Glossary
 Applied Research

Research carried out for practical applications and problemsolving functions.
 Attitude Measurement

An attitude measurement survey is a study, on a properly drawn sample, of a specified population to find out what people in that population feel about a specified issue.
 Basic Research

Research carried out to discover something simply for the sake of knowledge to improve our
understanding of the world, and for academic rather than commercial purposes.  categorical variable

variables that take on values that are names or labels
 Conceptual Research

Research that is used to educate policymakers and stakeholders on social issues and propose possible solutions.
 concurrent validity

A type of Criterion validity. Examines how well a tool provides the same scores as an already existing tool.
 Construct Validity

seeks an agreement between a theoretical concept and a specific measuring device, such as observation.
 Constructs

re not observable but can be defined based on observable characteristics
 Content Validity

The extent to which a measure “covers” the construct of interest, i.e., it's comprehensiveness to measure the construct.
 Control Group

a group in a randomized experiment that receives an inactive treatment but is otherwise managed exactly as the other groups
 Criterion

A variable that theoretically should be correlated with the construct being measured (plural: criteria).
 Criterion Validity

The extent to which people’s scores on a measure are correlated with other variables (known as criteria) that one would expect them to be correlated with.
 data

a set of observations (a set of possible outcomes); most data can be put into two groups: qualitative (an attribute whose value is indicated by a label) or quantitative (an attribute whose value is indicated by a number). Quantitative data can be separated into two subgroups: discrete and continuous. Data is discrete if it is the result of counting (such as the number of students of a given ethnic group in a class or the number of books on a shelf). Data is continuous if it is the result of measuring (such as distance traveled or weight of luggage)
 Descriptive research

research that describes or defines a particular phenomenon
 Empirical Research

The process of developing systematized knowledge gained from observations that are formulated to support insights and generalizations about the phenomena being researched.
 evaluation research

research that evaluates the outcomes of a policy or program
 Experiment

an operation or procedure carried out under controlled conditions in order to discover an unknown effect or law, to test or establish a hypothesis, or to illustrate a known law.
 experimental unit

any individual or object to be measured
 explanatory variable

the independent variable in an experiment; the value controlled by researchers
 Exploratory Research

Conducted during the early stages of a project, usually when a researcher wants to test the feasibility of conducting a more extensive study or if the topic has not been studied in the past
 External Validity

This is a synonymous term for generalizability  the ability to apply the findings of a study beyond the sample to a broader population.
 Face Validity

The extent to which a measurement method appears “on its face” to measure the construct of interest
 Focus group

a research tradition involving interview data collected in a group setting (rather than from individual participants).
 frequency

the number of times a value of the data occurs
 independent variables

the variable in a study design presumed or hypothesized to vary on its own, but that determines variation observed in the dependent (outcome or output) variable; the “input” variable in a study design (i.e., usually denoted as the “x” variable, where “y” denotes the dependent variable).
 Interaction Variables

A variable constructed from an original set of variables to try to represent either all of the interaction present or some part of it.
 Internal Consistency

the extent to which all questions or items assess the same characteristic, skill, or quality.
 Internal Validity

Ability to say that one variable "causes" something to happen to another variable. Very important to assess when thinking about studies that examine causation such as experimental or quasiexperimental designs.
 Interval Scale

A higher level of measurement. Denoted by having mutually exclusive categories, a hierarchy (order), and equal spacing between values. This last item means that values may be added, subtracted, divided, and multiplied.
 latent variable

a variable not directly observed but mathematically or statistically inferred from other variables that are directly measured.
 Longitudinal Research

study design where data are collected repeatedly from the same individuals/elements/units over time.
 Measurement

The process by which we describe and ascribe meaning to the key facts, concepts, or other phenomena that we are investigating.
 Multiple regression

regression model used to find an equation that best predicts the YYvariable as a linear function of multiple XX variables
 Nominal Scale

level of measurement that is categorical and those categories cannot be mathematically ranked, though they are exhaustive and mutually exclusive
 Nominal variables

another name for categorical variables (categories have names, are not numeric)
 Null Hypothesis

A hypothesis set up to be refuted in order to support an alternative hypothesis; presumed true until statistical evidence in the form of a hypothesis test indicates otherwise.
 Ordinal Scale

Level of measurement that follows nominal level. Has mutually exclusive categories and a hierarchy (order).
 ordinal variables

categories of a variable have numeric relationships, can be sequenced in numeric order but are not continuous interval variables (for example, ratings of frequency from never to always)
 parameter

a number that is used to represent a population characteristic and that generally cannot be determined easily
 Partial Regression Coefficients

a value indicating the effect of each independent variable on the dependent variable with the influence of all the remaining variables held constant. Each coefficient is the slope between the dependent variable and each of the independent variables
 Polynomial Regression

a higher order form of linear regression in which the relationship between the independent variable xxand the dependent variable yy is modeled as an nnth order polynomial
 population

all individuals, objects, or measurements whose properties are being studied
 predictive validity

A type of criterion validity that examines how well your tool predicts a future criterion.
 primary data

data collected with the intention of meeting aims of the specific research study for which the data are collected.
 probability

a number between zero and one, inclusive, that gives the likelihood that a specific event will occur
 probability sampling

selecting research participants using methods that ensure every member of the original population has an equal chance (probability) of being selected; (see random selection).
 proportion

the number of successes divided by the total number in the sample
 Qualitative Research

Empirical research in which the researcher explores relationships using textual, rather than quantitative data. Case study, observation, and ethnography are considered forms of qualitative research. Results are not usually considered generalizable, but are often transferable.
 qualitative variable

Also known as categorical variable has no natural sense of ordering; takes on names or labels.
 Quantitative Research

Empirical research in which the researcher explores relationships using numeric data. Survey is generally considered a form of quantitative research. Results can often be generalized, though this is not always the case.
 Quasi Experiments

a subtype of experimental design that is similar to a true experiment, but does not have randomly assigned control and treatment groups
 random assignment

the act of organizing experimental units into treatment groups using random methods
 Random Error

Errors lack any perceptable pattern.
 Ratio Scale

The highest level of measurement. Denoted by mutually exclusive categories, a hierarchy (order), values can be added, subtracted, multiplied, and divided, and the presence of an absolute zero.
 Reliability

The ability of a measurement tool to measure a phenomenon the same way, time after time. Note: Reliability does not imply validity.
 sample

a subset of the population studied
 Scales

a composite measure designed in a way that accounts for the possibility that different items on an index may vary in intensity (5.3)
 Secondary data

research using data originally collected for a different research purpose (a secondary use of the data).
 statistic

a numerical characteristic of the sample; a statistic estimates the corresponding population parameter.
 statistical models

a description of a phenomenon using probability distributions that describe the expected behavior of the phenomenon and the variability in the expected observations.
 survey

a study in which data is collected as reported by individuals.
 Systematic errors

Errors that are generally predictable.
 Validity

The extent to which the scores from a measure represent the variable they are intended to.
 Variables

refers to a grouping of several characteristics