Practical Measurement Concepts in Education

1. What is validity, why is it important in testing, and what is the basic question of validity? If another teacher told you that a particular test had high validity, what questions would you ask to confirm this?

Validity is the best available approximation to the truth or falsity of a given inference, conclusion or decision. It involves the degree to which you are measuring what you are supposed to measure. Simply put to accuracy of your measurement.

In testing, validity gives meaning to test scores. It tells you how good a test is for a particular situation. It refers to what characteristics the test measures and how well the test measures those characteristics.

The basic questions of validity are:

"How well does the instrument measure what it was designed to measure?"

"Does the instrument do what it is supposed to do?"

The questions I would ask to confirm high validity are as follows:

"What are the intended uses of the test?"

"Who is the test designed for?"

"What is the basis for considering whether the test applies to your students?"

"Is it consistent with the worthwhile quality you think you're measuring?"

"Does the test successfully predict future outcomes?"

2. What is reliability, why is it important in testing, and what is the basic question of reliability?

Reliability is the consistency of your measurement, or the degree that an instrument measures the same way each time it is used under the same condition with the same subject.

In testing, reliability tells you how trustworthy a score on that test will be. It refers to how dependably or consistently a test measures a characteristic.

The basic question of reliability is:

"Does the test or scale measure in the same way regardless of who is administering it and how it is administered?"

3. What are national norms and why do we use them to measure student performance” What are classroom norms and under what conditions is it possible for a teacher to develop and use classroom norms?

National Norms are the standard of comparison used in making decisions about a student's performance. National Norms measure the range of test scores that represents the average or usual performance nationwide rather than locally.

Classroom Norms are the behavioral expectations or rules of the class.

Classroom Norms should be developed the first day of school to inform a class how they are expected to behave towards each other, teachers, school property, and towards the materials used in schoolwork.