RM (Experiments) - Controls: random allocation and standardisation, random allocation and counterbalancing

Question 1

Why do we need controls?

Answer 1

• bias in research
• when researcher is designing resources/experiments
• or collecting results
• e.g. sample bias, research bias

Question 2

Why is randomisation used?

Answer 2

• research should be random/by chance where possible
• not decided by researcher (open to bias)
• could present extraneous variables

Question 3

How is randomisation carried out?

Answer 3

• order of conditions should be randomly decided
• e.g. order of list of words randomly generated
• out of hat/computer

Question 4

Why is standardisation used?

Answer 4

• all ppts
• same environment
• same instructions
• avoids extraneous variables affecting measurements

Question 5

How is standardisation carried out?

Answer 5

• all ppts get same standardised instructions and procedures (CONTEXT)
• instructions read out/given to all ppts

Question 6

What is the problem with independent groups design? Explain why

Answer 6

• individual differences
• different ppts in each condition
• one group may have certain traits
• that makes them perform better at the DV (CONTEXT)
• was not the IV that affected DV
• lowers internal validity

Question 7

How is individual differences controlled in independent groups design?

Answer 7

• random allocation

WHY
- ensures all ppts have same chance of being in each condition
- unlikely that all ppts in one condition share a trait to make them perform better at DV

HOW
1. write names of ppts on equal sized papers
2. put paper in hat
3. randomly pick out ppts names place half in condition 1 and half in condition 2 (CONTEXT)

Question 8

One problem with repeated measures design?

Answer 8

• order effects
• ppts take part in all conditions
• may perform better/worse in 2nd condition
• due to practice/fatigueness
• or 1st condition may have lasting effects on the 2nd condition (CONTEXT)

Question 9

How is order effects balanced in repeated measures designs?

Answer 9

Counterbalancing

WHY
- to control/reduce order effects

HOW
1. half ppts complete condition A then condition B (CONTEXT)
2. other half completes B first then A
3. order effects balanced/distributed across both conditions