Controls For Experimental Methods And Designs

Question 1

What are the two problems that need controlling in experimental methods?

Answer 1

Demand characteristics and bias

Question 2

What are demand characteristics and how can they be controlled?

Answer 2

• demand characteristics are when clues given off lead to ppts changing nat bhv to help researcher, reducing int val but only if experimenter is aware of aims of study
• they can be controlled by getting another researcher who doesnt know aims of research to carry out experiments, therefore they cant give off clues to influence ppts

Question 3

What is meant by bias in research and what are the two ways it can be controlled?

Answer 3

• bias in research occurs when researcher is designing exp or collecting results
• can be controlled by randomisation and standardisation

Question 4

Why should randomisation take place and how?

Answer 4

• aspects of research should be random and not decided by researcher so its not open to bias or bringing in extraneous variables
• all items should be put in a hat
• draw out as many needed for condition 1
• draw out as many needed for condition 2

Question 5

Why should standardisation take place and how?

Answer 5

• important that all ppts experience same env and intructions to avoid extraneous variables affecting DV
• use same standardised instructions either read out or given to ppts, procedures for all ppts and match difficulty elements in tasks

Question 6

What is the problem with an independent groups design and why and how should it be controlled?

Answer 6

• indv differences can be controlled using random allocation
• this ensures each ppt has the same chance of being in any of the conditions, therefore it is unlikely all ppts in one condition will share a characteristic to help them perform better at DV
• write names of the ppts on equal sized pieces of paper
• put in hat and mix
• randomly pick out ppts names and place half in condition 1 and other half in condition 2

Question 7

What is the problem with a repeated measures design and why and how should it be controlled?

Answer 7

• order effects can be controlled by counterbalancing
• to control and reduce order effects
• half of ppts complete condition A and then then condition B
• the other half should complete condition B first then condition A
• order effects are now balanced across both conditions