U4D1 Discussion Post min. 400 words

two approaches or models of validity—trinitarian and unitary. In some ways, these two models are competing views of gathering evidence for a test's validity. In other ways, the two approaches have an overlap of elements.

For this discussion:

• Compare and contrast these two models in terms of how they conceptualize validity.
• Identify at least one advantage and disadvantage of each model.
• Decide which model appears to be the most valid for determining validity of a test.
• Explain your decision in terms of the implications for decision making about a test's validity.

Be sure to include citations from Guion's 1980 article, "On Trinitarian Doctrines of Validity," and Messick's 1995 article, "Validity of Psychological Assessment: Validation of Inferences From Persons' Responses and Performances As Scientific Inquiry Into Score Meaning."