experimental designs

Question 1

what is counterbalancing and why does it work?

Answer 1

• it is an attempt to control order effects
• half the participants do condition A then B, other half do B then A
• balances out order effects and increases validity

Question 2

what is random allocation to conditions and why does it work?

Answer 2

• addresses the issue of participant variables
• evenly distributes characteristics across conditions by using random techniques
• eg. out of a hat, random number generator

Question 3

independent groups

Answer 3

definition - different groups of participants take part in each condition of the experiment

strengths - order effects are not a problem, participants are less likely to guess the aim of the study

limitations - participants aren’t the same in terms of participant variables, reduces validity, more participants are needed, increased use of time and money

Question 4

repeated measures

Answer 4

definition - all participants take part in all conditions of experiment

strengths - variables are controlled, higher validity, fewer participants are needed

limitations - order effects are likely, doing more than 2 tasks may cause boredom or fatigue, more likely that participants will guess the aim of the study

Question 5

matched pairs

Answer 5

definition - pairs of participants matched on a variable that may affect DV, one of each pair does condition A and other does B

strengths - only one condition so order effects and demand characteristics aren’t an issue

limitations - participants can never be matched exactly, can be expensive and time-consuming