OCR AS Psychological Investigations

Self Report: Often Questionnaires and interviews.

Advantages: Allows us to get an insight into the participants thoughts and opinions. 

Disadvantages: Some participants may lie and give untrue answers due to social desirability. 

Observation: Participants behvaviours are observed.

Advantages: Often high in ecological validity as the observations take place in a natural settings and participants are often unaware that they are being observed. 

Disadvantages: Lack of control may cause an observation to be difficult. (Extraneous Variables) Making it difficult for all behavours to be observed and recorded. 

Correlation: This investigates possible relationships between variables. 

Advantages: Can demonstrate a possible relationship between variables.

Disadvantages: Does not establish cause and effect. 

Lab Experiment:  An experiment conducted under controlled conditions. The variable that is being manipulated is called the independent variable (IV) and the variable that is being measures is called the dependent variable (DV). 

 Advantages: Allows precise control of varibales and ensure that all extraneous varibales are accounted for allowing us to conclude that the IV is affecting the DV and that nothing else is the cause. 

Disadvantages: Too much control can cause the condtions to be artificial causing lab experiments to be low in ecological validity. Also demand characteristics is often a problem as participants may behave in a way that they think is expected of them. 

Field experiment: This is an experiment that is conducted in a real life situation. 

Advantages: High in ecological validity and avoids demand characteristics as participants are usually unaware that they are taking part.

Disadvantages: Hard to control other variables that may affect the experiment. (Extraneous variables)

Quasi Experiment: This is where the IV is naturally occurring and is not manipulated by the researcher. 

Advantages: High in ecological validity. Not as artificial as Lab experiments.

Disadvantages: Hard to establish a relationship between variables as the IV is not being directly manipulated by the researcher. 

Independent measures design: This is where different participants take part in all conditions. 

Advantages: There will be no carry over or order effects.

Disadvantages: There may be individual differences between the different participants taking part in all conditions.

Repeated Measures Design: This is where the same participants takes part in all conditions.

Advantages: Potential individual differences between participants will be removed.

Disadvantages: There may be carry over or order effects.

Matched Pairs Design: This uses different participants for each condition but participants are matched on characteristics such as gender. 

Advantages: Potential individual differences between participants are accounted for.

Disadvantages: Difficult and time consuming. 

A hypotheses is a testable, predictive statement. When creating a hypotheses it is important to state the IV and the DV. You may also gain more marks by stating how the IV will be manipulated and how the DV will be measured. 

Alternate hypotheses: This predicts that there will be a significant difference. 

One Tailed Hypotheses: This is a hypotheses that states and predicts the direction of the results. E.G. Girls will do significantly better on a memory test than boys. 

Two Tailed Hypotheses: This hypotheses does not predict the direction of the results. E.G: There will be a significant difference on the performance on a memory test between boys and girls. 

Null Hypotheses: This states that there will not be a significant difference. E.G. There will be no significant difference on the performance on a memory test between boys and girls.