PSY550 Final Exam: Research Methods
Instructions: This is an open-book and open-notes exam. You have 2 hours to complete the exam. The test is worth
... [Show More] 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.
Answer:
a). useless- a within-subjects design would be useless if we were studying the effectiveness of two learning programs (reading for instance). If a student completed one program to learn how to read, it would be useless for them to complete the other program as they already gained the skills in the first program, and thus could not truly test the effectiveness of the second program.
b). impossible- a within-subjects design is impossible when you fail to find a sample that is representative of the population. For instance, if gender is a variable (independent variable), a participant cannot be both male and female, and thus it is impossible to measure within-subjects.
c). confounded by order effects- If you were to provide tips or suggestions on how to play an instrument to see if they improve over prior to the tips, but there is no way to know if improvement in the skill came from the tips provided or from practicing the instrument. The order of the conditions cannot be changed as the participants cannot unlearn the tips that were provided to them.
d). impractical when excessive subject time spent in an experiment makes data inaccurate- If too many conditions are presented to participants, or conditions are presented for excessive lengths of time, participants are likely to become fatigued or even drop out of the study. If a participant becomes fatigued, they are less likely to be able to pay attention to the conditions and thus, likely to not provide accurate information to the research.
2. Explain the pros and cons of longitudinal, cross-sectional, and sequential designs.
Answer:
-Longitudinal design is defined in our text as a developmental research design that is utilized to study the changes of its participants across a life span. This is done by observing the same set of participants and different points in time, and measuring the same dependent variable at each point in time (Privitera, 2017). A pro to this is the ability to learn a developmental course through continuity and it eliminates cohort. A con to this design si that these are usually costly designs, they take a long time, participants can drop out or pass. Additionally, long term research increases the chances of unpredictable outcomes.
-Cross-sectional design is defined in our text as a developmental research design in which participants are grouped by their age and participant characteristics are measured in each age group (Privitera, 2017). Pros of this design are the low cost and speed of study, the ability to prove or disprove assumptions and multiple variables are viewed at the time of the data snapshot. Cons of this design study are that they cannot be used to analyze behaviors, they are useless for determining cause and effect and they cannot show any developmental progress.
-Sequential design is defined in our text as a developmental research design that combines longitudinal and cross-sectional techniques by observing different cohorts of participants over [Show Less]