Experimental Design

Question 1

what is an independent measures design?

Answer 1

where different participants are placed in different conditions of the experiment

Question 2

3 strengths of independent measures

Answer 2

1. order effects like learning/fatigue don’t influence second condition as subjects only in one condition
2. demand characteristics reduced as only in one condition so naive to test and less likely to guess aims and act differently
3. same test can be used for each condition (e.g. memory test)

Question 3

3 weakness of independent measures

Answer 3

1. subjct variables differ so independent difference coud become CVs unless controlled for
2. worse stats tests as more variation between conditions
3. more subjects required so less economical

Question 4

what is a repeated measures design?

Answer 4

involves using the same subjects for each condition of an experiment

Question 5

3 strengths of a repeated measures design?

Answer 5

1. individual differences which could be EVs are kept constant between conditions
2. better stats tests can be done as less variatino between conditions
3. fewer subjects required so more economical

Question 6

2 weaknesses of repeated measures

Answer 6

1. order effects like learning or fatigue may affect results as change participants’ behaviour in subsequent conditions
2. demand conditions may affect results as sam Ps in each condition so may guess aim so act differently

Question 7

what is a matched pairs design?

Answer 7

where different participants are used in each condition, but they are matched on important characteristics that may affect their performance

Question 8

5 strengths of matched pairs

Answer 8

1. independent variables kept more constant between conditions
2. bettwer stats tests can be done as less variation
3. order effects don’t occur as each P only in one condition
4. demand characteristics reduced as Ps ony in one condition
5. same test ca be used

Question 9

what is random allocation

Answer 9

Ps randomly assigned to each experimental condition to distribute them evenly across conditions using random techniques

Question 10

what is random allocation used for?

Answer 10

attempts to address issue of independent variables in independent groups design

Question 11

what is couonterbalancing?

Answer 11

1/2 Ps does condition A then condition B and other 1/2 does condition B then condition A

Question 12

why is counterbalancing used

Answer 12

attempts to control order effects in repeated measures design