Business Research Chapter 13

Index Measures

-Assign a value based on how much of the concept being measured is associated with an observation. -Indexes often are formed by putting several variables together.

1) Nominal

-Assigns a value to an object for identification or classification purposes. -Most elementary level of measurement.

Coefficient alpha (α)

-The most commonly applied estimate of a multiple item scale's reliability. -Represents the average of all possible split-half reliabilities for a construct.

Convergent Validity

Another way of expressing internal consistency; highly reliable scales contain convergent validity.

Constructs

Concepts measured with multiple variables.

Construct Validity

Exists when a measure reliably measures and truthfully represents a unique concept.

Sensitivity

-A measurement instrument's ability to accurately measure variability in stimuli or responses. -Generally increased by adding more response points or adding scale items.

Test-retest Method

-Administering the same scale or measure to the same respondents at two separate points in time to test for stability. -Represents a measure's repeatability.

3) Interval

-Capture information about differences in quantities of a concept. -Have both nominal and ordinal properties.

4) Ratio

-Highest form of measurement. -Have all the properties of interval scales with the additional attribute of representing absolute quantities. -Absolute zero.

Establishing Validity:

-Is there a consensus that the scale measures what it is supposed to measure? -Does the measure correlate with other measures of the same concept? -Does the behavior expected from the measure predict actual observed behavior?

2) Ordinal

-Ranking scales allowing things to be arranged based on how much of some concept they possible. -Have nominal properties.

Internal Consistency

-Represents a measure's homogeneity or the extent to which each indicator of a concept converges on some common meaning. -Measured by correlating scores on subsets of items making up a scale.

Validity

-The accuracy of a measure or the extent to which a score truthfully represents a concept. -Does a scale measure what was intended to be measured?

Reliability

-The degree to which measures are free from random error and therefore yield consistent results. -An indicator of a measure's internal consistency.

Problems

-The pre-measure, or first measure, may sensitize the respondents and subsequently influence the results of the second measure. -Time effects that produce changes in attitude or other maturation of the subjects.

Scales

A device providing a range of values that correspond to different characteristics or amounts of a characteristic exhibited in observing a concept.

Concept

A generalized idea about a class of objects, attributes, occurrences, or processes

Summated Scale

A scale created by simply summing (adding together) the response to each item making up the composite measure.

Face Validity

A scale's content logically appears to reflect what was intended to be measured.

Split-half Method

Assessing internal consistency by checking the results of one-half of a set of scaled items against the results from the other half.

Composite Measures

Assign a value to an observation based on a mathematical derivation of multiple variables.

Correspondence rules

Indicate the way that a certain value on a scale corresponds to some true value of a concept.

Reverse Coding

Means that the value assigned for a response is treated oppositely from the other items.

Discrete Measures

Measures that can take on only one of a finite number of values.

Continuous Measures

Measures that reflect the intensity of a concept by assigning values that can take on any value along some scale range.

Discriminant Validity------

Represents how unique or distinct is a measure; a scale should not correlate too highly with a measure of a different construct.

Attributes

Single characteristics or fundamental features that pertain to an object, person, or issue.

Criterion validity

The ability of a measure to correlate with other standard measures of similar constructs or established criteria.

Content Validity

The degree that a measure covers the breadth of the domain of interest.

Measurement

The process of describing some property of a phenomenon, usually by assigning numbers in a reliable and valid way.

Operationalization

The process of identifying scales that correspond to variance in a concept involved in a research process.