Experimental design

• Aims- intention or research question, laying out what we intend to investigate, eg- whether tv or games impacts the quality of homework produced by students,
• Dependent variable- what we are going to measure,
• independent variable- what the experimenter manipulates, the experimental conditions (usually 2 but not always), the conditions are compared,
• hypothesis- a statement on what you expect you are going to find when conducting a study, states the relationship between the IV and the DV.
• Hypothesis eg- pps who complete a essay whilst watching a movie will get a lower mark than pps who are sat at a desk in a quiet room with no distractions.
• Directional hypothesis- will achieve a lower mark non directional- there will be a difference
• Experimental design refers to the way in which pps are arranged within diff experimental conditions, mp, ig, rm
• Independent groups, pps are split into 2 groups and each only experience one level of IV. The mean score of words spoken would then be compared.
• eg, g1 experiences condition A, g2 experiences condition B, indep groups
• Repeated measures- opposes indep groups where each group experience one condition, all pps here experience all levels of IV, and then the 2 mean scores from both conditions would be compared.
• Matched pairs- pps paired based on a trait relevant to the study then split into separate groups, eg iq in study, eg 2 highest iqs split into each condition and so on and so on,
• counterbalancing- used to counteract order effects.
• counterbalancing example- 50% of people experience condition A and then half experience condition b, then both sides switch, the purpose of this is that half of the groups are partaking in each variable for the first time,
• RM- order effects can impact the results, tasks completed in one condition, could have an affect on the task completed in another. demand characteristics may be an issue as people cannot work out the aim of the study.
• RM design pros- pp variables are being controlled because rhe same pps are in both conditions, more economical than indep groups or matched pairs as half the amount of pps are needed.