Research Methodology and Experimental Design

Peer reviewers

Peer reviewers

Individuals who evaluate the quality of scientific research before it is published

Theory

A well-developed set of ideas that propose an explanation for observed phenomena

Hypothesis

A testable prediction about the relationship between two or more variables

Falsifiable

Capable of being proven wrong through empirical observation

Operational Definition

Defining a variable in terms of the specific procedures used to measure or manipulate it

Replication

Repeating a research study to confirm the results

Case Study

In-depth analysis of an individual, group, or event

Meta-Analysis

Statistical technique for combining the findings from multiple studies on a topic

Naturalistic Observation

Observing and recording behavior in naturally occurring situations without manipulation or control

Survey

Research method that involves asking people to report their behavior or opinions

Social desirability bias

Tendency for participants to respond in a way they believe is socially acceptable

Self-report bias

Errors in self-reported data due to factors like memory recall or social desirability

Experimenter Bias

Researcher's expectations influencing the outcome of a study

Population

Complete set of individuals or events that meet specific criteria

Sample

Subset of a population selected for a study

Sampling Bias

Error in research results due to a non-random sample selection

Random Sample

Subset of a population chosen through a random selection process

Convenience Sampling

Choosing a sample based on ease of access or availability

Representative Sample

Sample that accurately reflects the characteristics of the population

Experimental Methodology

Research approach involving manipulation of variables to test cause-and-effect relationships

Non-Experimental Methodology

Research approach that does not involve manipulation of variables

Correlation

Statistical measure of the relationship between two variables

Correlation Coefficient

Numeric value indicating the strength and direction of a correlation

Scatterplot

Graphical representation of the relationship between two variables

Illusory Correlation

Perception of a relationship between variables when none exists

Directionality Problem

Difficulty determining the direction of cause and effect in a relationship

Third Variable/Confounding Variable Problem

External factor that affects the relationship between two variables

Regression Toward the Mean

Tendency for extreme scores or behavior to return to average

Experiment

Research method used to establish cause-and-effect relationships

Experimental Group

Group in an experiment that receives the treatment being studied

Control Group

Group in an experiment that does not receive the treatment

Independent Variable(s)

Variable(s) manipulated by the researcher in an experiment

Dependent Variable(s)

Variable(s) measured to assess the effect of the independent variable

Random Assignment

Assigning participants to experimental and control groups by chance

Single-Blind Procedure

Participants are unaware of whether they are in the experimental or control group

Double-Blind Procedure

Both participants and researchers are unaware of group assignments

Placebo

Inert substance or treatment used as a control in experiments

Placebo Effect

Improvement in symptoms or condition due to a placebo

Experimenter Bias

a phenomenon that occurs when a researcher's expectations or preferences about the outcome of a study influence the results obtained

Validity

Extent to which a test or study measures what it is intended to measure