Editing Construct validity (section)

== History ==
Throughout the 1940s scientists had been trying to come up with ways to validate experiments prior to publishing them. The result of this was a plethora of different validities ([[intrinsic validity]], [[face validity]], [[logical validity]], [[empirical validity]], etc.). This made it difficult to tell which ones were actually the same and which ones were not useful at all. Until the middle of the 1950s, there were very few universally accepted methods to validate psychological experiments. The main reason for this was because no one had figured out exactly which qualities of the experiments should be looked at before publishing. Between 1950 and 1954 the APA Committee on Psychological Tests met and discussed the issues surrounding the validation of psychological experiments.<ref name="Cronbach55"/>

Around this time the term construct validity was first coined by [[Paul Meehl]] and [[Lee Cronbach]] in their seminal article "Construct Validity In Psychological Tests". They noted the idea that construct validity was not new at that point; rather, it was a combination of many different types of validity dealing with theoretical concepts. They proposed the following three steps to evaluate construct validity:
# articulating a set of theoretical concepts and their interrelations
# developing ways to measure the hypothetical constructs proposed by the theory
# empirically testing the hypothesized relations<ref name="Cronbach55"/>

Many psychologists noted that an important role of construct validation in [[psychometrics]] was that it placed more emphasis on theory as opposed to validation. This emphasis was designed to address a core requirement that validation include some demonstration that the test measures the theoretical construct it purported to measure. Construct validity has three aspects or components: the substantive component, structural component, and external component.<ref name= "Loevinger">{{cite journal | author = Loevinger J | year = 1957 | title = Objective Tests As Instruments Of Psychological Theory: Monograph Supplement 9 | journal = Psychological Reports | volume = 3 | issue = 3| pages = 635–694 | doi=10.2466/pr0.1957.3.3.635| s2cid = 145640521 }}</ref> They are closely related to three stages in the test construction process: constitution of the pool of items, analysis and selection of the internal structure of the pool of items, and correlation of test scores with criteria and other variables.

In the 1970s there was growing debate between theorists who began to see construct validity as the dominant model pushing towards a more unified theory of validity, and those who continued to work from multiple validity frameworks.<ref name="Kane06">{{cite journal |last=Kane |first=M. T. |year=2006 |title= Validation. |journal=Educational Measurement |volume=4 |pages=17–64}}</ref>  Many psychologists and education researchers saw "predictive, concurrent, and content validities as essentially ''ad hoc'', construct validity was the whole of validity from a scientific point of view"<ref name="Loevinger"/> In the 1974 version of ''The [[Standards for Educational and Psychological Testing]]'' the inter-relatedness of the three different aspects of validity was recognized: "These aspects of validity can be discussed independently, but only for convenience. They are interrelated operationally and logically; only rarely is one of them alone important in a particular situation".

In 1989 Messick presented a new conceptualization of construct validity as a unified and multi-faceted concept.<ref name="Messick89">{{cite book |last=Messick |first=S. |year=1989 | chapter=Validity. |editor=R. L. Linn|title=Educational Measurement |edition=3rd |pages=13–103 |publisher=New York: American Council on Education/Macmillan}}</ref> Under this framework, all forms of validity are connected to and are dependent on the quality of the construct. He noted that a unified theory was not his own idea, but rather the culmination of debate and discussion within the scientific community over the preceding decades. There are six aspects of construct validity in Messick's unified theory of construct validity:<ref name="Messick95">{{cite journal |last=Messick |first=S. |year=1995 |title=Standards of validity and the validity of standards in performance assessment. |journal=Educational Measurement: Issues and Practice |volume=14 |issue=4 |pages=5–8 |doi=10.1111/j.1745-3992.1995.tb00881.x}}</ref> 
#'''Consequential''' – What are the potential risks if the scores are invalid or inappropriately interpreted? Is the test still worthwhile given the risks?
#'''Content''' – Do test items appear to be measuring the construct of interest?
#'''Substantive''' – Is the theoretical foundation underlying the construct of interest sound?
#'''Structural''' – Do the interrelationships of dimensions measured by the test correlate with the construct of interest and test scores?
#'''External''' – Does the test have convergent, discriminant, and predictive qualities?
#'''Generalizability''' – Does the test generalize across different groups, settings and tasks?

How construct validity should properly be viewed is still a subject of debate for validity theorists. The core of the difference lies in an [[epistemology|epistemological]] difference between [[positivist]] and [[postpositivist]] theorists.