Experimental method terminology

Question 1

Independent variable

Answer 1

manipulated by researcher or changes naturally so effect in dependent variable can be measured

Question 2

Dependent variable

Answer 2

Variable measured by researcher. Any effect on it should be caused by change in IV

Question 3

Extraneous variable

Answer 3

Any variable other than IV that may affect DV if not controlled. They’re nuisance variables that don’t vary systematically with IV

Question 4

Confounding variables

Answer 4

A kind of EV but varies systematically with IV. Therefore we can’t tell if any change in DV is due to IV or CV

Question 5

Aim

Answer 5

General expression of what researcher intends to investigate

Question 6

Operationalised hypotheses

Answer 6

Statement of what researcher believes to be true, should be clearly defined and measurable

Question 7

Directional hypothesis

Answer 7

States whether changes are < or >, + or -

Question 8

Non-directional hypothesis

Answer 8

doesn’t state direction, just that there’s difference, correlation, association. Used when there’s no theory/previous research or it’s contradictory

Question 9

Demand characteristics

Answer 9

Refers to any cue from researcher or research situation that may reveal aim of study, and change participants’ behaviour

Question 10

Investigator effects

Answer 10

Any effect of investigator’s behaviour on outcome of research (DV) and also on design decisions

Question 11

Randomisation

Answer 11

Use of chance when designing investigations to control for effects of bias

Question 12

Standardisation

Answer 12

Using exactly same formalised procedures for all parts otherwise differences become EV

Question 13

Pilot studies

Answer 13

Small-scale trial run of investigation to test procedures so that research can be modified

Question 14

Control groups/control conditions

Answer 14

used to set comparison . Act as baseline and help establish causation

Question 15

Control groups

Answer 15

Experiment with independent groups design, group of participants who receive no treatment. Their behaviour acts as baseline against which the effect of IV may be measured

Question 16

Control conditions

Answer 16

Condition in repeated measures design that provides baseline measure of behaviour

Question 17

Single blind

Answer 17

Participant doesn’t know aims of study so demand characteristics are reduced

Question 18

Double blind

Answer 18

Participant and researcher don’t know aims of study to reduce demand characteristics and investigator effects

Question 18

Random allocation

Answer 18

Attempt to control for PV in independent groups design which ensures each participant has same chance of being in 1 condition as any other

Question 18

Experimental groups

Answer 18

Group in independent groups design containing IV as distinct from control

Question 19

Counterbalance

Answer 19

Attempt to control effects of order in repeated measures design: half participants experience conditions in 1 order and other half in opposite order

Question 19

Validity

Answer 19

Whether observed effect is genuine

Question 20

Order effects

Answer 20

Participants tested more than once - may lead to better performance through practice, or worse performance due to boredom or fatigue

Question 21

Situational variables

Answer 21

characteristics of situation

Question 22

Participant variable

Answer 22

characteristics of participants