable and a nominal independent variable with three or more levels, we could use a(n) ________ to analyze the data.
PRE test
z test
t test
ANOVA
2.5 points
Question 10

A researcher wants to statistically test whether gender affects math test scores. Which test should the researcher use?
oneway ANOVA
twoway ANOVA
threeway ANOVA
withingroups ANOVA
2.5 points
Question 11

In a twoway ANOVA, the researcher makes decisions regarding ________ null hypotheses.
three separate
two separate
three interdependent
two interdependent
2.5 points
Question 12

A researcher wants to examine people's preference for pets by having 10 people act as “foster owners” for four different types of family pets: dogs, cats, birds, and fish. The participants will foster each type of pet for one week, and a scale measure will be used to assess preference. What research design should be used?
oneway betweengroups ANOVA
correlation
oneway withingroups ANOVA
pairedsamples t tests
2.5 points
Question 13

The F ratio is a ratio of:
two (or more) sample means.
two variances.
sample means divided by sample variances.
two sumofsquares estimates.
2.5 points
Question 14

A posthoc test is warranted when:
the F is significant and there are more than two groups.
we fail to reject the null hypothesis in an ANOVA.
we reject the null hypothesis when performing an independentgroups t test.
we have an a priori prediction about which group means will differ.
2.5 points
Question 15

A hypothesis test with two nominal independent variables and a scale dependent variable is a:
oneway ANOVA.
twoway ANOVA.
twogroups t test.
twogroups z test.
2.5 points
Question 16

A withingroups ANOVA is used when we have ________ independent variable(s) with ________ levels.
1; more than 2
2; more than 2
1; less than 2
2; less than 2
2.5 points
Question 17

Which degrees of freedom value is unique to the oneway withingroups ANOVA?
betweengroups
subjects
withingroups
total
2.5 points
Question 18

The Bonferroni, Scheffé, and Tukey are all examples of:
hypothesis tests.
posthoc tests.
effect size statistics.
confidence intervals.
2.5 points
Question 19

In Zinman and Zitzewitz's (2009) research on snowfall reports, they found the following interaction:
the amount of snowfall reported by resorts was always exaggerated, but that phenomenon was even greater on the weekends.
weekday snow reports were less interesting to skiers than weekend reports.
snowfall reports were more common during weekends than weekdays, but this was even more true when there was fresh snow.
snowfall reports were exaggerated, and this was more pronounced for the weather reports provided by radio stations compared to resorts.
2.5 points
Question 20

A researcher is interested in whether circadian rhythms influence participants' performance on different kinds of memory tests. The researcher first classifies participants according to whether each is a morning person or evening person. The researcher then randomly assigns participants to receive either an implicit memory test or an explicit memory test. The researcher next tests everyone at 8 A.M. How many cells does this study have?
2
4
6
8
2.5 points
Question 21

The z, t, and F calculations have something in common: the numerator of the test statistic:
contains a measure of difference among groups.
contains a measure of sample variability.
is a squared number.
represents what would be expected to happen by chance.
2.5 points
Question 22

The assumptions for all ANOVAs are the same and include all of the following EXCEPT:
random selection of participants
population is normally distributed
population variances are equal
participants are all different across conditions
2.5 points
Question 23

________ is the proportion of variance in the dependent variable that is accounted for by the independent variable.
t
Cohen's d
R2
z
2.5 points
Question 24

According to Cohen's conventions, an effect size of 0.019 for a oneway withingroups ANOVA is considered to be:
small.
medium.
mediumtolarge.
large.
2.5 points
Question 25

Forys and Dahlquist (2007) investigated the effects of coping style and cognitive strategy on dealing with pain. Participants were first classified as having a monitoring or avoiding coping style. Participants were then randomly assigned to one of two cognitive strategy conditions, distraction or sensation monitoring. Participants were next instructed to use the cognitive strategy while submerging their hand in ice water. The researchers measured pain tolerance as the number of seconds participants were able to keep their hand in the ice water. How would you label the ANOVA used to analyze this data?
4 × 2 betweengroups ANOVA
4 × 2 withingroups ANOVA
2 × 2 betweengroups ANOVA
2 × 2 withingroups ANOVA
2.5 points
Question 26

Identify the correct formula for degrees of freedom betweengroups:
Ngroups – 1
n – 1
Ntotal – 1
n – 2
2.5 points
Question 27

A researcher is interested in whether circadian rhythms influence participants' performance on different kinds of memory tests. The researcher first classifies participants according to whether each is a morning person or an evening person. The researcher then randomly assigns participants to receive either an implicit memory test or an explicit memory test. The researcher then tests everyone at 8 A.M. How would you label the ANOVA used to analyze these data?
4 × 2 betweengroups ANOVA
4 × 2 withingroups ANOVA
2 × 2 betweengroups ANOVA
2 × 2 withingroups ANOVA
2.5 points
Question 28

A measure of the differences among group means is:
the z score.
betweengroups variance.
withingroups variance.
the proportionate reduction in error.
2.5 points
Question 29

An interaction occurs when:
the dependent variable does not depend on any of the independent variables.
two independent variables both influence the dependent variable.
the effects of one independent variable depend on the level of the other independent variable.
a single independent variable changes the dependent variable, disregarding all other variables in the study.
2.5 points
Question 30

F is obtained by dividing ________ by ________.
SSbetween; dfbetween
MSbetween; MSwithin
dfbetween; SSbetween
SSbetween; SSwithin
2.5 points
Question 31

In addition to assessing whether each independent variable has an effect on the dependent variable, a factorial ANOVA also allows you to:
use multiple dependent measures in a single analysis.
control for a third variable that might be related to the dependent measure, prior to investigating the independent variable of interest.
determine whether the effects of one factor depend on the other factor.
partition out the variability due to individual differences and the variability due to measurement error.
2.5 points
Question 32

Heteroscedastic populations are those that:
have the same variance.
have homogeneity of means.
share common means.
have different variances.
2.5 points
Question 33

According to Cohen's conventions, an effect size of 0.29 for a oneway withingroups ANOVA is considered to be:
small.
medium.
mediumtolarge.
large.
2.5 points
Question 34

An effect size of 0.015 for a twoway ANOVA is considered to be:
small.
medium.
large.
an error.
2.5 points
Question 35

If you calculate an F statistic and find that it is negative, then you know that:
the withingroups variance exceeds the betweengroups variance.
the difference among the group means is greater than what would have occurred by chance.
you have made a calculation error.
the difference among the group means is less than what would have occurred by chance.
2.5 points
Question 36

A boarding school (where students live and go to school) wants to find out if students’ scores on a Happiness Rating Scale change over the course of their first year. To this end, they administer the rating scale to students during the first week, and again at the end of the school year. Which type of ttest should the school staff use to test whether there is a significant change in happiness ratings?
ttest for independent means
onesample (single sample) ttest
ttest for dependent means
a combination of all 3.
2.5 points
Question 37

If the results of a twotailed ttest were to be presented in a research article, and there were 25 participants, what is the appropriate number in parentheses after the t?
t(25)
t(1)
t(2)
t(24)
2.5 points
Question 38

A community psychologist observes that children in a certain school tend to score lower on standardized math tests than students at other schools in the district. He knows that the mean scores of children in the district as a whole is 110. Which type of ttest should he use to determine whether the scores of the children in the school differ significantly from the scores in the school district overall?
ttest for independent means
onesample (single sample) ttest
ttest for dependent means
none of the above
2.5 points
Question 39

A psychologist publishes a paper based on a study and states that the results are significant at the .05 level. Based on this information, which of the following could be the p value of the results of the study?
.045
.4
.104
.06
2.5 points
Question 40
A social psychologist wants to test whether introverts and extroverts have different numbers of friends on a social networking site. She administers a personality test and, based on the results, divides the participants into 2 groups, Introverts and Extroverts. She then surveys the groups to find out how many friends they have recorded on the social networking site. Which type of ttest should she use to analyze the results?
ttest for independent means 

onesample (single sample) ttest 

ttest for dependent means 

It doesn’t matter, any of them should work. 
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