Experimental designs

Question 1

Repeated Measures design

Answer 1

Participants take part in both conditions of the IV (both lvls of IV)

Question 2

A03 - Strengths of repeated measures

Answer 2

Pps are the same so you have no differences between people –> reduced participant variable. e.g. IQ

Question 3

A03 - Weakness of Repeated measures

Answer 3

Order of the conditions may affect performance - “order effects” (confounding variable)
1. Practice effect (do better in cond 2 as learned from 1)
2. Fatigue effect (boredom, fatigue)
3. Increase in demand characteristics

They are the different effects not a list

Question 4

How to deal with order effects

Answer 4

Counterbalancing - order in which the conditions are encountered are BALANCED out
* con A = real words con B = nonsense words
* AB or BA (then you can allocate which group does which)
* Half of the pps experience the conditions in one order while the other in the opposite

Question 5

Independent groups

Answer 5

Pps are randomly allocated to one condition of the IV. One group undergoes one condition and the other group undergoes the other.

Question 6

A03 - strengths of Independent groups

Answer 6

• No order effects - only done it once
• same materials can be used in cond A+B - meaning a test (e.g. word list) does not need to be standardised/assessed for lvl of difficulty.
• reduced demand characteristics

Question 7

A03 - Weakness of independent groups

Answer 7

Researcher cannot control the effects of participant variables
* individual differences - e.g. IQ
* Ps in cond A may be different to those in cond B

Question 8

Solution to independent groups

Answer 8

Random allocation - Ps can be allocated to diff groups to ensure an even spread of the participants characteristics
* e.g. done by hat/online randomiser

Question 9

Matched pairs

Answer 9

Pps are matched based on similarities or key characteristics
e.g. similar age, gender, IQ
* believed to have an influence on the DV
* The pps pairings will be then allocated to diff conditions (in attempt) to control confounding variable of participant variables

Question 10

A03 - Strengths of matched pairs

Answer 10

Reduce the num of participant variables (IQ, age, gender, memory test)

Question 11

A03 - weakness of matched pairs

Answer 11

Difficult to reduce all the participant variables, have differences unbeknown to the researcher