Basic Concepts of Measurement

1. Basic Concepts of Measurement • Focus Questions? • Why should assessment be a central focus of my instructional practice? • How are tests developed? • What are the limitations of these instruments?

2. Terminology • Raw score - the number of items answered correctly. • Mean – Average • Range – The spread of the scores (top# -bottom#) • Standard Deviation – Measure the distance scores depart from the mean (helps us quantify the spread of the distribution)

3. Standardization and Norms • Standardized tests eliminate bias (supposedly). • Principles to follow: • Match the test to the question you want to answer, Use standardized measures according to the designed purpose, choose tests that are valid and reliable,you must follow the directions of standardized tests exactly, be sure to understand what the test reports and the statistics generated, use multiple assessment methods to evaluate children and programs.

4. Standardized/Norm-referenced Test • A task or a set of tasks given under prescribed conditions and designed to assess some aspect of a person’s knowledge, skill, or personality. • In designing a standardized test- rationale, what is to be measured, who will be measured, how the results will be used. • Remember to ascertain that the test was developed to children who are similar to your children (population v sample) • Norming is the process of finding out what score most children of a given age will earn …

5. Different Types of Test Scores • Developmental scores – Grade equivalent scores • Percentile Ranks • Stanines

6. Reliability • Reliability refers to consistency, dependability, or stability. If a test can generalize to different times, it has test-retest reliability. If a test can generalize to other testers, it has interscorer reliability.

7. Validity • Validity refers to the extent to which a test measures what it is supposed to measure what it is supposed to measure.(face validity, content validity etc.