Data Collections Module 3

Alternate-forms reliability

A procedure for testing the reliability of responses to survey questions in which subjects’ answers are compared after the subjects have been asked slightly different versions of the questions or when randomly selected halves of the sample have been administered slightly different versions of the questions.

Closed-ended (fixed-choice) question

A survey question that provides preformatted response choices for the respondent to circle or check.

Concept

A mental image that summarizes a set of similar observations, feelings, or ideas.

Conceptualization

The process of specifying what we mean by a term. In deductive research, conceptualization helps translate portions of an abstract theory into testable hypotheses involving specific variables. In inductive research, conceptualization is an important part of the process used to make sense of related observations.

Constant

A number that has a fixed value in a given situation; a characteristic or value that does not change.

Construct validity

The type of validity that is established by showing that a measure is related to other measures as specified in a theory.

Content analysis

A research method for systematically analyzing and making inferences from text.

Criterion validity

The type of validity that is established by comparing the scores obtained on the measure being validated to those obtained with a more direct or already validated measure of the same phenomenon (the criterion).

Exhaustive

Every case can be classified as having at least one attribute (or value) for the variable.

Face validity

The type of validity that exists when an inspection of items used to measure a concept suggests that they are appropriate “on their face.”

Index

A composite measure based on summing, averaging, or otherwise combining the responses to multiple questions that are intended to measure the same concept.

Interitem reliability (internal consistency)

An approach that calculates reliability based on the correlation between multiple items used to measure a single concept.

Interobserver reliability

When similar measurements are obtained by different observers rating the same persons, events, or places.

Interval level of measurement

A measurement of a variable in which the numbers indicating a variable’s values represent fixed measurement units but have no absolute, or fixed, zero point.

Level of measurement

The mathematical precision with which the values of a variable can be expressed. The nominal level of measurement, which is qualitative, has no mathematical interpretation; the quantitative levels of measurement—ordinal, interval, and ratio—are progressively more precise mathematically.

Mutually exclusive

A variable’s attributes (or values) are mutually exclusive when every case can be classified as having only one attribute (or value).

Nominal level of measurement

Variables whose values have no mathematical interpretation; they vary in kind or quality but not amount.

Open-ended question

A survey question to which the respondents reply in their own words, either by writing or by talking.

Operation

A procedure for identifying or indicating the value of cases on a variable.

Operationalization

The process of specifying the operations that will indicate the value of cases on a variable.

Ordinal level of measurement

A measurement of a variable in which the numbers indicating a variable’s values specify only the order of the cases, permitting greater than and less than distinctions.

Ratio level of measurement

A measurement of a variable in which the numbers indicating the variable’s values represent fixed measuring units and an absolute zero point.

Reliability

A measurement procedure yields consistent scores when the phenomenon being measured is not changing.

Scale

 A composite measure based on combining the responses to multiple questions pertaining to a common concept after these questions are differentially weighted, such that questions judged on some basis to be more important for the underlying concept contribute more to the composite score.

Split-halves reliability

Reliability achieved when responses to the same questions by two randomly selected halves of a sample are about the same.

Test–retest reliability

A measurement showing that measures of a phenomenon at two points in time are highly correlated, if the phenomenon has not changed or has changed only as much as the phenomenon itself.

Triangulation

The use of multiple methods to study one research question.