Research Methodology

Anonymity

An ethical guideline that ensures complete privacy by preventing any link between responses and specific individuals.

Case study

A non-experimental method involving a detailed investigation of an individual or a small group using various tools such as psychological tests, interviews, and subjective impressions.

Confederate

A member of the research team who pretends to be a participant to create specific situations or interactions necessary for the study.

Confirmation bias

A bias involving the tendency to search for information that supports one's preconceptions and beliefs and ignore/minimize contradictory evidence.

Confounding variable

Any factor other than the independent variable in an experiment that could impact the dependent variable, potentially leading to distorted results.

Convenience sampling

A type of sampling bias involving selecting participants who are readily available and easily accessible to the researcher.

Correlation coefficient

A descriptive statistic that is represented by the letter r, ranging from -1.0 to +1.0, indicating the strength and direction of the relationship between two variables.

Correlational study

A non-experimental research design intended to determine the strength and direction of the relationship between two or more variables.

Debriefing

An ethical guideline that involves the process of informing participants about the true nature of the study after its conclusion, including any deception used.

Dependent variable

The factor that researchers measure in an experiment to see if it is affected by the independent variable. It should be operationally defined.

Double-blind

A study design in which neither the researcher nor the participants know who is in the control or experimental group until after the data has been collected and analyzed.

Effect size

An inferential statistic that is a measure used to quantify the difference between two groups in an experimental study, indicating the magnitude of the effect of the independent variable.

Empiricism

Conclusions based on evidence, facts, and research, fundamental to the scientific method in psychology.

Experimental group

The group in an experiment that receives the independent variable or factor being manipulated.

Experimenter bias

The tendency for researchers to unknowingly influence the results of an experiment, often through subtle and unintended cues.

False-consensus effect

A bias in which individuals overestimate how many others agree with their beliefs, behaviors, or attitudes

Generalizability

The degree to which the results of a study (sample) can be applied to the larger population.

Hypothesis

A testable and falsifiable prediction about the relationship between variables guiding researchers in studying behavior and mental processes.

Independent variable

The factor that is manipulated by researchers in an experiment to observe its effect on the dependent variable. It is given only to participants in the experimental group(s).

Informed assent

An ethical requirement that involves obtaining agreement from individuals who cannot legally give full informed consent to participate in research, such as children or individuals with cognitive impairments.

Informed consent

An ethical requirement that invovles a written document given to research participants before a study that explains the procedures and risks and lets them know they may quit at any time.

Institutional Review Board (IRB)

An ethical requirement that involves a committee created to examine potential research projects before they are conducted to ensure ethical procedures are followed and participants are protected from harm.

Likert scale

A quantitative measurement instrument frequently employed in surveys and assessments, where participants express their level of agreement or disagreement with statements by selecting from a range of response options.

Meta-analysis

A non-experimental method that involves statistically combining the results of many studies on the same topic to draw a conclusion based on a larger sample.

Naturalistic observation

A non-experimental research method involving carefully and systematically watching human or animal behavior as it occurs in the natural environment.

Null hypothesis

A testable and falsifiable prediction that the independent variable does not cause the dependent variable or that there is no difference between the control and experimental groups.

Operational definition

A clear and measurable description of the variable(s) in a study, which allows for replication.

Peer review

The process of submitting research for evaluation by experts in the field to ensure the study's validity, ethics, and quality before publication.

Placebo

A fake treatment that is given to the control group in an experiment.

Placebo effect

Occurs when a physical or psychological treatment that has no active ingredient produces an effect because the person receiving it believes that it will.

Population

Includes all group members that could be selected for the research sample and to whom the results apply.

Qualitative measurement instruments

Designed to collect descriptive, non-numerical data to find meaning and context, often exploring complex phenomena in depth. Example: structured interviewss.

Quantitative measurement instruments

Designed to collect numerical data for statistical analysis. Example: Likert scales

Random assignment

The process of placing participants into either a control or experimental group by chance, ensuring that each participant has an equal chance of being placed in any group.

Random sample

A subset of the population consisting of participants chosen without any predetermined pattern, ensuring every member of the population had an equal chance of being selected.

Random sampling

Methods used to generate a random sample from a population, increasing the likelihood that the results can be generalized to the larger population.

Replication

The process of duplicating a research study to strengthen confidence in the findings by obtaining the same or similar results. Requires operational definition.

Representative sample

A sample that is similar to the population as a whole with regard to variables that might impact the results.

Sampling bias

A bias involving any method of collecting a subset of the population that results in a group (sample) that is either not random or not representative of the population.

Self-report bias

A bias in which participants inaccurately report behaviors, feelings, or attitudes is often due to memory errors or, in some cases, social desirability bias.

Single-blind procedure

A study design in which participants are unaware of whether they are receiving the experimental treatment or a control condition.

Social desirablity bias

A bias in which participants answer dishonestly to match the experimenter's expectations or create a favorable impression.

Standard deviation

a computed measure of how much scores vary around the mean score

Survey technique

Involves collecting and analyzing data or opinions using self-report questionnaires to discover the beliefs, opinions, and attitudes of a sample.

Third-variable problem

Occurs when two variables are found to be correlated, but both are actually caused by another, often unknown, factor.

Validity

The extent to which a test or instrument measures what it is supposed to measure - accuracy.

Variable

Any factor that can vary or change in an experiment, affecting the outcome of the study.

Directionality problem

a problem encountered in correlational studies; the researchers find a relationship between two variables, but they cannot determine which variable may have caused changes in the other variable

Reliability

The extent to which a test yields consistent results, as assessed by the consistency of scores on two halves of the test, on alternate forms of the test, or on retesting

Regression toward the mean

The tendency for extreme or unusual scores to fall back toward their average.

Protection from harm

The ethical requirement during research that participants should not experience negative physical or psychological effects, such as physical injury, lowered self-esteem, or embarrassment

Deception

The act of misleading participants about the true purpose of a study or the events that will actually transpire which must be approved in advance by an IRB and debriefed.

Survey

A technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group

Wording effects

The effect that subtle changes in the words or order of words can have on a study participant's responses often in a survey or structured interview.

Mean

The arithmetic average of a distribution that is obtained by adding the scores and then dividing by the number of scores. A measure of central tendency.

Median

The middle score in a distribution; half the scores are above it and half are below it. A measure of central tendency.

Mode

The most frequently occurring score(s) in a distribution. A measure of central tendency.

Measure of central tendency

A descriptive statistic that tells which result or score best represents an entire set of scores. Includes mean, median, and mode.

Percentile rank

The percentage of scores below a specific score in a distribution of scores.

Normal curve

The symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes. Most scores fall near the average, and fewer and fewer scores lie near the extremes. The mean, median, and mode are all the same and located at the center of the distribution.

Frequency distribution

An arrangement of data that indicates how often a particular score or observation occurs

Range

A measure of variance that is the difference between the highest and lowest scores in a distribution.

Statistical significance

The condition that exists when the probability that the observed findings are due to chance is very low.

Inferential statistic

A group of statistics that uses sample data to make general estimates about the larger population

Descriptive statistics

A group of statistics that summarize the data collected in a study

Positive correlation

A relationship where as one variable increases, the other also increases, or as one decreases so does the other. Both variables move in the same direction.

Negative correlation

A relationship between two variables in which one variable increases as the other variable decreases

Positive (right) skew

A distribution that has an abundance of low scores and relatively few high scores.

Negative (left) skew)

A distribution that has an abundance of high scores and relatively few low scores.

bimodal distribution

A frequency distribution having two different values that are the most common.

Hindsight bias

A bias involving the tendency to believe, after learning an outcome, that one could have foreseen it. "I know it all along phenomenon."

Overconfidence effect

A bias involving the tendency to overestimate how correct one's predictions, judgments, and beliefs are.