Research Design

Validity Validity refers to the amount that a measure actually measures the concept it is designed to measure

Reliability Reliability is related but refers to the consistency of a measure – does it consistently measure the concept This could look like test-retest reliability, inter-rater reliability, or internal consistency (in other words are you lying/malingering) (the same test repeated, consistency across different observers, multiple items related to the same concept to see if the responder answers in similar ways

Meta-analysis

Remember… Representative samples are better than biased samples You want to be confident that there is not some third factor Less variable observations are more reliable than those that are more variable – hence our focus on standard deviations More cases are better than fewer Statistical significance is not the same thing as importance

Cross-sectional research Different groups of varying ages to assess behaviours associated with age Cheaper, snapshot in time but must beware of cohort effects

Longitudinal A group of individuals is observed for a long period of time It is expensive, time-consuming and prey to people dropping out (dying)

Mixed longitudinal Participants from a range of ages are observed for a limited time, ex. 5 years It is less expensive and avoids some of the cohort effect

Tuskegee https://www.youtube.com/watch?v=9Rg75zEVB1g https://www.youtube.com/watch?v=BQOD8KIfBu0 https://www.history.com/news/the-infamous-40-year-tuskegee- study (read for more information)

Let’s discuss… 1. Most people's initial reaction to the Tuskegee experiment is to ask how it could have happened. What do you think? Could it happen again? 2. Some groups have a history of being exploited by medical researchers; others (e.g., women) of being left out; some of both. To what extent should research take into account differences among human beings? For instance, should they assume people are basically alike, and not actively seek out differences? What represents best practice? Other thoughts you have…

Practice designing a study: Jumping off points Drug A makes children more attentive in school Increased social connections is beneficial for reducing anxiety and depression The larger the family, the duller the children are Moderate levels of exercise are beneficial for cognition Television violence is related to aggression in children Absence makes the heart grow fonder Design a study that allows you to investigate one of these topics.

Ethics and the Robber’s Cave What methodological issues do you notice?  What would you change if you were to replicate the study? In your opinion, how generalizable are the results of the study? How are ethical considerations addressed? What are the implications for further research? Ethics and the Robber’s Cave

Explain the structure of your research (case-study, experiment, correlational research (longitudinal, cross-sectional, mixed-longitudinal) etc. Outline the participants you expect to include and how you will recruit them Detail your hypothesis, independent variable, dependent variable, controlled variables (anticipate confounding variables) Explain the methods you will use and your reasons Instead of results, explain what you anticipate the results to be and be sure to explain how you will deal with the data you would collect Address ethical concerns Address the generalizability of the results and how your research can be applied Design a study