Complete LUKO UNIT 2

Hindsight Bias

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

Theory

An explanation using an integrated set of principles that organizes and predicts observations.

Hypothesis

A testable prediction, often implied by a theory.

Operational Definition

Carefully worded statement of the exact procedures used in a research study.

Replication

Repeating the essence of a research study with different participants to see if findings extend to other circumstances.

Case Study

Descriptive technique in which one individual or group is studied in depth to reveal universal principles.

Naturalistic Observation

Observing and recording behavior in naturally occurring situations without manipulation.

Survey

Technique for ascertaining self-reported attitudes or behaviors of people, usually by questioning a representative sample.

Sampling Bias

Flawed sampling process that produces an unrepresentative sample.

Population

All those in a group being studied, from which samples may be drawn.

Random Sample

Sample that fairly represents a population because each member has an equal chance of inclusion.

Correlation

Measure of the extent to which two variables change together and how well either variable predicts the other.

Correlation Coefficient

Statistical index of the relationship between two variables, ranging from -1 to +1.

Scatter Plot

Graphed cluster of dots representing the values of two variables, indicating direction and strength of correlation.

Illusory Correlation

Perception of a relationship where none exists.

Experimental Group

Group exposed to treatment in an experiment.

Control Group

Group not exposed to treatment, serving as a comparison for evaluating the effect of the treatment.

Experiment

Research method where an investigator manipulates one or more factors to observe effects on behavior or mental processes.

Random Assignment

Assigning participants to groups by chance to minimize preexisting differences.

Double Blind Procedure

Experimental procedure where both participants and staff are unaware of treatment assignments.

Placebo

Experimental results caused by expectations alone; effects from an inert substance assumed to be active.

Independent Variable

Experimental factor that is manipulated; variable whose effect is being studied.

Confounding Variable

Factor other than the independent variable that might produce an effect in an experiment.

Dependent Variable

Outcome factor that may change in response to manipulations of the independent variable.

Mean

Arithmetic average of a distribution, calculated by adding scores and dividing by the number of scores.

Median

Middle score in a distribution, with half the scores above and half below it.

Range

Difference between the highest and lowest scores in a distribution.

Standard Deviation

Computed measure of how much scores vary around the mean score.

Normal Curve

Symmetrical, bell-shaped curve describing the distribution of many types of data, with most scores near the mean.

Statistical Significance

Statistical statement of how likely it is that an obtained result occurred by chance.

Informed Consent

Ethical principle requiring that research participants are informed enough to choose whether to participate.

Debriefing

Post-experimental explanation of a study, including its purpose and any deceptions, to participants.

Hawthorne Effect

Change in behavior of people who know they are being watched in an experiment.

Longitudinal Study

Study where one group of subjects is followed and observed over an extended period.

Cross-Sectional Study

Examines a representative cross-section of the population and tests/surveys subjects at one specific time.