Unified validity is a correlation of the content, consequential andcriterion aspects of validity and it further integrates theirconsiderations into a comprehensive construct validity framework(Messick, 1995). It examines the rational postulates about the scoresignificance and the significant theoretical correlations such asthose of a scientific and applied nature (Messick, 1995). Further,the unified notion of validity is essential in both testinterpretation and use because it focuses on score meaning and alsoon the social values.
The comprehensive theory of unified validity comprises of six uniqueaspects. The elements include content, external, substantive,generalizability, consequential and structural features of theconstruct validity (Messick, 1995). Each aspect of the unifiedvalidity theory is essential since they all provide a way of tacklinguseful facets of validity that aid in separating the complexitiesassociated with evaluating the meaning, significance, andappropriateness of the score implications.
Significance of Unified Validity in Educational Research
In educational research, validity is a critical aspect of theeffectiveness of any study. The worth of the study depends on howvalid it is since invalid research is worthless. Moreover, unifiedvalidity is a fundamental requirement of a qualitative educationalresearch. The six aspects of construct validity are employed ineducational measurement including the assessment of performances. Thesix elements together give a means of tackling the validity questionsthat require answers to justify result interpretation and utilization(Messick, 1995).
The educational research utilizes unified validity in interpretingand making action inferences based on observations or certainconsistent behaviors and attributes that have been documented(Messick, 1995). Invalidity during a qualitative educational researchcan occur due to construct underrepresentation and constructirrelevant variance where the assessment is too narrow or too broadrespectively (Messick, 1995). The six aspects of unified validity aidin omitting the sources of invalidity during an educational research.
Unified validity has a four-fold crosscutting that consists ofevidential basis and a consequential basis. The evidential basisemploys construct validity and relevance in test interpretation anduse. Consequential basis uses construct validity, value implications,social consequences and utility in test interpretation and usage(Messick, 1995). All the facets are critical in educational researchsince they help in making a unified validation of the study. Finally,test interpretation and utilization, meaning and values are allincorporated in the validation process, and a unified theory ofvalidation is critical in making action inferences in during aqualitative educational study.
Unified validity in educational research is also essential in tests.The scores given in a test can be qualitative, and the scoring modelsshould be consistent with the understood structural relations inplace. A valid test should address the six aspects of constructvalidity, and also it must show fitness for purpose. Regarding testvalidation, meaning and value are critical issues since, theappropriateness, significance, and meaningfulness of the score-basedinterpretations are inseparable (Messick, 1995). Unified validationin educational research requires proof associated with all thesefacets integrated into a general validity judgment to uphold thescore inferences and their action interpretations or provide adequatereasons for there being no link (Messick, 1995).
In conclusion, test and score validation in educational researchsince they empirically evaluate the consequences and meaning of ameasurement and unified validity combines rational argument with ascientific inquiry to nullify or justify score analysis and usage.
Messick, S. (1995). The validity of psychological assessment:validation of the inferences from persons` responses and performancesas scientific inquiry into score meaning. American psychologist,50(9), 741.