1. Research Methods in Psychology

2. There are a number of methods used in Psychology to study people Laboratory Experiments Field Experiments Natural Experiments Self report: Interviews Self report: Questionnaires Observations Case studies Correlations

3. Experiments We need to understand some terminology before we understand the three types of experiments Independent Variable (IV) Dependent Variable (DV) Extraneous (Confounding) Variables Controlled Variables

4. What factors can affect memory? Age Tiredness Substance use Stress Noise levels Other information Old memories Time allowed to learn material Ability of learner Time of day Hunger Gender Educational opportunities

5. We want to study… … Does caffeine affect memory?

6. What factors can affect memory? Age Tiredness Substance use Stress Noise levels Other information Old memories Time allowed to learn material Ability of learner Time of day Hunger Gender Educational opportunities

7. The Independent Variable To see whether Caffeine affects people’s ability to remember things, we need to isolate that variable from all the other variables This is to make sure that if we have a difference in memory scores between two groups, this difference is only due to caffeine intake, and not other variables, such as noise in the room, the age of the participant, the cognitive ability of the participant etc.

8. Age Tiredness Substance use Stress Noise levels Other information Old memories Time allowed to learn material Ability of learner Time of day Hunger Gender Educational opportunities This is the Independent Variable – It is Independent from all other variables We need to control these variables so that they do not affect the results

9. Operationalized Variables In our example, we are studying the effects of caffeine on memory, but we need to be specific about the Independent Variable so that people can test the reliability of the study, and also to stop false conclusions being drawn So our operationalized Independent variable would be… People who are given 30 mgs of Caffeine 30 minutes before the memory test, and people who are given 0 mgs of caffeine before the memory test.

10. The Dependent Variable This is the behaviour that is being measured In our example, it is memory. But we need to be more specific. In our experiment, we will test how many words the participants can remember from a list of 30 single syllable words We are predicting that memory ability will be dependent on whether the participants have caffeine or not

11. Our Hypothesis Caffeine affects memory There will be a difference in how many words the participants can remember from a list of 30 single syllable words between people who are given 30 mgs of Caffeine 30 minutes before the memory test, and people who are given 0 mgs of caffeine 30 minutes before the memory test. It’s long winded – but operationalized and replicable TOO BASIC

12. What factors can affect memory? Age Tiredness Substance use Stress Noise levels Other information Old memories Time allowed to learn material Ability of learner Time of day Hunger Gender Educational opportunities No. of words remembered DV IV EXTRANEOUS VARIABLES Caffeine intake

13. When extraneous variables are controlled by the experimenter, they are called controlled variables When extraneous variables are not controlled and influence the DV, they become confounding variables

14. What factors can affect memory? Age Tiredness Stress Noise levels Other information Old memories Time allowed to learn material Ability of learner Time of day Hunger Gender Educational opportunities No. of words rememberedDV IV EXTRANEOUS VARIABLES Caffeine intake CONFOUNDING VARIABLE CONTROLLED VARIABLES