Chapter 6: Validity Flashcards
Validity
Used in conjunction with the maningfulness of a test score; what the test score truly means; judgment or estimate of how well a test measure what it purports to measure in a particular context
Inference
Logical result or deduction
Valid Test
The test has been shown to be valid for a particular use with a particular population of testtakers at a particular time; Validity is within reasonable boundaries of a comtemplated usage
Validation
Process of gathering and evaluating evidence about validity; both the test developer and the test user may play a role in the validation of a test for a specific purpose
Local Validation Studies
May yield insights regarding a particular population of testtakers as compared to the norming sample described in a test; necessary when the test user plans to alter in some way the format, instructions, language, or contest of the test;
How Validity is Conceptualized
Content Validity
Criterion-Related Validity
Construct Validity
Trinitarian View of Validity
Construct validity is the umbrella validity;
Approaches to assessing validity
Content Validity
Criterion-related Validity
Construct Validity
Approaches to Assessing Validity
Scrutinize the test’s content
Relate scores obtained on the test to other test scores or other measures
Executing a comprehensive analysis of
How the scores on the test relate to other test scores and measures
How scores on the test can be understood within some theoretical framework for understanding the construct that he test was designed to measure
Face Validity
Relates more to what a test appears to measure to the person being tested than to waht the test actually measures; face validity is a judgment concerning how relevant the test items appear to be
High Face Validity
If it appears to measure what it purports to measure what it purports to measure on the face of it
Lack of Face Validity
Contributes to a lack of confidence in the perceived effectiveness of the test - with a consequential decrease in the testtaker’s cooperation or motivation to do his or her best
Content Validity
Describes a judgment of how adequately a test samples behavior representative of the universe of behavior that the test was designed to sample
Test Blueprint
Emerges for the structure of the evaluation; a plan regarding the types of information to be covered by the items, the number of items tapping each area of coverage, the organization of the items in the test, and so forth; represents the culmination of efforts to adequately sample the universe of content areas that conceivably could be sampled in such a test
Lawshe Test
A method for gauging agreement among raters or judges regarding how essential a particular problem is
C.H. Lawshe
Proposed that each rater repond to the following querstion for each item: Is the skill or knowledge measured by this item:
Essential
Useful But not Essential
Not Necessary
Content Validity Ratio
Negative CVR - when fewer than half the panelists indicate essential, the CVR is negative
Zero CVR - when exactly half the panelists indicate essential, the CVR is Zero
Positive CVR - when more than half but not all the panelists indicate essential, the CVR ranges between .00 to .99
Criterion-Related Validity
Judgment of how adequately a test score can be used to infer an individual’s most probably standing on some measure of interest-the measure of interest being the criterion
Types of Validity Evidence under Criterion-Related Validity
Concurrent Validity
Predictive Validity
Concurrent Validity
An index of the degree to which a test score is related to some criterion measure obtained at the same time (concurrently)
Predictive Validity
An index of the degree to which a test score preducts some criterion measure
Characteristics of a Criterion
Relevant
Valid
Uncontaminated
Criterion Contimination
Term applied to a criterion measure that has been based, at least in part, on predictor measures
Concurrent Validity
When test scores obtained at about the same time that the criterion measures are obtained, then the measures of the relationship between test scores and the criterion provide evidence of concurrent validity
Predictive Validity of a Test
Indicated when measures of the relationship between the test scores and a criterion measure obtained at a future time are measured; how accurately scores on the test predict some criterion measure
Criterion-Related Validity Based on
Validity Coefficient
Expectancy Data
Validity Coefficient
Correlation coefficient that provides a measure of the relationship between test scores and scores on the criterion measure; affected by restriction or inflation of range; should be high enough to result in the identification and differentiation of testtakers with respect to target attributes
Pearson Correlation Coefficient
Used to determine the validity between two measures
Restriction
Whether the range of scores employed is appropriate to the objective of the corelational analysis
Attrition in number of subjects may occur over the course of the study and the validity coefficient may be adversely affected
Incremental Validity
The degree to which an additional predictor explains something about the criterion measure that is not explained by predictors already in use
Expectancy Data
Provide information that can be used in evaluating the criterion-related validity of a test
Expectancy Table
Shows the percentage of people within specified test score intervals who subsequently were placed in various categories of the criterion; may be created from a scattergram according to the steps listed
Taylor-Russell Tables
Provide an estimate of the extent to which inclusion of a particular test in the selection system will actually improve selection; determining the increase over current procedures
Selection Ratio
Numerical value that reflects the relationship between the number of people to be hired and the number of people available to be hired
Base Rate
Refers to the percentage of people hired under the existing system for a particular position
Steps to Create an Expectancy Table
Draw a scatterplot such that each point in the plot represents a particular test score-criterion score combination; Criterion on Y axis
Draw grid lines in such a way as to summarize the number of people who scored within a particular interval
Counter the number of points in each cell (n)
Count the total number of points within each Vertical interval, this number represents the number of people scoring within a particular test score interval
Convert each cell frequency to a percentage; this represents the percentage of people obtaining a particular test score-criterion score combination; write percentages in the cells; enclose the percentages in parentheses to distinguish them from the frequencies
On a separate sheet, create table headings and subheadings and copy the percentages into the appropriate cell tables
If desired, write the number and percentage of cases per test-score interval; if the number of cases in any one cell is small, it is more likely to fluctuate in subsequent charts; if cell sizes are small, the user could create fewer cells or accumulate data over several years