# Discussion question response

*label*Business

*timer*Asked: Oct 28th, 2014

**Question description**

I need a follow up response to one of the discussion questions. Here is the answer I provided.

**What are the four major sources of measurement error? Illustrate by example how each of these might affect measurement results in a face-to-face interview situation.**

The major reason for the errors that occur in measurement are the difference in information desired and difference in the information provided. The major four type of error are as follows:

**Experimental error:** This kind of error occurs while measuring the experiment than the independent variable. For instance if we need to understand the impact of price change in a store and analyze the political and other factors that hinder the price it will result in experimental error.

**Population error:** This type of error occurs when the population selected for the data collection is not appropriate. Suppose if a company that wants to determine the criteria followed for the purchase of a toll and does it among the purchasing agents alone then it will lead to population error.

**Sampling error:** This type of error is observed when non-representative samples are generated by means of probability. It is major error in the classical statistics.

**Selection Error:** This is a major problem in the non probability sampling methods that arise due to the occurrence of non representative samples. This will result in error in the survey result.

Can you elaborate on your explanations for Sampling and Selection error? Are these the same type of error? What is the significance of probability non-probality sampling?