1. AS Psychology Research Methods
Case Studies, Observations, and Correlations

2. Case Studies
A case study is an idiographic, in-depth study of an individual or small group. Sometimes data from one individual can challenge established theories.
Strengths – participants are often studied over a period of time, so developmental changes can be recorded. This is longitudinal, and often means very detailed data.
Weaknesses – because case studies sometimes involve quite an intense relationship between the researcher and participant, the researcher may lack objectivity. There might be only one participant (or very few) involved, and so any conclusions cannot be generalized to others. It is difficult to replicate.

3. Observations
Naturalistic – observing behavior in a natural environment, school or workplace, without researcher interference.
Strengths – higher in ecological validity, quantitative data which is more objective, can be used in situations where manipulation of IV would be unethical, less demand characteristics, and may act more normally.
Weaknesses – little control over variables, cannot conclude cause and effect relationship, observer bias, hard to replicate, hard to check inter- and intra-rater reliability, and ethics (if they don’t know they’re being observed).

4. Observations (Cont’d)
Controlled – watching the participants in a manipulated situation. The environment could be either normal or artificial.
Strengths – some confounding variables are controlled.
Weaknesses – behavior may not be natural, observer bias, and the participants might differ their behavior if they know they’re being watched.

5. Observations (Cont’d)
Participant – the observer interacts with the observed.
Strengths – easier to understand the person’s behavior and high in ecological validity.
Weaknesses – observations done retrospectively (unreliable), observer can become too involved and data can be subjective, and observer bias.

6. Observations (Cont’d)
Non-Participant – the researcher does not become involved in the situation. Ex: watches through a one-way mirror.
Strengths – observations made as they happen and observer can remain objective.
Weaknesses – the meaning behind the behavior may be unknown and observer bias.

7. Observations (Cont’d)
Overt – the role of the observer is obvious to the participants.
Covert – the role of the observer is not obvious since they are hidden or disguised.

8. Correlations
Correlation is a research method which investigates the strength of the relationship between two variables. The strength is expressed as the correlation coefficient (a number between -1 and +1).
Positive Correlation means the relationship between two variables in which an increase in one accompanies an increase in the other.
Negative Correlation means the relationship between two variables in which an increase in one accompanies a decrease in the other.

9. Correlations (Cont’d)
Strengths – it allows researchers to analyze a relationship between variables that cannot be experimentally manipulated. Allows predictions to be made.
Weaknesses – does not show a cause and effect relationship and there can be extraneous influencing factors.