Unit 3 – Psychology
Chapter 1 – Research Methodologies
Independent: the variable that is systematically manipulated.
Dependent: the variable which measures the effects of the IV.
Extraneous: a variable that may or may not have an effect on the DV.
Confounding: a variable that had an undesired effect on the DV
Matched Participants Design: pairing based on similar characteristics, minimising extraneous
Repeated Measures Design: one group that is exposed to both the experimental group and
the control group. Eliminating extraneous variables
Independent Groups Design: randomly allocating the members of the sample to either the
experimental or control group.
Types of Sampling:
Convenience: selection due to availability.
Random: planned and systematic system of selecting participants for study.
Stratified: breaking the population into distinct sub-groups, selecting sample from each group
to represent the population
Random-Stratified: breaking the population into subgroups and selecting randomly from
Counterbalancing: control the order effects like practice & carry-over effects. Attempts to
control the unwanted effects on performance of any one order by systematically changing
the order of the treatments in a ‘balanced way’
Single-Blind: eliminates the placebo effect. Participants are unaware of whether they are
experimental or control groups.
Double-Blind: the experimenter is unaware of which participant is exposed to either the
experimental or control group. Controlling experimenter effects.
Placebo: is a fake treatment used in the control group to compare to the experimental group.
Standardised Instructions and Procedures:
Standardised: pre-rehearsed sets of instructions that are expressed to the participants with a
neutral voice by the researcher. They also have answers that are anticipated for questions
that may arise.
Non-Standardised: each participant will...