EXP DESIGN AO1 & AO3

Question 1

Experimental Design

Answer 1

• Allocating participants to conditions
• Independent measures, repeated measures, matched pairs

Question 2

Repeated measures

Answer 2

Each pts takes part in both conditions

Question 3

Repeated measured ADVANTAGE

Answer 3

• Any difference between conditions likely to be due to IV not pts variables
  Controls individual differences
• ** (removes EV)** = compares participant’s scores from one condition with their score from condition 2 = increase internal validity
• Requires less pts

Question 4

How to deal with practice and order effects

Answer 4

• In any repeated measures design = consider controlling P&E effects
• Can’t get rid of P&E effects = only control + reduce them
  Using technique counterbalancing – specifically called ABBA
  Half of pts do condition A then B
  Other half do B then A
  Assign pts randomly to conditions
• Also, can use randomisation – presentational order of conditions is decided by use of random generators.
• Decide which half of the class gets which condition

Question 5

order and effects

Answer 5

• Order effects can occur in a repeated measures design and refers to how the positioning of tasks influences the outcome
• e.g. practice effect or boredom effect on second task

Question 6

Matched pairs

Answer 6

• Each person in one condition is matched with someone in the other condition on a range of important factors (dependent on study) e.g. age, gender, IQ
• control P&E effects of repeated measures + individual differences of independent measures

Question 7

Matched pairs ADVANTAGE

Answer 7

• Controls individual differences (pts matched on key factors = controls individual differences)
• Controls P&E effects (pts do only 1 condition = no P&E effects)

Question 8

Matched pairs DISADVANTAGE

Answer 8

• Practically difficult
• Hard to decide which factors are important (always be other potential factors that should have been matched)
  How do we measure the variable we match? E.g. IQ test?
• Hard to find a match – large sample size

Question 9

Independent measures

Answer 9

• Divided randomly into 2 groups + each does a different condition of IV

Question 10

Ind measures ADVANTAGE

Answer 10

Each pts sees only ½ of study = harder for them to work out aim of study = reduces demand characteristics

Avoids practice & order effects = pts only does 1 condition = cannot be affected by boredom/practice

Question 11

Ind measures DISADVANTAGE

Answer 11

Each pts only provides 1 piece of data = more pts needed

Consider impact of individual differences i.e. other factors influencing IV

Question 12

Randomisation

Answer 12

The use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions

Question 13

Standardisation

Answer 13

• All procedures are standardised in order all pts are subject to the same environments
  i.e. list of exactly what will be done in the study inc standardised instructions that are read to each pt

Question 14

Demand characteristics

Answer 14

• Features or cues in research which help participants work out what is expected of them
• participants may respond according to what they think is being investigated
  =invalid results

Question 15

Social desirability bias

Answer 15

• Pts behave to present themselves in the best light = not natural behaviour
• Researcher focuses on experimental realism = task is engaging + pts forget they are being observed = no social desirability bias

Question 16

Investigator effects

Answer 16

• Refers to any effect of the investigators behaviour (conscious/unconscious)on the research outcome
• i.e. interaction with pts or leading questions

Question 17

Pilot study

Answer 17

Allow researcher to identify any potential issues and to modify the design or procedure, saving time and money in the long term