PSY 550 FINAL EXAM: RESEARCH METHODS . QUESTIONS AND ANSWERS. (LATEST) A+ GRADED.Instructions: This is an open-book and open-notes exam. You have 2 hours t... [Show More] o complete the exam. The test is worth 100 points; each item is worth 10 points.
1. Chuck Wagon is very excited about the within-subjects approach. “Now I’ll never need to run large numbers of subjects again,” he says. However, Chuck has forgotten that within-subjects designs may be a) useless, b) impossible, c) confounded by order effects, or d) impractical when excessive subject time spent in an experiment makes data inaccurate. Give an example of each of these four objections.
a) useless - imagine you want to assess the effectiveness of two educational programs in teaching children to read. Now you could have a child complete both of the programs, but since they've already learned to read after completing the first one (or at least improved their skills considerably), having them complete the second one would tell us absolutely nothing about its effectiveness.
b) impossible - say you want to study the effect of gender on consumer behavior. In this case, gender is the independent variable with two conditions (male and female). Assuming a person cannot complete both conditions (i.e. be male and female), you can't run a within-subjects design. Age or expertise would be other examples where one person cannot complete all conditions (except maybe if you're running a longitudinal study).
c) confounded by order effects - Practice and fatigue are common order effects. Usually, these can be managed with counter-balancing (changing the order of the conditions for different participants) but sometimes, that may not be possible. Maybe you want to test people's performance at playing the piano, with and without having been given some tips on how to do it. If you let them do it without the tips first, then give them the tips and let them do it again, you don't know if the effects are the result of the tips or simply practice. You also can't change the order of the two conditions because people cannot unlearn the tips you've given them.
d) impractical when excessive subject time spent in an experiment makes data inaccurate - when you have a lot of conditions, the time of the experiment can become too long for the participants to handle. For example, maybe you want participants to watch a 10-minute advertisement and then test their willingness to buy the product advertised. You have 20 of such advertisements altogether. If you make your participants watch all of them, they may become fatigued long before the end of the experiment and no longer pay attention to the advertisements. Even if you counter-balance, you still lose a lot of valuable data from each participant. Longer time spans also increase the risk that participants will drop out of the study altogether.
2. Explain the pros and cons of longitudinal, cross-sectional, and sequential designs.
Longitudinal Pros: Shows developmental course, continuity and discontinuity, eliminates cohort. Cons, they are expensive, long, practice effect and selective attribution.
Cross-sectional Pros: quick, cheap, demonstrates age difference. Cons; Cohort effect, doesn’t show development process and doesn’t show if its continuous or discontinuous.
Sequential Pros; can compare cohorts, not to expensive. Cons: Complicated
3. After watching nursery-school children, Ken Garoo wants to test the hypothesis that some toys are more fun to play with than others. He decides to compare “fun” toys (blocks) with “unfun” toys (stuffed animals). He also wishes to see if there is a sex difference, as well, so sex is added as an independent variable. A) What kind of design is needed? B) Diagram it out. C) Assuming 20 subjects are needed per cell, how many subjects are needed for this study?
A) IVs - gender (male vs female); toy type (fun vs unfun). DV - how fun the child finds playing with the toy to be. I'll assume both variables are between-subjects i.e. each child plays with only one toy - either the fun or the unfun one (and children are either male or female, obviously [Show Less]