Chapter 3 Student Resources

Flashcards

Key Terms

Hypotheses

predictions concerning the effects of some factor(s) on behaviour based on a theory.

Experimental method

a method involving a generally high level of control over the experimental situation (especially the independent variable).

Experimental hypothesis

prediction as to what will happen in a given experiment; it typically involves predicting the effects of a given independent variable on a dependent variable and is often theory-based.

Independent variable

some aspect of the experimental situation manipulated by the experimenter to test a given experimental hypothesis.

Dependent variable

some aspect of the participants’ behaviour that is measured to test a given experimental hypothesis.

Null hypothesis

prediction that the independent variable (manipulated by the experimenter) will have no effect on the dependent variable (some measure of behaviour).

Confounding variables

variables not of interest to the experimenter erroneously manipulated along with the independent variable.

Sample

the participants actually used in a study drawn from some larger population.

Population

a large collection of individuals (e.g., female musicians) from whom the sample used in a study is drawn.

Representative sample

a sample of participants that is chosen to be typical or representative of the population from which it is drawn.

Random sampling

selecting the individuals for a sample from a population using some random process.

Quota sampling

selecting a sample from a population in such a way that those selected are similar to it in certain respects (e.g., proportion of females).

Opportunity sampling

selecting a sample of participants simply because they happen to be available.

Independent design

an experimental design in which each group consists of different participants.

Matched participants design

an experimental design in which the participants in each of two groups are matched in terms of some relevant factor or factors (e.g., intelligence; sex

Repeated measures design

an experimental design in which each participant appears in both groups

Random assignment

  allocating participants to groups at random (e.g., by tossing a coin).

Counterbalancing

this is used with the repeated measures design; each condition is equally likely to be used first or second with the participants.

Experimenter effect

influences of the experimenter’s behaviour on that of the participants in an experiment because of the expectations of the experimenter.

Ecological validity

the applicability or relevance of experimental findings to everyday settings.

Demand characteristics

cues used by participants to work out what the experiment is about.

Implacable experimenter

the typical laboratory situation in which the experimenter’s behaviour is uninfluenced by the participant’s behaviour.

Replication

repeating the findings of a study using the same design and procedures.

Inter-observer reliability

the extent of agreement between two observers rating the behaviour of participants.

Cross-sectional method

different groups (e.g., varying in age) are all studied at the same time.

Longitudinal method

one group of participants is tested repeatedly over a relatively long period of time.

Correlation

an association (positive or negative) between two dependent variables or responses produced by the participants.

Case study

the intensive study of one or a few individuals.