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
Substance use
Time of day
Time allowed to learn material
Tiredness
Ability of learner
Stress
Other information
Gender
Old memories
Noise levels
Hunger
Educational opportunities

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

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

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

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?
EXTRANEOUS
VARIABLES
CONTROLLED
VARIABLES
Caffeine intake IV
Age
Time of day
Tiredness
Time allowed to learn material
No. of words remembered DV
Ability of learner
Other information
Stress
Old memories
CONFOUNDING VARIABLE
Educational opportunities
Hunger
Noise levels
Gender