Experimental design

Question 1

3 types of experimental design are?

Answer 1

independent groups, Repeated measures, matched pairs

Question 2

Independent groups

Answer 2

ppts take part in one condition only. each condition has a different group of ppts

Question 3

repeated measures

Answer 3

all ppts take part in all conditions of the experiment

Question 4

matched pairs

Answer 4

ppts are matched on important characteristics e.g. age or IQ. each member of the pair is then split across each condition

Question 5

Independent groups +

Answer 5

conditions which may lead em to become bored or better at task
- can be used when repeated measures is inappropriate (e.g. quasi - gender diff) as each condition needs diff ppts

Question 6

independent groups -

Answer 6

• ppt variables may affect the DV as seperate groups of ppts in each condition
• more ppts needed as 2 difff groups are required UNLIKE repeated where u use less as ppts take part in both conditions

Question 7

repeated measures +

Answer 7

• ppt variables between pts are removed e.g IQ as potential confounding variables as ppts take part in all conditions increasing the internal validity
• increases the no. of ppts in each condition as the same ppts take part in all conditions UNLIKE in IDEPENDENT group design. this may increase population validity

Question 8

repeated measures -

Answer 8

• increased chance of demand characteristics as ppts take part in all conditions and may pick up on clues changing their bhvr to help or hinder research lowering internal validity
• order effects may occur when ppts take part in more than one experimental condition they may become bored or better at the task lowering internal validity

Question 9

matched pairs +

Answer 9

• controls the ppt variables of ppts such as matching ppts on IQ unlike in an independent measures (twins are ideal)
• there will be no order effects as ppts only do one con so they will not get bored or better at the task UNLIKE IN a repeated measures design

Question 10

matched pairs -

Answer 10

• very time consuming to match up and would need similar ppts - need a very large pool of ppl UNLIKE repeated measures where same ppts used 2x
• diff to completely match ppts on imprt characteristics, so ppt variable may stil; have an effect