Psychology Research Methods Vocabulary

Vocabulary flashcards covering core psychological research methods, statistics, and experimental terms.

anonymity

Means not collecting personal information from participants unless it is necessary

bimodal distribution

A frequency distribution having two different values that are heavily populated with cases

case study

An observation technique in which one person or a small group of individuals are studied in depth

confederate

In an experimental situation, an aide of the experimenter who poses as a participant but whose behavior is rehearsed prior to the experiment.

confidentiality

A principle of professional ethics requiring researchers to limit the disclosure of research participants and survey respondents' identity and any unique data collected during a study.

confirmation bias

A tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence

confounding variable

A factor other than the independent variable that produces an effect in an experiment. These are NOT wanted.

control group

Any group that receives any medical or psychological intervention or treatment that is believed to be "inert," thus making it valuable as a control condition against which to compare the intervention or treatment of interest.

control variable

That factors in an experiment other than the independent variable are held the same for all of the participants (ex: age, IQ range,)

convenience sampling

Any process for selecting a sample of individuals or cases that is neither random nor systematic but rather is governed by chance or ready availability. Data obtained from this method do not generalize to the larger population as there may be significant bias.

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 index of the relationship between two variables (from $-1$ to $+1$)

correlational study

A non-experimental research design that is intended to determine the strength ($-1.0$ through $+1.0$) and direction (positive or negative) of the relationship between two or more variables.

debriefing

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

deception

Any distortion of or withholding of fact with the purpose of misleading others.

demand characteristics

Participants form an interpretation of an experiment's purpose and unconsciously or consciously change their behaviors as a result.

dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable, what the researcher is measuring.

descriptive statistics

Statistical techniques used to summarize and describe the characteristics or properties of a dataset, such as measures of central tendency and variability.

directionality problem

In correlational research, the situation in which it is known that two variables are related although it is not known which is the cause and which is the effect.

double-blind procedure

An experimental procedure in which both the research participants and the research staff are not informed about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.

effect size

Measure the strength or practical importance of the relationship between the independent variable (IV) and the dependent variable (DV). They provide a clearer picture of how substantial the effect is rather than just whether it exists.

ethical guidelines

Rules of acceptable conduct that members of a given profession are expected to follow

experiment(al)

A research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable).

experimental group

In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable

experimental psychology

The study of behavior and thinking using the experimental method

experimenter bias

Occurs when a researcher's expectations or preferences about the outcome of a study influence the results obtained

falsifiable/falsifiability

The principle that for a hypothesis or theory to be considered scientific, it must be possible to conceive of evidence that would prove it false.

generalizability

Degree to which a study's findings based on a sample apply to the entire population (provided the sample is representative)

hindsight bias

The tendency to believe, after learning an outcome, that one would have foreseen it (also known as I-knew-it-all-along phenomenon)

hypothesis

A testable prediction, often implied by a theory

illusory correlation

The perception of a relationship where none exists

independent variable

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

inferential statistics

Statistical techniques used to make predictions about a population based on sample data, including hypothesis testing and estimation.

Informed assent

Obtaining agreement from individuals who cannot legally give full informed consent to participate in research, such as children or individuals with specific cognitive impairments.

informed consent

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

Institutional Review Board (IRB)

A committee at each college/university where every experiment is examined for ethics and methodology before it gets approval to be conducted

mean

The arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores

median

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

meta-analysis

A procedure for statistically combining the results of many different research studies

mode

The most frequently occurring score(s) in a distribution

naturalistic observation

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

negative correlation

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

negative skew

The degree to which a set of scores, measurements, or other numbers are asymmetrically distributed with a majority toward the high end of the distribution with a few extreme scores toward the low end.

non correlation

Two variables are not related to each other

non-experimental

Research in which the investigator cannot randomly assign units or participants to conditions, cannot generally control or manipulate the independent variable, and cannot limit the influence of extraneous variables. Includes correlation, meta-analysis, case study, and naturalistic observations.

normal curve (normal distribution)

A symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean ($68\%$ fall within one standard deviation of it) and fewer and fewer near the extremes

operational definition

A carefully worded statement of the exact procedures or measurements used in a research study.

P-value

The probability of results of the experiment being attributed to chance.

participant bias

A tendency for research participants to respond in a certain way because they know they are being observed, they believe they know if they are receiving treatment or a placebo, or they believe they know what the researcher wants

participant variables

Factors related to differences in subjects and include individual differences such as age, gender, education level, intelligence, ethnicity, personality, values, past experiences, and demand characteristics.

peer review

The evaluation of scientific, academic, or professional work by others in the same field to ensure its quality and validity before publication or presentation.

placebo

Treatment used to establish controls and prevent participant bias

placebo effect

Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent

population

All the cases in a group being studied, from which samples may be drawn. (Represented by uppercase $N$)

positive correlation

A relationship between two variables in which both rise and fall together.

positive skew

The degree to which a set of scores, measurements, or other numbers are asymmetrically distributed with a majority toward the low end of the distribution with a few extreme scores toward the high end.

protection from harm

Reasonable steps taken to avoid and minimize adverse effects for research participants where it is foreseeable and unavoidable.

qualitative research methods

Research that focuses on gathering and analyzing non-numerical data, such as observations, interviews, or textual analysis, to understand meanings, experiences, or perspectives.

quantitative research methods

Research that focuses on gathering and analyzing numerical data to understand relationships, patterns, or trends.

quasi experiment

An experiment in which investigators make use of control and experimental groups that already exist in the world at large.

range

The difference between the highest and lowest scores in a distribution

random assignment

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

random sampling

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

random selection

Procedure that ensures every person in a population has an equal chance of being chosen to participate

regression toward the mean

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

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.

representative sample

The selection of study units (e.g., participants, homes, schools) from a larger group (population) in an unbiased way, such as that the sample obtained accurately reflects the total population.

scatterplot

A graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of spread suggests the strength of the correlation (little spread indicates high correlation).

self-report bias

Inaccuracies or distortions in responses to surveys or questionnaires due to factors such as social desirability, memory recall, or misunderstanding of questions.

single-blind study

Research design in which participants don't know whether they are in the experimental or control group.

situational variables

Factors related to the experimental setting and are typically controlled by standardizing procedures. Keeping everything the same for each participant in both groups except for the independent variable

skewed distribution

A representation of scores that lack symmetry around their average value

social desirability bias

A tendency to give socially approved answers to questions about oneself.

standard deviation

A measure of how much scores vary around the mean score

statistical significance

A statement of how likely it is that an obtained result occurred by chance. Often set at $p < .05$

stratified sampling

Created by dividing the population into subgroups to create a sample that contains members of each subgroup in the same proportion that exists in the larger population.

survey

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