Unit 0: research methods

Hindsight Bias

The tendency to believe, after learning an outcome, that one would have foreseen it.

Confirmation Bias

A tendency to search for information that supports preconceptions and to ignore contradictory information.

Overconfidence

The tendency to be more confident than correct in one's beliefs or judgment.

Non-experimental research methods (descriptive research methods)

Various approaches to observation, measurement, manipulation, and control of variables in empirical studies.

Naturalistic Observation

Observing a human or animal in a natural setting.

Case Study

Studying an individual or a group in depth over a long period of time.

Survey

Used to obtain as much information about a topic in the most efficient way.

Self-report Bias

When people report their behavior inaccurately.

Sampling Bias

A flawed sampling process that produces an unrepresentative sample.

Random Sample

Fairly represents a population because each member has an equal chance of inclusion.

Sample

A collection of subjects selected for observation.

Representative Sample

The larger collection of animals or people (sample drawn here).

Convenience Sampling

No pattern in acquiring people, do what is most convenient to them.

Correlation

When variables relate to each other.

Positive Correlation

Indicates two variables co-vary in the same direction.

Negative Correlation

Indicates that two variables co-vary in opposite directions.

No (zero) Correlation

No relationship.

Correlation Coefficient

A numerical index of the degree of the relationship between two variables.

Scatterplot

A graph that is used to plot the data points for two variables.

Illusory Correlation

Perceives a relationship where none exists, or perceives a relationship as stronger than it is in actuality.

Experiment

A research method that determines cause and effect relationships.

Hypothesis

Testable prediction, often implied by a theory.

Operational Definition

Carefully worded statement of the variables being used.

Independent Variable

The factor that is manipulated; effect that is being studied → 'cause'.

Dependent Variable

The outcome that is measured; the variable that may change → 'effect'.

Confounding Variable

Other variables that might influence a study's results.

Experimental Group

Group exposed to the treatment; independent variable.

Control Group

Group not exposed to the treatment; contrasts with experimental group.

Placebo effect

When a person is given a fake treatment and seems to endure 'changes'.

Random Assignment

Assigning participants to experimental and control groups by chance.

Observer Bias

Occurs when the observers (or researcher team) know the goals of the study or the hypotheses and allow this knowledge to influence their observations during the study.

Single-blind Procedure

An experimental procedure in which the research participants are ignorant (blind) about whether they have received the treatment or a placebo.

Double-blind procedure

An experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether research participants have received the treatment or a placebo.