Research Methods and Statistics Vocabulary

Vocabulary flashcards defining key psychological research methods and statistical terms covering Chapters 1 through 5.

Qualitative research

A research method that relies on in-depth narrative data that are not translated into numbers.

Quantitative research

A research method that relies on quantifiable numerical data.

Likert scale

A questionnaire used to gather numerical data where responses fall on a continuum, such as from strongly disagree to strongly agree.

Institutional review

A process where a board of at least five people within a university screens research proposals to make sure they adhere to ethical guidelines.

Informed consent

Giving potential participants enough information about a study to enable them to choose whether they wish to participate.

Informed ascent

A process through which a parent/guardian gives permission for a minor to participate in psychological research.

Protect from harm

The idea that experiments must guard the physical and psychological well-being of their research participants.

Confidentiality

The idea that experiments should not share identifying personal information about their research participants.

Research confederate

A person playing a role within a research experiment, but who is not the focus of the researcher's observation.

Debriefing

The post experimental explanation of a study, including its purpose and any deception to its participants.

Experiment

A research method in which an investigator manipulates one or more factors to observe the effects on some behavior or mental process.

Experimental group

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

Control group

In an experiment, the group not exposed to the treatment serves as a comparison group for evaluating effects of the treatment.

Independent variable

In an experiment, the factor that is manipulated, the variable whose effect is being studied.

Dependent variable

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

Random assignment

Assigning participants to experiment and control groups by chance, thus minimizing the preexisting differences between the different groups.

Single blind procedure

An experiment procedure in which the researcher participants are unaware whether they have received the treatment or placebo.

Double blind procedure

An experiment procedure in which both the research participants and the research staff are unaware of whether the participants have received the treatment or a placebo.

Placebo

An inert substance or condition which the recipient assumes is an active agent.

Placebo effect

Experimental results caused by expectation alone when a participant shows reaction to the placebo.

Confounding variable

In an experiment, a factor other than a factor being studied that may influence a study's results.

Experimenter bias

Errors in research caused when researchers may unintentionally influence results to confirm their own beliefs.

Descriptive statistics

Numerical data used to measure and describe characteristics of groups includes measures of central tendency and measures of variation.

Histogram

A bar graph depicting a frequency distribution.

Measure of central tendency

The way to describe an average within a dataset.

Mean

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

Median

The middle score in a distribution half of the scores are above it, half are below it.

Mode

The most frequently occurring scores in a distribution.

Percentile rank

The percentage of scores that are lower than a given score.

Skewed distribution

A representation of scores that lack symmetry around the average value, where scores cluster more towards one end (positive skew) or the other end (negative skew) of the range.

Bimodal distribution

A data distribution within two peaks around which the scores cluster.

Measures of variation

Numerical ways to describe how far away an individual data points are from the mean within a dataset, including the range and standard deviation.

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

A symmetrical bell shaped curve that describes the distribution of many types of data, where most scores fall near the mean, and fewer scores lie near the extremes.

Inferral statistics

Numerical data that allows one to generalize, to infer from the sampling data the probability of something being true of a population.

Meta analysis

A statistical procedure for analyzing the results of multiple studies to reach overall conclusions.

Statistical significance

A statistical statement of how likely it is that a result occurred by chance assuming there is no difference between the populations being studied.

Effect size

The strength of the relationship between two variables describing how much one variable is affected by the other variables.