Experimental Design Flashcards
What is the scientific process?
- Aim
- Hypothesis
- Method
- Results
- Conclusion
What are researcher aims?
Aims are the general statement of what the researcher intends to investigate; the purpose of the study.
What is a hypothesis?
A hypothesis is a prediction about the relationship between variables that are being studied.
What are the two types of hypotheses?
Directional hypothesis
Non-directional hypothesis
What does operationalisation mean?
clearly defining variables in terms of how they can be measured
What are the different types of experimental design?
Independent groups design
Repeated measures design
Matched pairs design
What is an independent groups design?
uses different participants in each of the experimental conditions, so that each participant only does one
condition
What are some strengths for independent groups?
There are no order effects whereby the order in which the conditions are done may have an effect on the outcome.
Participants do one condition each, therefore there is less chance that they can guess the purpose of the study and act accordingly.
Both sets of participants can be tested at the same time, saving time and effort.
What are some limitations for independent groups?
With participants each doing only one condition, twice as many participants as needed as for a repeated measures design.
Differences in results between the two conditions may be due to participant variables rather than manipulation of the IV.
What is a repeated measures design?
each participant is tested in all conditions of an experiment. Participants are therefore being tested against
themselves.
What are some strengths repeated measures design?
The same people are measured in all conditions, there are no participant variables between the conditions.
Each participant produces two or more scores, more data is produced compared with an independent measures design, fewer participants are needed to get the same amount of data.
What are some limitations for a repeated measures design?
By participating in all conditions, it is more likely that participants may guess the purpose of the study and act accordingly.
A gap may be needed between conditions to counter the effects of fatigue or boredom.
What is a matched pairs design?
participants are matched on characteristics important for a particular study.
What are some strengths of a matched pairs design?
As different participants do each condition there are no order effects.
Participants do one condition each, therefore there is less chance of them guessing the purpose of the study.
As participants are matched, there should be less chance of participant variables affecting the results.
What are some limitations of a matched pairs design?
With participants each doing only one condition, more participants are needed than for an RMD.
It is a lengthy process to match participants.
It is impossible to match all variables between participants and an unmatched variable might be vitally important.
