- Validity concers discovering what is real/genuine. Ecological validity concerns being able to generalise research findings behind a particular research setting. Internal validty concers whether a researcher is measuring what was intended to be measured.
- Reliability concerns the consistency of a study.
Hypothesis and aims.
- A hypothesis is a statement o what the researcherbelieves to be true.
- A hypothesis must be operationalised before a researcher can conduct a study to test the hypothesis.
- A directional hypothesis state whether changes are greater/lesser, positive or negative etc.
- A non-directional hypothesis doesn't state the direction.
- The aims of a study are a general statementof intention.
The experimental method.
- Description: Must have a independent variable (IV) and a dependent variable (DV). The IV will be manipulated. The DV is assessed. There are levels of the IV, e.g in Loftus study the levels were the verbs:hit, contacted, bumped, smashed, collided.
- Strengths: The deliberate manipulation of the IV means casual relationships can be investigated.
- Limitations: The limitations of the experimental method vary depending on the type of experiment.
- Description: A labatory is a special environment where casual relationships can be investigated under controlled conditons. EV's can be controlled. The importance of controlled conditions in a lab experiment is: 1) to control the IV. 2. Control extraneous variables (such as experimenter effects, things like the amount of lighting/ heat/ etc.
- Strengths: Ev's can be controlled. Lab experiements easily replicated.
- Limitations: Lab experiements are artificial. Experimenter effects may influence the results. Demand characteristics may be a problem.
- Description: More natural environement,less controlled. IV controlled but less so EVs.
- Strengths: One strength is that there is greater ecological validity. Participants are not usually aware that theirbehaviour is being studied.
- Limitations: More difficult to control EV's. There are ethical issues (not given opportunity to provide informed consent beorehand and are usually not debriefed at end of study, possible invasion of privacy).
- Description: Experimenter doesn't mainupulate the IV. DV may be assessed in the natural environment or in a laboratory.
- Strengths: Enables behaviours to be studied where manipulation would not be possible. Greater ecological validity.
- Limitations: natural experiments do not demonstrate a casual relationship. There is less control of EVs than in a lab experiment.
Independent groups design
- Description: one group of people do conditon A and a second group do condition B. Random allocation is used to assign participants to groups.
- Strengths: Method avoids the limitations of using a repeated measures design, e.g there are no order effects. There is less of a problem with participants guessing the aims of the study.
- Limitations: The participant variables may act as EVs. More participants needed than for repeated measures design.
Repeated measures design
- Description: Each participant does all conditions, i.e is tested again. The order in which participants are tested may vary to avoid order effects.
- Strengths: One strength is that this controls participant variables. Fewer participants are needed than for independent groups deisgn.
- Limitations: Order effects can be a…