topic 12 research methods Flashcards
what is an independent groups design?
different participants are used in each condition of the study.
what are the advantages of independent groups design?
-demand characteristics are less of a problem as each person only takes part in one condition. therefore, they’re less likely to guess the aim of the study and behave differently
- no ‘order effects;:prior learning (the practice effect) or boredom (the fatigue effect) do not affect performance as each participant does one condition
what are the disadvantages of independent groups design?
-differences in results between two conditions may be due to participant variables and not the IV. so its hard to establish cause and effect.
-more pp’s are needed than a repeated measures design because each participant is used only once. therefore more time consuming for the researcher to gain their sample.
what is the control for independent groups design?
random allocation - reduces the impact of researcher bias/participant variables. (e.g. putting names in a hat)
what are repeated measures?
the same participants take part in both conditions of the study
what are the advantages of repeated measures?
- participant variables kept constant between two conditions as the same people are used
- fewer pp’s needed, than independent groups design to get same amount of data
what are the disadvantages of repeated measures?
-demand characteristics may become a problem, as pp’s do both conditions and increases chance of working out the aim and changing their behaviour
-order effects such as prior learning (practice effect), boredom/tiredness (fatigue effect) can affect performance in the second task when one condition is done after another.
what is the control for repeated measures?
counterbalancing - reduces the impacts of order effects. half of the pp’s do condition A followed by condition B and the other half start with condition B and then complete condition A. this is known as the ABBA technique and it prevents CV’s
what are matched pairs?
each participant takes part in one condition of the study, but they are matched on some criteria that matters to the study in question with someone in the other condition. this is created by participant variables (e.g. gender, age or a preliminary test such as a memory test). once pairs are allocated, they are randomly assigned either condition A or B.
what are the advantages of matched pairs?
- participant variables are minimised between two conditions due to the matching process
-demand characteristics are less likely with this design as the pp only takes part in one condition
-results are not affected by order effects as the pp takes part in one condition
what are the disadvantages of matched pairs?
- there can be matching difficulties. pp variables can never be matched perfectly.
- time consuming - lengthy process to match participants because each pp is used in only one study.
