Control, Demand Characteristics & Investigator Effects

Question 1

What are extraneous variables?

Answer 1

Any variable other than IV that might affect DV & thus affect results

Question 2

What are situational variables?

Answer 2

Variables connected with research situation, e.g. temperature, time for day, lighting, etc.
Controlled through standardisation, ensuring only thing which differs between 2 groups is IV, e.g. making sure temperate, time of day & lighting same fro both groups

Question 3

What are participant variables?

Answer 3

Variables connected with research participants, e.g. age, intelligence, gender, etc.
Controlled through experimental design, such as matched pairs design, or by randomly allocating participants to conditions, which helps to reduce bias

Question 4

Why do some psychologists use random allocation in their experiments?

Answer 4

Greatly decreases possibility participant variables in form of individual differences, like maths ability, will adversely affect results

Question 5

Why do some psychologists counterbalance in their experiments?

Answer 5

To combat problem of order effects with repeated measures design

Question 6

What is meant by randomisation?

Answer 6

When trials presented in random order to avoid any bias that order of trials might present

Question 7

What is meant by standardisation?

Answer 7

All situational variables of procedure used kept identical - methods sensitive to any change in performance - under these circumstances changes in data can be attributed to IV
Also far more likely results will be replicated on subsequent occasions when research standardised

Question 8

What is meant by demand characteristics?

Answer 8

Can act as confounding variable which can affect result of research

When participants try to make sense of research & change behaviour accordingly so support what they believe are aims of investigation - not displaying natural behaviour

Question 9

How do we control demand characteristics?

Answer 9

Not allowing participants to guess aim of research or identity IV, done by single-blind experimental technique
Single-blind technique - only researcher knows true aim of experiment & measure of deception used so aim not easily guessable - parties unable to support/undermine research on purpose

Question 10

What are investigator effects?

Answer 10

Researcher consciously or unconsciously acts in way to support their prediction
Problem when observing events that can be interpreted in different ways

Question 11

How do we control investigator effects?

Answer 11

Don’t allow participant or researcher to know aim or research &/or identity of IV
Achieved using double-blind experimental technique:
Only person who designed experiment knows true aim & measure of deception used so participant & researcher unaware