Experimental methods Flashcards
Aims
A general expression of what the researcher intends to investigate
Operationalised hypotheses
A statement of what the researcher believes to be true
It should be operationalised (i.e. clearly defined and measurable)
Directional hypothesis
A directional hypothesis states whether changes are greater or lesser, positive or negative, etc. (used when theory/research suggests the direction)
Non-directional hypothesis
A non-directional hypothesis doesn’t state the direction, just that there is a difference, correlation, association (used when there is no theory/previous research or it is contradictory)
IV & DV
Extraneous variables
EVs
Confounding variables
CVs 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
Demand characteristics
Refers to any cue from the researcher or research situation that may reveal the aim of the study, and change the participant’s behaviour
Investigator effects
Any effect of the investigator’s behaviour on the outcome of the research (the DV) and also on design decisions
Randomisation
The use of change when designing investigations to control for the effects of bias e.g. allocating participants to conditions
Standardisation
Using small-scale trial run of an investigation to ‘road-test’ procedures, so that research design can be modified
Pilot studies
Small-scale trial run of an investigation to ‘road-test’ procedures, so that research design can be modified
Control groups/conditions
Control groups (independent groups design) or control conditions (repeated measures design) are used to set comparison
They act as a baseline and help establish causation
Single blind and double blind
Single blind - a participant doesn’t know the aims of the study so that demand characteristics are reduced
Double blind - both participants and researcher don’t know the aims of the study to reduce demand characteristics and investigator effects
