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Identifying Variables

Let's work on extraneous variables, confounding variables, and representative samples. Identify any confounding variable(s) in the following studies and comment about whether the sample is representative of the population of interest. Look for confounding variables that are obviously present in the study. . . . avoid speculating about items that are not mentioned.

A. You are studying the effects of wording of a survey question on response to the survey. You randomly assign 50 people to group A and 50 people to group B. You read a survey to group A; all of the questions include the word "not". Your assistant reads a survey to group B; all of the questions are the same but have been reworded to eliminate the word "not" (note that the meaning of the questions is exactly the same in both groups; just the wording is different). You compare the response to the survey between the two groups. The IV is wording of the survey questions and the DV is the score on the survey.

B. You want to know whether most people process information more easily when it is presented orally vs when it is presented in written form. The participants are students in a marching band course. You administer the same quiz twice to each participant; first the quiz administered orally; a week later the same quiz is administered in written form. You find that most people make fewer mistakes when the quiz was presented in written form. (The IV is the format of the quiz; the DV is score on the quiz.)

Solution Preview

Dear Student,
Hi and thank you for your trust. Before we tackle the scenarios below, let's discuss confounding variables first ( I think that in this 2-question set, this is the variable you are being asked to identify and to to discuss why they are such) so that you will be a little clear about them. What are they? Confounding variables are extraneous variables that correlate to both the dependent and independent variable. You must identify them clearly so that your study does not result into a false positive. They are are variables that while we deem them to be not of interest in our study, still affects the IV and DV that we have so that they affect our study and therefore 'confound' and 'muddy' the results which most of the time results to the failure of the study. The idea is to control the confounding variables. This is a kind of extraneous variable - they are there, they will affect the IV and DV although we usually find that they are of no initial interest to us in a study. Consider this. You are studying why people buy a certain brand of coffee. You assume that it is either the price or the ...

Solution Summary

The solution provides information, assistance and advise to students in tackling the problem (see above) on extraneous variables, confounding variables and representative samples in the 2 sample problems listed (A & B). Resources are included for further exploration of the topic.

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