Validity

Main Criteria of Assessment Validity Reliability

What is validity? the extent to which an assessment accurately measures what it is intended to measure. Let me explain this concept through a real-world example. If you weigh yourself on a scale, the scale should give you an accurate measurement of your weight. If the scale tells you you weigh 150 pounds and you actually weigh 135 pounds, then the scale is not valid. the same can be said for assessments used in the classroom. If an assessment intends to measure achievement and ability in a particular subject area but then measures concepts that are completely unrelated, the assessment is not valid.

What is validity? Adequacy and appropriateness of the interpretation and uses of assessment results Is a test actually measuring what it sets out to measure? A matter of degree (high-moderate-low) Specific to some particular use or interpretation, NOT for all purpose or sample Unitary concept (agreed by a group as standard)

Types of Validity Content validity Construct validity Criterion validity Consequential validy (NOPE. DON’T READ THIS!!!!)

Content Validity refers to the extent to which an assessment represents all facets of tasks within the domain being assessed. Content validity answers the question: Does the assessment cover a representative sample of the content that should be assessed? For example, if you gave your students an end-of-the-year cumulative exam but the test only covered material presented in the last three weeks of class, the exam would have low content validity. The entire semester worth of material would not be represented on the exam.

How to Improve Content Validity Content validity is increased when assessments require students to make use of as much of their classroom learning as possible. Increase number of questions Cover all topics (use TOS)

Construct Validity Construct validity refers to whether/how well an assessment, or topics within an assessment, measure the educational/psychological constructs that the assessment was designed to measure. For example, if the construct to be measured is “sales knowledge and skills,” then the assessment designed to measure this construct should show evidence of actually measuring this “sales knowledge and skills” construct.

How to Improve Construct Validity Identify the critical knowledge taught/needed by students Identify the critical skills taught/needed by students Ask questions related to these by using TOS

Criterion Validity

Factors Influencing Validity See page 97-99