Psychology

Experiment

Research method that manipulates variables to understand behaviors and mental processes

Experimental

Something based on, used in, or derived from a scientific test or trial

Non-experimental

Not relating to tests, especially scientific ones

Independent variable

the factor that is manipulated in an experiment; the variable whose effect is being studied.

Random assignment

the process of assigning participants to experimental and control groups by chance, minimizing preexisting differences between the different groups.

Case study

a non-experimental technique in which one individual or group is studied in depth in the hope of revealing individual principles

Correlation

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

Meta-analysis

Combining data from multiple experiments over same topic to understand general trends/outcomes

Naturalistic observation

a descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.

Research design

Framework used for the planning, implementation and analysis of a study.

Hypothesis

a testable prediction often implied by a theory

Falsifiable

the possibility that an idea, hypothesis, or theory can be disproven by observation or experiment

Operational definitions

the exact procedures used to define a variable in a research study

Dependent variable

in an experiment, the outcome that is measured; the variable that may change when the independent variable is manipulated.

Confounding variable

a factor other than the factor being studied in an experiment that might influence a study’s results.

Sample

Strategies used to select a subset of individuals (a sample) from a larger population, to study and draw inferences about the entire population.

Population

all those in a group being studied from which random samples may be drawn

Representative sample

a small group of participants that accurately mirrors the key traits, demographics, and characteristics of a larger target population

Random sample

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

Convenience sampling

a non-probability research method where researchers select participants because they are easy to reach, close by, and willing to take part.

Generalizability

A broad statement, idea, or conclusion applied to a large group or category based on only a few specific examples or observations

Experimental group

The group exposed to the treatment within an experiment — that is, to one version of the independent variable.

Control group

in an experiment, the group not exposed to the treatment

Placebo

experimental results caused by expectations alone

Single-blind

an experimental procedure in which the research participants are ignorant (blind) about whether they have received the treatment or a placebo.

Double-blind

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo.

Experimenter bias

bias caused when researchers may unintentionally influence results to confirm their own beliefs.

Social desirability bias

Response bias where individuals tend to answer questions or behave in ways they believe will be viewed favorably by others.

Qualitative research

Research method that relies on in-depth, narrative data that are not translated into numbers

Quantitative research

Research to gain numerical/concrete measurements to understand relationships

Peer review

Other experts and scientists evaluate a study’s theory, originality, and accuracy

Replication

Repeating a study/experiment to test if outcomes are reoccurring

Informed consent

Ethical property of an experiment, ensuring participants understand the risks/aspects of an experiment before consent is given

Informed assent

Therapist must inform their client of anything that would affect their decision to enter into or continue treatment

Confidential

Not being shared with anyone else, stays in the session

Confederates

An actor or aide working with the researchers who pretends to be a regular participant

Debrief

explaining the research afterwards, including any temporary deception

Effect size

quantitative measure of the magnitude of the expiremental effect

Central tendency

The center or typical value in a set of scores

Variation

How much scores or behaviors differ from each other and from the average

Percentile rank

Percentage of scores equal to or less than a specific score

Mean

Average of all numbers

Median

Put numbers from greatest to least and find the middle

Mode

Number that repeats the most

Range

Biggest value minus the lowest value

Normal curve

Symmetrical Bell curve to understand data disribution

Skew

set of data is aasymmetrical/ stretched out to one side rather than forming a balanced, symmetrical bell curve

Bimodal distribution

a set of data or scores that has two distinct peaks instead of one.

Regression towards the mean

the tendency for extreme or unusual scores or events to fall back (regress) toward the average

Scatterplot

a graphed cluster of dots, each of which represents the values of two variables

Correlation coefficient

a statistical index of the relationship between two variables (from -1.00 to +1.00)

Effect size

Quantitative measure of the magnitude of the expiremental effect

Statistical significance

the degree to which a research outcome cannot reasonably be attributed to the operation of chance or random factors.