Validity refers to the way in which the results are interpreted and used, but not to the assessment procedure itself (Nitko, 1996, p. 36). Messick (1989) uses four principles for validation of student assessments:

1. the interpretations you give to your students' assessment results are valid only to the degree that you can point to evidence that supports their appropriateness and correctness
2. the uses you make of your assessment results are valid only to the degree to which you can point to evidence that supports their correctness and appropriateness
3. the interpretations and uses of your assessment results are valid only when the values implied by them are appropriate
4. the interpretations and uses you make of your assessment results are valid only when the consequences of these interpretations and uses are consistent with appropriate values

In other words, judgment of the validity depends on knowing the particular interpretation, uses, values, and consequences of the assessment. It relates to the confidence the teacher has in interpreting students' assessment results and how the teacher uses those results.

In a classroom setting, Nitko (p. 39) offers the following criteria for judging the validity of classroom assessment used in the process of assigning grades to students:
 

Nitko, A.J. (1996). Educational Assessment of Students. 2nd ed. Englewood, NJ: Merrill.

1. emphasizes what was taught
2. represents the school's stated curricular content
3. represents current thinking about the subject
4. contains content worth learning

1. requires the student to integrate and use several thinking skills
2. representing thinking processes and skills stated in the school's curriculum
3. contains tasks that cannot be completed without using intended thinking skills
4. allows enough time for students to use complex skills and processes

1. yields patterns of results consistent with other assessments in the class
2. contains individual items that aren't too easy or too difficult

1. uses a systematic procedure for every student to assign quality ratings or marks
2. provides each student with several opportunities to demonstrate competence for each learning target assessed

1. contains tasks that are interpreted appropriately by students with different backgrounds
2. accommodates students with disabilities
3. is free of ethnic, racial and gender biases

1. requires a reasonable amount of time for instructor to construct and administer
2. represents appropriate use of the students' class time
3. represents appropriate use of instructors' class time

1. is used in conjunction with other assessment results for important decisions