Experimental Designs

Question 1

Name 3 Experimental Designs

Answer 1

Independent Groups
Repeated Measures
Matched Pairs

Question 2

Independent Groups A01

Answer 2

One group does condition A, other does B , Participants should be randomly allocated to groups

Question 2

Independent Strength

Answer 2

No order effects, participants only tested once no boredom, tiredness or practice effect, controls important CV

Question 3

Independent Weakness

Answer 3

Less economical, need twice as many participants expensive and time consuming

Question 4

Repeated measures A01

Answer 4

Same participants take part in all conditions of an experiment.
The order of conditions should be counterbalanced to avoid order effects.

Question 5

Repeated measure’s strength

Answer 5

+ participant variables.
The person in both conditions has the same characteristics.
This controls an important CV.

Question 5

Repeated measures weakness

Answer 5

• order effects are a problem.
  Participants may do better or worse when doing a similar task twice. Also practice/fatigue effects.
  Reduces validity of results.

Question 6

Matched pairs A01

Answer 6

Two groups of participants are used but they are also related to each other by being paired on participant variable(s) that matter for the experiment.

Question 7

Matched pairs strengths

Answer 7

+ no order effects
Participants are only tested once so no practice or fatigue effects.
This enhances the validity of the results.

Question 8

Matched pairs weakness

Answer 8

• matching is not perfect
  Matching is time-consuming and can’t control all relevant variables.
  Cannot address all participant variables.