Methods of Psychological Research Overview

Systematic Data Collection

Scientific data collection must be systematic and minimize bias, involving defining the population of interest, selecting a representative sample, and choosing appropriate data collection methods.

Research Designs and Validity

Psychologists utilize various research designs like observational studies and experiments, each with strengths and weaknesses impacting internal and external validity.

Internal Validity

The degree to which the study design allows for confident conclusions about cause and effect.

Descriptive Statistics

Statistical procedures used to summarize and describe the main features of a dataset, such as measures of central tendency (mean, median) and variability (standard deviation).

Inferential Statistics

Statistical procedures used to draw conclusions about a population based on data collected from a sample.

Correlation

A statistical measure that indicates the extent to which two variables are related.

Case Study

An in-depth investigation of a single individual, group, or event, often used to explore rare phenomena or generate hypotheses for further testing.

External Validity

The degree to which findings can be generalized to other populations and settings.

Reliability

The consistency of a measurement.

Correlation Coefficient (r)

A numerical value between -1.00 and +1.00 representing the strength and direction of a correlation.

Confidentiality

Protecting the privacy of research participants by ensuring that their identities and data are not disclosed to unauthorized individuals.

Control Group

In an experiment, the group of participants who do not receive the experimental treatment and serve as a baseline for comparison.

Debriefing

A process at the end of a study where researchers explain the true purpose of the research to participants, address any deception used, and answer any questions.

Demand Characteristics

Cues within a research setting that may lead participants to unconsciously alter their behavior to meet perceived expectations.

Dependent Variable

The variable measured in an experiment, hypothesized to be influenced by changes in the independent variable.

Double-Blind Design

An experimental procedure where neither the participants nor the researchers interacting with them know who is assigned to the experimental or control groups, minimizing bias.

Effect Size

A measure of the magnitude of an experimental effect, indicating the practical significance of a research finding.

Empirical Claims

Statements about the world that can be verified or disproven through observation or experimentation.

Experiment

A controlled research method where researchers manipulate an independent variable to determine its effect on a dependent variable, allowing for cause-and-effect conclusions.

Experimental Group

The group of participants in an experiment who receive the experimental treatment or manipulation.

Frequency Distribution

A summary of data that shows the number (or frequency) of observations within each category or interval.

Informed Consent

The ethical principle requiring researchers to obtain voluntary agreement to participate in research from participants after informing them about the study's purpose, procedures, risks, and benefits.

Inter-rater Reliability

Consistency among different observers coding behavior.

Mean

Average calculated by summing values, dividing by count.

Median

Midpoint value in a data distribution.

Meta-Analysis

Combines data from multiple studies for analysis.

Observational Study

Research method observing behavior without manipulation.

Placebo Effect

Change due to belief in treatment's effectiveness.

Population

Entire group of interest for research study.

Quasi-Experiment

Research design lacking random assignment to groups.

Random Assignment

Participants assigned randomly to experimental groups.

Random Sampling

Each population member has equal selection chance.

Replication

Repeating a study to verify original findings.

Sample

Subset of individuals from a larger population.

Standard Deviation (SD)

Measure of variation or dispersion in data.

Statistical Significance

Results unlikely to occur by chance alone.

Third-Variable Problem

Unmeasured variable affecting observed relationships.

Validity

Accuracy of a measurement reflecting intended concept.

Within-Subject Comparisons

Performance comparison of same participants across conditions.

Protection from Harm

Minimizing risks to participants in research.

Debriefing Session

Post-study explanation of research purpose to participants.

Replication Crisis

Difficulty in replicating psychological research findings.

Belmont Report

Ethical principles guiding research: respect, beneficence, justice.

Hypothesis

Testable prediction about the relationship between variables.

Variables

Factors that can change or vary in a study.

Experimental Design

Research method manipulating variables to establish causality.

Ethical Considerations

Guidelines ensuring participant welfare in research.