Packing and Unpacking Sources
of Validity Evidence: History
Repeats Itself Again
Stephen G. Sireci
University of Massachusetts Amherst
Presentation for the conference
“The Concept of Validity: Revisions, New
Directions, & Applications”
October 9, 2008
University of Maryland, College Park
Validity
A concept that has evolved and is
still evolving
The most important consideration in
educational and psychological
testing
Simple, but complex
– Can be misunderstood
– Disagreements regarding what it is,
and what is important
Purposes of this presentation
Provide some historical context on
the concept of validity in testing
Present current, consensus
definitions of validity
Describe the validation framework
implied in the Standards
Discuss limitations of current
framework
Suggest new directions for validity
research and practice
Packing and unpacking: A prelude
Packing
Does the test measure
what it purports to
measure?
A test is valid for
anything with which it
correlates.
Validity is a unitary
concept.
Unpacking
Predictive, status,
content, congruent
validity
Clarity, coherence,
plausibility of
assumptions (validity
argument)
5 sources of validity
evidence
Validity defined
What is validity?
How have psychometricians come
to define it?
What does valid mean?
Truth?
According to Websters, Valid:
1. having legal force; properly executed and
binding under the law.
2. sound; well grounded on principles or
evidence; able to withstand criticism or
rejection.
3. effective, effectual, cogent
4. robust, strong, healthy (rare)
What is validity?
According to Websters:
Validity:
1. the state or quality of being valid;
specifically, (a) strength or force from
being supported by fact; justness;
soundness; (b) legal strength or force.
2. strength or power in general
3. value (rare)
How have psychometricians
defined validity?
Some History
In the beginning
In the beginning
Modern measurement started at the
turn of the 20th century
1905: Binet-Simon scale
– 30-item scale designed to ensure that
no child could be denied instruction in
the Paris school system without formal
examination
• Binet died in 1911 at age 54
Note
College Board was established in
1900
– Began essay testing in 1901
What else was happening around
the turn of the century?
1896: Karl Pearson, Galton
Professor of Eugenics at University
College, published the formula for
the correlation coefficient
Given the predictive purpose of
Binet’s test,
interest in heredity and individual
differences,
and a new statistical formula
relating variables to one another
validity was initially defined in terms
of correlation
Earliest definitions of Validity
“Valid scale” (Thorndike, 1913)
A test is valid for anything with
which it correlates
– Kelley, 1927; Thurstone, 1932;
– Bingham, 1937; Guilford (1946); others
Validity coefficients
– correlations of test scores with grades,
supervisor ratings, etc.
Validation started with group
tests
1917: Army Alpha and Army Beta
– (Yerkes)
– Classification of 1.5 million recruits
Borrowed items and ideas from Otis
Tests
– Otis was one of Terman’s graduate
students
Military Testing
Tests were added or subtracted to
batteries based solely on
correlational evidence (e.g, increase
in R2).
How well does test predict pass/fail
criterion several weeks later?
Jenkins (1946) and others emerged
in response to problems with notion
that validity=correlation
– See also Pressey (1920)
Problems with notion that
validity = correlation
Finding criterion data
Establishing reliability of criterion
Establishing validity of criterion
If valid, measurable, criteria exist,
why do we need the test?
What did critics of correlational evidence
of validity suggest for validating tests?
Professional judgment
“...it is proper for the test developer to
use his individual judgment in this
matter though he should hardly
accept it as being on par with, or as
worthy of credence as,
experimentally established facts
showing validity.”
– (Kelley, 1927, pp. 30-31)
What did critics of correlational evidence
of validity suggest for validating tests?
Appraisal of test content with
respect to the purpose of testing
(Rulon, 1946)
– rational relationship
Sound familiar?
Early notions of content validity
– (Kelley, Mosier, Rulon, Thorndike,
others)
– but notice Kelley’s hesitation in
endorsing this evidence, or going
against the popular notion
Other precursors to content
validity
Guilford (1946): validity by
inspection?
Gulliksen (1950): “Intrinsic Validity”
– pre/post instruction test score change
– consensus of expert judgment
regarding test content
– examine relationship of test to other
tests measuring same objectives
Herring (1918): 6 experts evaluated the
“fitness of items”
Development of Validity Theory
By the 1950s, there was consensus
that correlational evidence was not
enough
and that judgmental data of the
adequacy of test content should be
gathered
Growing idea of multiple lines of
“validity evidence”
Emergence of Professional
Standards
Cureton (1951): First “Validity”
chapter in first edition of
“Educational Measurement” (edited
by Lindquist).
Two aspects of validity
– Relevance (what we would call
criterion-related)
– Reliability
Cureton (1951)
Validity defined as “the correlation
between actual test scores and true
criterion scores”
but: “curricular relevance or
content validity” may be appropriate
in some situations.
Emergence of Professional
Standards
1952: APA Committee on Test
Standards
– Technical Recommendations for
Psychological Tests and Diagnostic
Techniques: A Preliminary Proposal
Four “categories of validity”
– predictive, status, content, congruent
Emergence of Professional
Standards
1954: APA, AERA, & NCMUE
produced
– Technical Recommendations for
Psychological Tests and Diagnostic
Techniques
Four “types” or “attributes” of
validity:
– construct validity (instead of congruent)
– concurrent validity (instead of status)
– predictive
– content
1954 Standards
Chair was Cronbach and guess who
else was on the Committee?
– Hint: A philosopher
Promoted idea of:
– different types of validity
– multiple types of evidence preferred
– some types preferable in some
situations
Subsequent Developments
1955: Cronbach and Meehl
– Formally defined and elaborated the
concept of construct validity.
– Introduced term “criterion-related
validity”
1956: Lennon
– Formally defined and elaborated the
concept of content validity.
Subsequent Developments
Loevinger (1957): big promoter of
construct validity idea.
Ebel (1961…): big antagonist of
unified validity theory
– Preferred “meaningfulness”
Evolution of Professional
Standards
1966: AERA, APA, NCME
Standards for Educational and
Psychological Tests and Manuals
Three “aspects” of validity:
– Criterion-related (concurrent +
predictive)
– Construct
– Content
1966: Standards
Introduced notion that test users are
also responsible for test validity
Specific testing purposes called for
specific types of validity evidence.
– Three “aims of testing”
• present performance
• future performance
• standing on trait of interest
Important developments in content
validation
Evolution of Professional
Standards
1974: AERA, APA, NCME
Standards for Educational and
Psychological Tests
Validity descriptions borrowed
heavily from Cronbach (1971)
– Validity chapter in 2nd edition of
“Educational Measurement” (edited by
R.L. Thorndike)
1974: Standards
Defined content validity in
operational, rather than theoretical,
terms.
Beginning of notion that construct
validity is much cooler than content
or criterion-related.
Early consensus of “unitary”
conceptualization of validity
Evolution of Professional
Standards
1985: AERA, APA, NCME
Standards for Educational and
Psychological Testing
note “ing”
Described validity as unitary
concept
Notion of validating score-based
inferences
Very Messick-influenced
1985 Standards
More responsibility on test users
More standards on applications and
equity issues
Separate chapters for
– Validity
– Reliability
– Test development
– Scaling, norming, equating
– Technical manuals
1985 Standards
New chapters on specific testing
situations
– Clinical
– Educational
– Counseling
– Employment
– Licensure & Certification
– Program Evaluation
– Linguistic Minorities
– “People who have handicapping
conditions”
1985 Standards
New chapters on
– Administration, scoring, reporting
– Protecting the rights of test takers
– General principles of test use
Listed standards as
– primary,
– secondary, or
– conditional.
1999 Standards
 New “Fairness in Testing” section
 No more “primary,” “secondary,”
“conditional.”
 3-part organizational structure
1. Test construction, evaluation, &
documentation
2. Fairness in testing
3. Testing applications
1999 Standards (2)
 Incorporated the “argument-based
approach to validity”
Five “Sources of Validity Evidence”
1. Test content
2. Response processes
3. Internal structure
4. Relations to other variables
5. Testing consequences
We’ll return to these sources later.
Comparing the Standards: Packing
& Unpacking Validity Evidence
Edition
Validity
1954
Construct, concurrent, predictive,
content
Criterion-related, construct,
content
Criterion-related, construct,
content
Unitary (but, content-related
evidence, etc.)
Unitary: 5 sources of evidence
1966
1974
1985
1999
What are the current and
influential definitions of validity?
Cronbach: Influential, but not
current (1971…)
Messick (1989…)
Shepard (1993)
Standards (1999)
Kane (1992, 2006)
Messick (1989): 1st sentence
“Validity is an integrated evaluative
judgment of the degree to which
empirical evidence and theoretical
rationales support the adequacy
and appropriateness of inferences
and actions based on test scores
and other modes of assessment.”
(p. 13)
This “integrated” judgment led
Messick, and others, to conclude
All validity is construct validity.
It outside my purpose today to debate
the unitary conceptualization of
validity, but like all theories, it has
strengths and limitations.
But two quick points…
Unitary conceptualization of
validity
Focuses on inferences derived from
test scores
– Assumes measurement of a construct
motivates test development and
purpose
The focus on analysis of scores
may undermine attention to content
validity
Removal of term “content validity”
may have had negative effect on
validation practices.
Consider Ebel (1956)
“The degree of construct validity of a
test is the extent to which a system
of hypothetical relationships can be
verified on the basis of measures of
the construct…but this system of
relationships always involves
measures of observed behaviors
which must be defended on the
basis of their content validity” (p.
274).
Consider Ebel (1956)
“Statistical validation is not ann
alternative to subjective evaluation,
but an extension of it. All statistical
procedures for validating tests are
based ultimately upon common
sense agreement concerning what
is being measured by a particular
measurement process” (p. 274).
The 1999 Standards accepted
the unitary conceptualization,
but also took a practical stance.
The practical stance stems from the
use of an argument-based approach
to validity.
– Cronbach (1971, 1988)
– Kane (1992, 2006)
The Standards (1999)
succinctly defined validity
“Validity refers to the degree to which
evidence and theory support the
interpretations of test scores entailed
by proposed uses of tests.” (p. 9)
Why do I say the Standards
incorporated the argument-based
approach to validation?
“Validation can be viewed as
developing a scientifically sound
validity argument to support the
intended interpretation of test
scores and their relevance to the
proposed use.”
(AERA et al., 1999, p. 9)
Kane (1992)
“it is not possible to verify the
interpretive argument in any
absolute sense. The best that
can be done is to show that the
interpretive argument is highly
plausible, given all available
evidence” (p. 527).
Kane: Argument-based approach
a) Decide on the statements and
decisions to be based on the test
scores.
b) Specify inferences/assumptions
leading from test scores to
statements and decisions.
c) Identify competing interpretations.
d) Seek evidence supporting
inferences and assumptions and
refuting counterarguments.
Philosophy of Validity
Messick (1989)
“if construct validity is considered to
be dependent on a singular
philosophical base such as logical
positivism and that basis is seen to
be deficient or faulty, then construct
validity might be dismissed out of
hand as being fundamentally
flawed” (p. 22).
Messick (1989)
“nomological networks are viewed as
an illuminating way of speaking
systematically about the role of
constructs in psychological theory
and measurement, but not as the
only way” (p. 23).
3 perspectives on rel. b/w test
and other indicators of construct
1. Test and nontest consistencies are
manifestations of real traits.
2. Test and nontest consistencies are
defined by rel. among constructs
in a theoretical framework.
3. Test and nontest consistencies are
attributable to real entities but are
understood in terms of constructs.
See Messick (1989) Figures 2.1-2.3
Messick on test validation
“test validation is a process of
inquiry” (p. 31)
5 systems of inquiry
– Leibnizian
– Lockean
– Kantian
– Hegelian
– Singerian
Systems of inquiry
Main points
– Validation can seek to confirm
– Validation can seek consensus
(Leibniz, Lock)
– Validation can seek alternative
hypotheses
– Validation can seek to disconfirm
(Kant, Hegel, Singer)
Two other important points by
Messick (1989)
“the major limitation is shortsightedness
with respect to other possibilities” (p. 33)
“The very variety of methodological
approaches in the validational
armamentarium, in the absence of
specific criteria for choosing among
them, makes it possible to select
evidence opportunistically and to ignore
negative findings” (p. 33)
If you look at the seminal papers
and textbooks, and the various
editions of the Standards, there
are several fundamental and
consensus tenets about validity
theory and test validation.
Fundamental Validity Tenets
Validity is NOT a property of a test.
A test cannot be valid or invalid.
What we seek to validate are
(inferences) uses of test scores.
Validity is not all or none.
Test validity must be evaluated with
respect to a specific testing purpose.
Thus, a test may be appropriate for
one purpose, but not for another.
Fundamental Validity Tenets
(cont.)
Evaluating the validity of inferences
derived from test scores requires
multiple lines of evidence (i.e., different
types of evidence for validity).
Test validation never ends—it is an
ongoing process.
I believe these tenets can be
considered “consensus” due to
their incorporation in the
standards and predominance in
the literature.
But of course, not everyone need
agree with consensus, and we will
here important points from
detractors over the next two days.
Criticisms of this perspective
Tests are never truly validated (we
are never done).
No prescription or guidance
regarding specific types of evidence
to gather and how to gather it.
Ideal goals with no guidance leads
to inaction.
The argument-based approach is
a compromise between
sophisticated validity theory and
the reality that at some point, we
must make a judgment about the
defensibility and suitability of
use of a test for a particular
purpose.
What guidance does the
Standards give us?
 Five “sources of evidence that
might be used in evaluating a
proposed interpretation of test
scores for particular purposes”
(Messick, 1989, p. 13).
“Validation is a matter of making the
most reasonable case to guide both
current use of the test and current
research to advance understanding
of what the test scores mean…
To validate an interpretive inference is
to ascertain the degree to which
multiple lines of evidence are
consonant with the inference, while
establishing that alternative
inferences are less well supported.”
The current Standards
Provide a useful framework for
evaluating the use of a test for a
particular purpose.
– And for documenting validity evidence
Allow us to use multiple lines of
evidence to support use of a test for
a particular purpose
But, are not prescriptive and do not
provide examples or references to
“adequate” validity arguments.
Standards’ Validation
Framework
Validity evidence based on
1. Test content
2. Response processes
3. Internal structure
4. Relations to other variables
5. Testing consequences
What is helpful in the Standards
framework?
It provides a system for categorizing
validity evidence so that a coherent
set of evidence can be put forward.
It provides a way of standardizing
the reporting of validity evidence.
It focuses on both test construction
and test score validation activities.
Emphasizes the importance of
evaluating consequences
What are the limitations in the
Standards framework?
Not all types of evidence of validity
fit into the 5 sources categories.
No examples of good validation
studies or of when sufficient
evidence is put forth
No statistical guidance
No references
Vagueness in some areas
Suggestions for revising the
Standards (1)
Need to refine sources of validity
evidence to accommodate
– Analysis of group differences
– Alignment research
– Differential item functioning
– Statistical analysis of test bias
Need more clarity on validity
evidence for accountability testing
(groups, rather than individuals)
Suggestions for revising the
Standards (2)
Need to define “score
comparability”
– Across subgroups of examinees
taking a single assessment
– Across accommodations to
standardized assessments
– Across different language versions
of an assessment
– Across different tests in CAT/MST
– Across different modes of
assessment
Suggestions for revising the
Standards (3)
Include specific examples of
laudable test validation
analyses and references to
studies that exemplify sound
validity arguments.
Closing remarks
There are different perspectives on
validity theory.
Whether a test is valid for a
particular purpose will always be a
question of judgment.
A sound validity argument makes
the judgment an easy one to make.
Closing remarks (2)
For educational tests, validity
evidence based on test content, is
fundamental. Without confirming
the content tested is consistent with
curricular goals, the test adequately
represents the intended domain,
and the test is free of constructirrelevant material, the utility of the
test for making educational
decisions will be undermined.
Why are there different
perspectives on validity?
It’s philosophy.
It’s okay to disagree, but we need
consensus with respect to
nomenclature, and that is where
differences can hurt us as a
profession.
For over 50 years, the Standards
have provided consensus
definitions.
Remember, thhreats to validity
boil down to
Construct underrepresentation
Construct-irrelevant variance
“Tests are imperfect measures of
constructs because they either
leave out something that should be
included…or else include
something that should be left out, or
both” (Messick, 1989, p. 34)
Adhering to and Improving the
Standards
I don’t agree with everything in the
Standards.
But I find it easier to work within the
framework, than against it.
Advice for the remainder of the
conference, and for your future
validity endeavors
If you criticize, have specific
improvements to contribute.
– (e.g., evidence-centered design)
Consider different perspectives on
validity when evaluating use of a
test for a particular purpose
– If one statistical analysis is offered as
“validation,” be suspicious
– Look for evidence in test construction
Thank you for your attention
And thanks to Bob Lissitz and UMD
for the invitation and for holding this
conference.
I look forward to continuing the
conversation.
There is certainly a lot more to hear,
and to say.
[email protected]
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