Unit 1 AS Level Psychology

Experiments

an investigation that allows researchers to determine CAUSE AND EFFECT relationships

Independent variable

factor being manipulated; makes change in DV

Dependent variable

factor being measured

Operationalized

a clear definition of a variable so that it can be accurately manipulated, measured, or quantified and the study can be replicated

Uncontrolled variable

Variables that act randomly affecting the DV

Confounding variable

An uncontrolled variable that effects ONE LEVEL of the experiment

Experimental variable

One or more situations in an experiment; levels of the IV

Control variable

Condition in which the IV is absent; what is natural

Independent measures

A different group of participants are used for each level of the IV; 1 group per IV

Repeated measures

Each participant performs every level of IV; each group in IV

Matched pairs

Participants are arranged into similar pairs; one of ½ pair in IV

Demand characteristics

features of the experiment which gives away the aims; causes participants to change their behavior

Random allocation

participants are randomly put in different levels of the IV. They have an equal chance of being selected for both, so this makes the sample diverse

Randomization

each participant is allocated to perform in different levels of the IV. equal chance of participating in levels in any order

Counterbalancing

each possible order of the IV is performed by each different sub group

• also known as “ABBA design”

Order effects

consequences of participating in the study more than once

Practice effect

situation where participant’s performance improves because they were experiencing the task more than once 

Fatigue effect

a situation where participants performance declines because they are physically tired or bored of the same task