Experimental Method

Question 1

Aim

Answer 1

A general expression of what the researcher intends to investigate

Question 2

Hypothesis

Operationalised

Answer 2

A statement of what the researcher believes to be true. It should be operationalised

ie clearly defined and measurable

Question 3

Directional Hypothesis

Answer 3

States whether the changes are greater or lesser, positive or negative etc

Question 4

Non-directional Hypothesis

Answer 4

Doesn’t state the direction just that there is a difference, correlation, association

Question 5

Experimental Method

Answer 5

A researcher causes the independent variable (IV) to vary and records the effect of the IV on the dependent variable (DV)

Question 6

Extraneous Variables (EV’s)

Answer 6

Nuisance variables that do not vary systematically with the IV. A researcher may control some of these

Question 7

Confounding Variables (CV’s)

Answer 7

Variables that do change systematically with the IV so we cannot be sure if any observed change in the DV is due to the CV or the IV. CV’s must be controlled

Question 8

Demand Characteristics

Answer 8

Refers to any cue from the researcher or research situation that may reveal the aim of the study

Question 9

Investigator Effects

Answer 9

Any effect of the investigator’s behaviour on the outcome of the research (the DV)

Question 10

Randomisation

Answer 10

The use of chance when designing investigations to control for the effects of bias

Question 11

Standardisation

Answer 11

Using exactly the same formalised procedures for all participants in a research study

Question 12

Control Groups

Answer 12

Control groups are used for the purpose of setting a comparison.
They act as a baseline and help to establish causation

Question 13

Single Blind

Answer 13

A participant doesn’t know the aims of the study so that demand characteristics are reduced

Question 14

Double Blind

Answer 14

Both participant and researcher don’t know the aims of the study to reduce demand characteristics and investigator effects

Question 15

Independent Groups

Two Strengths

Two Limitations

Answer 15

One group do condition A and a second group do condition B.
Participants should be randomly allocated to experimental groups

+ No order effects
+ Will not guess aim

• Participant variables
• More participants

Question 16

Repeated Measures

Two Strengths

Two Limitations

Answer 16

Same participants take part in all conditions of an experiment
The order of conditions should be counterbalanced to avoid order effects

+ Participant variables
+ Fewer participants

• Order effects are a problem
• Participants may guess aims

Question 17

Counterbalancing

What happens?

Answer 17

An attempt to control order effects in a repeated measures design

In counterbalancing, half the participants take part in condition A then B, and the other half take part in condition B then A.

Question 18

Participant Variables

Answer 18

May act as confounding variables in an independent groups designs because people in each condition are different. This may be the cause of the change in the DV- rather than the manipulation of the IV

Question 19

Order Effects

Answer 19

Come about when participants are tested more than once- as in repeated measures designs. This might lead to better performance through practice, or worse performance due to boredom or fatigue

Question 20

Matched Pairs

Two Strengths

Two Limitations

Answer 20

Two groups of participants are used but they are also related to each other by being paired on participant variable(s) that matter for the experiment

+ Participant variables
+ No order effects

• Matching is not perfect
• More participants