experimental designs- research methods

Question 1

independent groups

Answer 1

two separate groups of pps experience two differnet conditions of experiment
performance will be compared

Question 2

repeated measures

Answer 2

all pps experience both conditions of experiment
two means scores from both conditions compared to see a difference

Question 3

matched pairs

Answer 3

pps paired together on variable or variables relevant to the experiment
one pps from each pair allocated to different condition of experiment
attempt to control confounding variables of pps variables

Question 4

independent groups eval

Answer 4

• pps who occupy different groups not the same in terms of pps variables, if research finds mean difference between groups on dv this may be more to do with pps variables than the effects of the iv, differences may act as confounding variable reducing validity, to dela with this researchers use random allocation
• less economical than repeated measures, need twice as many pps to produce equivalent data than that of repeatewd measures, increases money and time on recruiting pps
  + order effects not prpoblem but problem for repeated meaures, pps less likely to guess the aims

Question 5

repeated measures eval

Answer 5

• each pps has to do at least two tasks and order of these tasks may be significatn, researchers use counterbalancing to reduce this
• order effects, two tasks could create bordom or fatigue that might cause deterioration in performance, confounding variable
• work out aim of study when they experience all conditions of the experiment, demand characteristics feature
  + pps variables controlled and fewer pps are needed less time recruiting them

Question 6

matched pairs eval

Answer 6

+ pps only take part in single condition so order effects and demand characteristics less of problem
- pps can never be matced exactly, important differences that may affect dv
- time consuming and expensive, less economical than other designs

Question 7

counterbalancing

Answer 7

attempt to control order effects
half pps take part in condition a then b and the other half take part in b then a
ABBA
does not remove or prevent problem but attempts to balance out effects