Approaches and Research Methods 2026

Psychology

the scientific study of behavior and mental processes

Psychiatrist

A medical doctor who has specialized in the diagnosis and treatment of psychological disorders

Behavioral perspective

The approach that suggests that observable, measurable behavior should be the focus of study.

Biological psychology

a branch of psychology concerned with the links between biology and behavior

Cognitive psychology

the scientific study of mental processes, including perception, thought, memory, and reasoning

Evolutionary perspective

the study of the roots of behavior and mental processes using the principles of natural selection

Humanistic perspective

an approach to understanding human nature that emphasizes the positive potential of human beings

Psychoanalytic perspective

the perspective that stresses the influences of unconscious forces on human behavior

Social-cultural perspective

school of thought that focuses on how thinking or behavior changes in different situations or as a result of cultural influences

Gestalt Psychology

a psychological approach that emphasizes that we often perceive the whole rather than the sum of the parts

hindsight bias

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

overconfidence

the tendency to be more confident than correct—to overestimate the accuracy of our beliefs and judgments.

Theory

A hypothesis that has been tested with a significant amount of data

Falsifiability

a feature of a scientific theory, in which it is possible to collect data that will prove the theory wrong

operational definition

a statement of the procedures used to define research variables

Replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

case study

a descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles

naturalistic observation

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

survey

the collection of data by having people answer a series of questions

social desirability bias

the tendency for people to say what they believe is appropriate or acceptable

self-report bias

when people report their behavior inaccurately

Population

all those in a group being studied, from which a random sample is taken

random sample/selection

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

sampling bias

a flawed sampling process that produces an unrepresentative sample

convenience sampling

using a sample of people who are readily available to participate

representative sample

a sample that accurately reflects the characteristics of the population as a whole

Unrepresentative Sample

drawing a conclusion from a sample that does not represent the general population

Correlation

A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.

correlation coefficient

a statistical measure of the extent to which two factors vary together, and thus of how well either factor predicts the other

Variable

A factor that can change in an experiment

Scatter Plot Graph

tool that displays data from two related sets as ordered pairs; shows a set of similar things

positive correlation

A correlation 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

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

random assignment

assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups

experimental group

the group in an experiment that receives the variable being tested

control group

In an experiment, the group that is not exposed to the treatment; serves as a comparison for evaluating the effect of the treatment.

double-blind procedure

A research strategy in which neither subjects nor experimenters know which subjects are in the experimental or control groups.

Placebo

something which has a positive mental effect, but no physical effect

placebo effect

the phenomenon in which the expectations of the participants in a study can influence their behavior

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

dependent variable

The measurable effect, outcome, or response in which the research is interested.

confounding variable

in an experiment, a factor other than the independent variable that might produce an effect

Validity

the extent to which a test measures or predicts what it is supposed to

longitudinal study

research in which the same people are restudied and retested over a long period

cross-sectional study

a study in which people of different ages are compared with one another

Qualitative Research

seeks in-depth, open-ended responses, not yes or no answers; not numerical

Quantitative Research

research that collects and reports data primarily in numerical form

Informed Consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

Debriefing

the post-experimental explanation of a study, including its purpose and any deceptions, to its participants

IRB

Institutional Review Board, review research in advance to ensure ethical considerations are met

Histogram

a bar graph depicting a frequency distribution

mean

average

Median

the middle score in a distribution; half the scores are above it and half are below it

Mode

the most frequently occurring score(s) in a distribution

range

the difference between the highest and lowest scores in a distribution

standard deviation

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

normal curve

the bell-shaped curve that describes the distribution. Most scores fall near the average, and fewer scores lie near the extremes

Statistical Significance

a statistical statement of how likely it is that an obtained result occurred by chance

p-value < 0.05

statistically significant

68%

1 standard deviation