A method to assure the accuracy of translation by having the research materials translated twice (by different individuals)—first into the second language, and then from the second language back into the first.

A process in which researchers describe a study’s procedures and determine whether participants agree to take part.

The different settings in a research design, which contain different levels of the independent variable.

In an experimental design, the variable that is potentially influenced by the manipulation of the independent variable.

A measure of electrical resistance at the skin that uses the activity of sweat glands to provide a physiological measure of anxiety.

A detailed analysis of one particular person or group of people; the person or group is the “case.”

Any property that fluctuates, such as from person to person or from time to time.

A research method in which researchers learn about various characteristics of a given individual by obtaining reports from other people who know that person.

A statistic that describes the degree to which numbers vary, or deviate, from the mean.

A factor other than the independent variable that might create differences between experimental conditions.

A sample in which the qualities of the individuals included match those of the overall population.

In science, a systematic, data-based explanation for a phenomenon or set of phenomena.

A technique for recording and visually depicting electrical activity within the brain in which electrodes on the scalp record neural activity in underlying brain regions. The record of electrical activity through this method is called an electroencephalogram.

A sample in which each individual’s inclusion, or not, is determined by a chance process.

Research techniques in which researchers ask participants to provide information about themselves.

In psychology, an analysis of someone receiving psychological therapy; generally a written summary of a case.

A statistical technique for combining results from multiple studies in order to identify overall patterns in the studies as a whole.

A numerical value that represents the strength of a correlation between any two variables.

Any procedure in which numbers are assigned to objects or events.

Mathematical procedures for summarizing sets of numbers.

A field of study that provides scientific information about the relation between physiological reactions and psychological experiences.

A type of research in which researchers collaborate with community residents to determine a study’s goals and research procedures.

A research method in which researchers view the actions of research participants firsthand and record the behaviors they observe, often by counting specific behaviors.

In an experimental design, any variable that the experimenter manipulates in order to see its effect on another variable.

The select subgroup of people contacted by a researcher, who uses information from the sample to draw conclusions about the population as a whole.

Scientific methods in which participants’ responses are described in terms of numbers.

A correlation in which higher levels of one variable co-occur with lower levels of the other variable.

A set of questions or statements to which participants respond by choosing response options that best characterize their own thoughts.

An attribute of a measure; specifically, a measure possesses “reliability” if it produces results that are consistent from one measurement occasion to another.

Numerical data, that is, data in which scientific observations are recorded using numbers.

An experimental condition that does not receive the experimental treatment.

An attribute of a measure; specifically, a measure possesses “validity” if it measures what it is supposed to measure.

Any type of information obtained in a scientific study.

A research design whose aim is to determine the relation between two or more measured variables.

The overall, large group of people of interest to a researcher conducting a study.

A prediction about the result of a study.

A research design in which a variable is manipulated, with a goal of identifying the causes of events.

A graph that displays the relation between two variables. Data points representing the measurements of the two variables “scatter” about the visual display.

A process in which participants are allocated to conditions of an experiment on an entirely chance basis.

The average score in a distribution.

A group of professionals who assess the ethics of a proposed research study.

Any of a wide range of methods in which researchers observe, record, and summarize behavior using words rather than numbers.

A brain-scanning method that depicts activity in specific regions of the brain as people engage in psychological activities.

An experimental result is said to be statistically significant if observed outcomes vary from what would be expected by chance.

A correlation (statistical relation between two variables) in which higher levels of one variable co-occur with higher levels of the other variable.

The specification of a procedure that can be used to measure a variable.

Sources of scientific information that are not converted into numbers, but reported in words.

Plans for the execution of scientific research projects.

The researcher’s plan for manipulating one or more variables in an experiment.

A research design in which researchers obtain descriptive information about a large group of people by studying a select subgroup of them.

A type of research in which researchers observe people’s behavior from a distance without interacting with them.