
An organized process for collecting knowledge
Research

A group of logically related statements that explains things that have occurred in the past and predicts things that will occur in the future.
Theory

A set of steps followed by scientists to ensure a common basis for conducting research.
Scientific Method

Research in which no manipulation of variables is involved an no causeandeffect relationship is studied.
Nonexperimental Research

Research that describes the characteristics of a phenomenon without attempting to determine what causes the phenomenon.
Descriptive Research

A method of research used to determine relationships between two or more variables.
Correlational Research

Research that examines phenomena within the cultural and social context in which it takes place.
Qualitative Research

Research in which a cause and effect is unambiguously tested.
True Experimental Research Method

Research that is done when groups are preassigned to "treatments," such as gender, social class, and neighborhood, also known as Post Hoc Research.
QuasiExperimental Research

Research that examines causeandeffect relationships through the use of control and treatment groups.
Experimental Research Methods

The method and structure of an investigation chosen by the researcher to conduct data collection and analysis.
Research Design

Pure research which adds to the base of information in a field but has no immediate application.
Basic Research

Research that has an immediate application at the time it is completed.
Applied Research

Represents a class of outcomes that can take on more than one value.
Variable

Assignment of values to objects, events, or outcomes according to rules
Measurement

The measure that reflects the outcomes of a research study
Dependent Variable

A variable controlled by the researcher in an attempt to test the effects on some outcome, the dependent variable.
Independent Variable/ Treatment Variable

A research design in which more than one independent variable is studied in various combinations with others.
Factoral Designs

When variables compete to explain the effects found in a study.
Confounding

A variable that has a potential influence on the dependent variable.
Control Variable

A variable that has an unpredictable impact upon the dependent variable
Extraneous Variable

A variable that is related to the variables of interest (such as the dependent and independent variable), masking the true relationship between the independent and dependent variable.
Moderator Variable

A statement of equality between groups in an investigation; the state of affairs that is accepted as true in the absence of other information. A starting point for observing the effects of the independent variable(s) on the dependent variable and as a benchmark for the comparison of chance versus significant differences between groups.
Null Hypothesis

A statement of inequality between groups in an investigation. Suggestion of directional or nondirectional relationships between groups.
Research Hypothesis

A research hypothesis that posts an inequality (such as a difference between groups) but makes no suggestion of the direction of that difference (such as more than or less than).
Nondirectional Research Hypothesis

A research hypothesis that posits an inequality between groups with direction to that difference (such as more than or less than).
Directional Research Hypothesis

The entirety of some group
Population

A representative portion of a population
Sample

The ability to draw inferences and conclusions from data
Generalizability

The degree of risk you are willing to take that you will reject a null hypothesis when it is actually true
Statistical Significance

The amount of risk one is willing to take that the null hypothesis is true even though it is rejected.
Significance Level

General information usually available through newspapers
General Sources

Secondhand sources of historical data, such as newspaper clippings and summary statistics
Secondary Resources

People or documentation, which presents firsthand information.
Primary Sources

A brief summary of journal article which appears before the actual article or in a collection of abstracts.
Abstract

Consistency in performance or prediction
Reliability

The most frequently occurring score
Mode

The most frequently occurring score
Variance

The score at which 50% of the scores in the distribution fall above it and 50% fall below it.
Median

The extent to which the results of an experiment can be generalized.
External Validity

The sum of all the scores in a distribution divided by the number of observations.
Mean

The accuracy in concluding that the outcome of an experiment is due to the independent variable.
Internal Validity

The distance between the highest and lowest score in a distribution.
Range

Average distance of each score in a distribution from the mean.
Standard Deviation

The truthfulness or accuracy within the score of a test or interpretation of an experiment.
Validity

The type of sampling used when the likelihood of selecting any one member of the population is known
Probability Sampling

When the likelihood of selecting any one member of the population is unknown.
Nonprobability Sampling

A sampling procedure allowing for the equal and independent chance of subjects being selected as part of the sample.
Simple Random Sampling

An unbiased criterion used in the selection of subjects for a sample.
Table of Random Numbers

A random sampling procedure in which increments determine who becomes part of the sample; for example, every third person is selected.
Systematic Sampling

The process of selecting a sample that represents different groups or levels of a population.
Stratified Sampling

A random sampling procedure used when subjects are known to be unequal on some variable in the population.
Stratified Random Sampling

A probability sampling procedure wherein units of subjects are selected, rather than the subjects themselves.
Cluster Sampling

A nonprobability sampling procedure wherein the selected sample represents a captive audience; for example, sophomore college students in an introductory psychology class.
Convenience Sampling

A nonprobability sampling procedure similar to stratified random sampling in that a particular stratum is the focus; however, a specified number is set to be selected, and once that number is met, no further selection occurs.
Quota Sampling

A stratified random sampling procedure wherein subjects in the sample are selected in proportion to how they are represented in the population.
Proportional Stratified Sampling

The magnitude of the difference between the characteristics of the sample and the characteristics of the population from which it was selected.
Sampling Error

procedures that allow inferences to be made from a sample to the population from which the sample was drawn
Inferential Sampling

The scale representing a hierarchy of precision on which a certain type of variable might be assessed.
Level of Measurement

Measurement that assigns labels that do not suggest quantity
Nominal level of Measurement

measurement that assigns only rank order to outcome.
Ordinal Level of Measurement

measurement that assigns values representing equal distances between points but that does not allow for proportional comparisons.
Interval Level of Measurement

measurement that allows for proportional comparison and a meaningful zero.
Ratio Level of Measurement

a variable that has an underlying continuum that can take on any value.
Continuous Variable

a variable that can take on one of several mutually exclusive values.
Discrete or Categorical Variable

consistency in performance or prediction.
Reliability

True score plus error score
Observed Score

The actual score for someone on some test.
True Score

The part of an individual’s observed score that is attributable to method or trait variance or error.
Error Score

the part of an individual’s error score that is due to characteristics of the test or test taking situation
Method Error

the part of an individual’s error score that is attributable to characteristics of the individual
Trait Error

an index of the strength of a relationship between two variables. It ranges in value from 1.00 to 1.00. it can be positive or negative
Correlation Coefficient

numerical index of the relationship between a set of variables
Reliability coefficient

a measure of how stable a test is over time.
Testretest reliability

examines consistency between forms. The relationship of two tests made from the same pool of items.
Parallelforms reliability (aka Equivalence)

a measure of the consistency from rater to rater. Consistency of results produced by the same test given by different people
Interrater reliability

examines how unified the items are in a test or assessment. A measure of reliability which examines the unidimensional nature of a test
Internal consistency

indicates the extent to which a test represents the universe of items from which it is drawn. The extent to which a test fairly represents the universe of all possible questions that might be asked
Content Validity

how well a test estimates (concurrent validity) or predicts (predictive validity) performance outside of the testing situation; a measure of the extent to which a test is related to some criterion
Criterion Validity

the extent to which the results of a test are related to an underlying psychological construct. The extent to which a test truly measures a proposed psychological ability of skill and is related to an underlying theory or model of behavior
Construct Validity

various traits are measured using various methods. Regardless of how they are measured the scores are related. Thus, if the same trait is measured using different methods, the scores should be related, and if different traits are measured using the same methods, the scores should not be related.
Multitraitmultimethod matrix

a component of construct validity in which method variance is shared when measuring the same traits.
Convergent validity

a component of construct validity in which trait variance is shared when using the same method.
Discriminant Validity

test used to measure knowledge of a specific area
Achievement tests

tests with standard instructions and scoring procedures which are used for all administrations of the test. One type of achievement test
Standardized tests

Tests designed for a specific purpose with specific scoring and instructions for that purpose. One type of achievement test.
Researcher/Teachermade tests

tests allowing you to compare individual’s test performance to the test performance of other individuals. A test in which the individual’s performance is compared with the results of a larger group of peers.
Normreferenced tests

tests defining a specific criterion or level of performance, and the only thing of importance is the individual’s performance, regardless of where that performance might stand in comparison with others. A test measures mastery of specific definitions of performance for an individual in a particular content domain.
Criterionreferenced tests

a process of evaluating multiple choice items by using difficulty level and the ability of the item to discriminate or differentiate between group performance
Item analysis

the proportion of test takers who got the multiple choice item correct.
Difficulty Index (D)

an index that describes how well a multiple choice item differentiates between high scores and low scores on a test
Discrimination Index (d)

tests which assess an individual’s feelings about an object, person, or event
Attitude tests

a method of measuring attitudes. A method used in constructing attitude tests in which all of the items are assigned an attitude score. It is made up of nearly equal intervals for individuals to agree or disagree with various statements
Thurston Scale

Thurston Scale
Method of equal appearing intervals

a method used in attitude scales that requires the individual to agree or disagree to a set of statements using a fivepoint scale
Likert Scale

Likert Scale
Method of summated ratings

tests assessing stable individual behavior patterns
Personality tests

personality tests that ask the participant to respond to an ambiguous stimulus. It is assumed that the participant will project their worldview onto the stimulus.
Projective tests

interview questions that have a clear and apparent focus and a clearly called for answer (closeended questions)
Structured tests

the researcher uses a device to keep track of time and measures the length of time that a behavior occurs. Recording behavior based on the amount of time it lasts.
Duration recording

Recording behavior based on the incidence or frequency of the occurrence of a particular behavior
Frequency Recording

a particular subject is observed/recorded during a particular interval of time
Interval recording/time sampling

all of the behavior of the target subject is recorded, with little concern as to the specificity of its content. Recording behavior on a continuous basis.
Continuous recording

Each score for each individual on a test or in an experiment.
Data Points

data that are unorganized
Raw Data

A form used to record raw data and often used to facilitate entry in to the computer.
Data Collection Form

A specially printed scoring sheet that can be read and scored by computer.
Optical Scoring Sheet

A special computer that reads optical scoring sheets
Optical Scanner

using numbers to represent data
Coding

Simple measures of a distribution’s central tendency and variablility.
Descriptive Statistics

Set of tools to help you make decisions about how the data you collected relate to your original hypotheses and how they might be generalizable to a larger number of subjects than those who were tested. Procedures that allow inferences to be made from a sample to the population from which the sample was drawn.
Inferential Statistics

The general shape of data which includes a mean, median, and mode
Distribution scores

measures of central tendency represented as the mean, median, or mode.
Measures of central tendency

scores that have the same reference point and the same standard deviation. Scores that have been derived to create a common reference point and the same standard deviation to allow for easy comparison.
Standard Scores

It is the occurrence of variability which cannot be accounted for by any of the variables that you are studying. The unassuming explanation for differences between groups that implies that the differences are accounted for by variables other than those being studied.
Chance

dictates that regardless of the shape of the distribution (be it normal or not), the means of all the samples selected from the population will be normally distributed. The theorem in inferential statistics which states that regardless of the shape of the population distribution, repeated samples from it will produce means that are normally distributed
Central limit theorem

Same as statistical significance
Type I Error

Inadvertent acceptance of a false null hypothesis. The acceptance of a false null hypothesis. The probability that a Type II error will occur can be reduced by increasing the size of the sample.
Type II error

The application of a statistical procedure to determine whether observed differences exceed the critical value, indicating that chance is not the most attractive explanation for the results.
Test of statistical significance

computation of the test statistic value. The value obtained by applying a statistical test of significance.
Obtained value

the minimum value you would expect the test statistic to yield if the null hypothesis is indeed false. The tabled value at which point the null hypothesis cannot be accepted; the minimum value you would expect the test statistic to yield if the null hypothesis is true.
Critical value

The leeway for variation a statistical value has; they help determine the critical value of the test statistic; a reflection of the sample size.
Degrees of freedom

an advanced technique that examines whether group differences occur for more than one dependent variable. Statistical procedures used to examine group differences that occur on more than one dependent variable.
Multivariate analysis of variance MANOVA

an advance technique that allows the researcher to reduce the number of variables that represent a particular construct and then use factor scores as dependent variables. An advanced statistical technique that allows for the reduction of variables representing a particular construct and then uses factor scores as dependent variables.
Factor analysis

a procedure that allows for the examination of trends and patterns that may exist in many different groups in many different studies.
Metaanalysis

The notion that the stronger the effects of a treatment, the smaller the required sample size.
Effect size

“Sample surveys” examine the frequency and relationships between psychological and sociological variables and taps into constructs such as attitudes, beliefs, prejudices, preferences, and opinions.
Survey Research

Basic tool in survey research. A method of collecting data that is similar to an oral questionnaire. An interview can be informal and flexible or structured and focused
Interview

Neutral information about the respondent (age, living arrangements…).
Facesheet information

Questions have a clear and apparent focus and call for an explicit answer. Interview questions that have a clear and apparent focus and a clearly called for answer.
Structured/Closeended questions

Questions allow the interviewee to elaborate upon responses. Interview questions that provide a broad opportunity for the participant to respond.
Unstructured/Openended questions

a general plan for survey research of what activities will occur when.
Flow plan

When the interviewer subtly biases the respondent to respond in one way or another. Bias introduced when the interviewer subtly influences the interviewee’s responses.
Interviewer bias

describes the linear relationship between two or more variables without any hint of attributing the effect of one variable on another. A method of research used to determine relationships between two or more variables.
Correlational Research

an index of the relationship between variables.
Pearson product moment correlation (Pearson’s r)

A plot of scores or data points which indicates the relationship between variables.
Scattergram

the squared correlation coefficient, which indicates the amount of variance in one variable that is accounted for by the other.
Coefficient of Determination

the portion of unexplained variance. The amount of variance that is unaccounted for in the relationship between variables
Coefficient of Alienation

methods of research that examine changes over time
Developmental Research

receives treatment
Experimental Group

does not receive treatment
Control Group

QuasiExperimental Designs
CausalComparative Designs

not characterized by random selection of participants from a population, nor do they include a control group. Research designs that are characterized by a lack of random selection and assignment
PreExperimental Designs

A type of experimental design in which one group receives only one test
Oneshot Case Study

A type of experimental design in which one group receives both a pretest and posttest.
Onegroup Pretest Posttest Design

a true experimental design with a high degree of internal validity.
Pretest posttest control group design

a true experimental design with a high degree of internal validity in which posttests are the only measures taken
Posttestonly Control Group Design

a traditional experimental design in which there are four different groups of participants, and many different questions can be answered simultaneously with some relatively simple comparisons.
Solomon fourgroup Design

if what you see is a function of what you did…
Internal Validity

the quality of an experimental design such that the results can be generalized from the original sample to another sample and then, by extension, to the population from which the sample originated.
External Validity

a statistical tool that equalizes any initial differences that might exist.
Analysis of covariance (ANCOVA)

A preexperimental design in which groups are not equivalent at the beginning of the research and which generally lacks a suitable degree of internal validity. One of the most commonly used quasiexperimental designs.
Nonequivalent control group design

A preexperimental design with limited internal validity. It is similar to nonequivalent control group design except there is no pretest
Static group comparison design

Observing one subject over a variety of behaviors… allow for an indepth examination of specific behaviors.
Singlesubject research design

Level of behavior associated with a subject before an experiment begins
Baseline

Methods of research that examine changes over time.
Developmental Research

assess changes in behavior in one group of subjects at more than one point in time; A method of developmental research that assess changes in behavior in one group of subjects at more than one point in time.
Longitudinal Method

examines several groups of people at one point in time; a method of developmental research used to examine age differences rather than age changes
Crosssectional method

