A
Guide to Test Validation
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P
A G E & AS
S O C I A T E S
Human Resource & Organizational
Consultants |
Hiring the Right
People
Test Validation is critically
important to organizations that wish to identify and hire the best people
for their jobs. It is the key element to creating a high-performance workforce
through hiring the best people for the organization’s needs.
Hiring
the right people directly impacts productivity, quality, customer service
and the bottom-line profitability of the organization. Moreover, bad hiring
decisions can be very costly to the organization. The cost of replacing
employees that have turned over is estimated to be 1½ times annual
salary. This figure includes the costs associated with recruitment, selection,
training and lost productivity while the new hire is learning the job.
The following sections address the
key issues in Test Validation.
What
are Tests?
A test is a standardized sample of
behavior that measures performance on a numerical scale or category system.
As such, it provides an objective means of assessing human performance
and comparing the performance of different individuals. In work settings,
there are different types of tests, including, but not limited to:
-
Selection (pre-employment) tests
— tests that are administered to job applicants prior to being hired.
-
Promotion tests — tests that are
administered to employees who are being considered for promotion.
-
Certification tests — tests that
are administered to individuals who wish to be certified as possessing
a specific level or type of expertise.
Surveys
indicate that between 50% and 90% of US employers are currently using some
form of employment testing. This includes both pre-employment testing and
promotion testing. However, to effectively deploy testing, all organizations
should undertake test validation.
What
is Test Validation?
Test Validation addresses the
extent to which tests actually measure what they are purported to measure.
Do the tests actually identify the most effective employees?
The concept underlying tests is this:
If an individual scores higher in a test than other individuals, then he
or she should be a more effective employee than the other individuals.
To what extent is this true? Is it a valid inference that the higher scorer
will in fact become a more effective employee?
In work settings, Test Validity addresses
the existence and nature of evidence demonstrating that employment tests
assess job relevant behaviors that relate to job performance outcomes.
Why
do Test Validation?
In an era where an organization’s competitive
advantage is achieved through its people, it is important to have highly
effective staff. Organizations need to hire the best candidates. Test Validation
is the process that pinpoints those pre-employment assessment techniques
that identify the best candidates for the organization’s jobs.
There
are three primary reasons for doing a validation study:
-
Defining key success factors —
identifying and defining the key competencies that drive success in the
organization. By knowing precisely what to look for, your chances of hiring
high-performance candidates are greatly increased.
-
Identifying the best candidates
— objectively assessing candidates and assuring that the organization selects
those with superior talent. By selecting the best candidates, you can build
a superior organization.
-
Assuring legal defensibility —
assuring that your hiring process is legally defensible. By following the
prescriptions of the EEOS’s Uniform Guidelines for Employee Selection
Procedures, you can provide documentation for the legal defensibility
of your testing system, if it were to be legally challenged.
What
are the Benefits of Test Validation?
There are several important benefits
from performing a validation study. These include:
-
Precise definition of the competencies
that drive job success — assuring that you can target those behaviors
that truly drive superior performance.
-
Hiring superior talent — because
the most competent candidates are identified through an objective assessment
process.
-
Greater objectivity and fairness in
the job applicant screening process — to assure accurate comparisons
between candidates.
-
Significantly Improved productivity
and profitability — because of reduced errors in selection decisions,
reduced training time and costs, reduced staff turnover, and improved productivity
and effectiveness of workers.
-
Legal defensibility of the employee
selection process — providing peace of mind regarding hiring decisions
and the avoidance of potentially costly litigation.
Validation
Approaches
There are different approaches to validating
tests. The most commonly uses approaches in employment settings include:
-
Content Validation — A technique
that assures that there is overlap in key aspects of job and test content.
Content validity is shown by carrying out a detailed analysis of job content
followed by a matching of this information to test content. If there is
overlap, indicating that test content is directly related to job content,
it is asserted that the test is job related, thus valid.
-
Concurrent Validation — A technique
that demonstrates, for a sample of employees, that there is a significant
relationship between test scores and job performance scores. For a sample
of current employees, test scores are obtained and, concurrent in time,
job performance scores are obtained. Then, the test scores are statistically
correlated with the job performance scores. The resulting correlation coefficient
is an index showing the degree of validity for the tests. This approach
empirically demonstrates that those identified by the tests as likely to
be superior performers are truly superior performers.

-
Predictive Validation — A technique
that demonstrates, between time of hire and a later point in time, that
there is a significant relationship between test scores and job performance.
Typically, job applicants are tested and the test results are not used
in making hiring decisions. Then, at a later point in time, job performance
scores are obtained. The test scores are then correlated with job performance
scores to identify the extent to which the tests predict job performance.
Content
Validity Process
Content validity shows that the content
of the test mirrors important work behaviors of the job. The process involves
an analysis of job content (through job analysis) and information on the
test content. Job content is linked to test content. If there is overlap
between the test content and important aspects of job content, then the
test is determined to be content valid.
Content
validity is a particularly appropriate approach for certain types of knowledge
and skill tests that are designed to be a sample of actual work behaviors.
Examples include tests that assess word processing skills, alphabetical
filing skills, math skills, and knowledge of a job-related technical area.
The process for demonstrating content
validity involves the following steps:
-
Job Analysis. An analysis of job
content is performed to identify the essential responsibilities of the
job and to specify the job competency requirements for job success. This
is accomplished by any of a number of different approaches, which include:
review of job descriptions, review of training materials, interviews with
job holders and supervisors, focus group sessions with subject matter experts
(SMEs), and/or completion of job analysis questionnaires.
-
Identification of job-related tests.
The job content information is matched to tests. Those tests that have
a high degree of overlap with job content and the underlying job competency
requirements are identified as being content valid. Where multiple tests
are identified for a specific skill area, the organization should select
the one test that has the closest match to the job. The test that is closest
to job content in terms of level of difficulty, format of items and scope
of skills assessed should be selected. Additionally, consideration should
be given to selecting tests that are easy to administer in a consistent
way and are fair and equally relevant for diverse applicant group. Often
combinations of different tests are identified, each test assessing a different
aspect of job content. These tests are combined together into a test
battery.

-
Validation Report. A final report
is developed that documents the validity of the testing process. It reports
the results of the job analysis and the matching of job content to test
content. Also, procedures for the implementation of the test battery in
a fair and consistent manner are described. This report has two key purposes:
1) describing how to implement the testing program in an appropriate manner,
and 2) providing legal documentation in the case of a legal challenge to
the use of the testing process.
Concurrent
Validity Process
The concurrent validation process shows
that, for a sample of employees, test scores and job performance scores,
measured concurrently in time, are statistically related. The statistical
measure that is used is the correlation. It measures the degree
of relationship between test scores and job performance scores and has
a range from plus one to minus one.
Positive correlations indicate that
individuals with higher test scores have higher job performance scores.
Correlations of zero indicate that there is no relationship between test
scores and job performance. Negative correlations indicate that people
with higher test scores tend to have lower job performance scores. The
"size" of the correlation shows the degree to which test scores and job
performance scores are related. However, if the magnitude of the correlation
is statistically significant, the test is typically judged to have met
the technical requirements for being valid.
Concurrent
validity is one of the most accepted means of demonstrating test validity.
It is used for all types of tests, including knowledge and skill tests,
but also of tests assessing general mental ability, work styles (i.e.,
personality), and tests that measure abstract constructs that are not effectively
addressed through content validity.
An important prerequisite to undertaking
a concurrent validity study is having a sufficiently large sample. A rule
of thumb is that a minimum of 35 subjects be involved in the study. However,
the larger the sample the better and it is often desirable to have 100
or more subjects. The larger the sample, the greater the accuracy and precision
in asserting the validity of the tests.
A key aspect of the concurrent validity
study is the job performance measures used for employees. These are referred
to as the "criterion measures." For certain jobs these may be objective
measures. For a Data Entry Operator, this may be a measure of the number
of error-free keystrokes per hour. However, for most jobs there is no such
objective measure and supervisor ratings provide the most direct and accurate
measure of job performance.
It is critically important to use accurate
and fair job performance measures. These are typically developed for the
validation study and typically consist of ratings on separate job performance
dimensions. The best rating forms use behavioral descriptors along a scale
for each dimension, what is referred to as behaviorally anchored rating
scales (BARS). These rating scales are typically developed as a part of
the job analysis phase of a concurrent validation study.
The process for demonstrating concurrent
validity involves the following steps:
-
Job Analysis. An analysis of job
content is performed to identify the essential responsibilities of the
job and to specify the job competency requirements for job success. This
is accomplished by any of a number of different approaches, which include:
review of job descriptions, review of training materials, interviews with
job holders and supervisors, focus group sessions with subject matter experts
(SMEs), completion of job analysis questionnaires. Criterion rating scales
are then developed.
-
Identification of job-related tests.
The job content information is matched to tests. Those tests that appear
to most directly relate to the job requirements are selected for inclusion
in the concurrent validity study. This may include skills tests, ability
tests, work styles (personality) tests, etc.

-
Validation Study. A sample of employees
are administered the tests and are assessed in terms of job performance.
Test scores are correlated with job performance scores.
-
Validation Report. A final report
is prepared that documents the validity of the testing process. It reports
the results of the job analysis and the development of the criterion assessments.
It describes the validation study process including the sample, tests,
data collection process, and correlations between test scores and job performance.
Finally, the report documents procedures for the implementation of the
test battery in a fair and consistent manner. This report has two key purposes:
1) describing how to implement the testing program in an appropriate manner,
and 2) providing legal documentation in the case of a legal challenge to
the use of the testing process.
Predictive
Validity Process
The Predictive validity process is
very similar to the concurrent validity process. The difference is that
the validation study is carried out over time. Job applicants are administered
the tests, but the test results are not used in selecting employees. At
a later point in time, say a year after the hiring of the job applicants,
job performance measures are gathered.
Test
scores are used to predict job performance scores. This process most directly
matches the actual hiring process, where test scores at the time of hire
are used to predict future job performance. Consequently, this method provides
the most accurate assessment of test validity. However, it is the most
difficult to implement because of the challenges in gathering the data
over time and assuring that the test scores do not inadvertently influence
the job performance scores.
The process for demonstrating content
validity involves the following steps:
-
Job Analysis. As in content validity,
an analysis of job content is performed.
-
Identification of job-related tests.
The job content information is matched to tests. This process is the same
as the process used in concurrent validity.
-
Validation Study. A set of job
applicants are administered the tests. The test results are not used in
selecting employees; individuals with the full range of high and low scores
are hired. After a period of time, such as one year, the individuals are
assessed in terms of job performance. Test scores are then correlated with
job performance scores.
-
Validation Report. A final report
is prepared. This report has the same content and format as the report
for concurrent validity.
Legal
Issues in Test Validation
The Federal Government, in Title VII
of the Civil Rights Act of 1964, as amended, forbids discrimination on
the basis of race, color, religion, gender, or national origin. The act
prohibits any conditions from being put on employment unless they are a
business necessity. Conditions of business necessity are referred to as
bona fide occupational qualifications (BFOQ).
The
EEOC and three other Federal Government agencies published the Uniform
Guidelines on Employee Selection Procedures
in 1978. This document
defines the nature of discriminatory practices in HR management and provides
a set of guidelines for demonstrating the validity of selection procedures.
In subsequent legal cases, the courts have used the Uniform Guidelines
as the standard against which validity evidence is determined to be legally
defensible. Consequently, it is important to assure that validation procedures
meet the standards identified in the
Uniform Guidelines.
Content validity is addressed in the
Uniform
Guidelines. They state:
"To
demonstrate the content validity of a selection procedure, a user should
show that the behavior(s) demonstrated in the selection procedure are a
representative sample of the behaviors(s) of the job in question or that
the selection procedure provides a representative sample of the work product
of the job." (Section 14C(4)).
To assure legal defensibility, organizations
should:
-
Perform a careful job analysis.
-
Document the validity of the selection
procedure.
-
Implement the selection procedure in a
fair and consistent manner.
By implementing these steps, organizations
may achieve the full benefits of test validation which were listed above.
Page & Associates
2021 Pine Island Road, Minnetonka,
MN 55305
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