Ch+5+notes

Chapter 5: Validity and Reliability Brief Summary Chapter 5 will focus on two very important concepts-** Validity ** and ** Reliability **. In order to use any instrument in the assessment process, it is mandated under federal law that the tests be both validated and reliable. What does that mean? How does an evaluator determine which tests are the most valid and reliable. There are many types of validity and reliability that are important to know when doing an assessment in special education. After reading this chapter, your students should understand: 􀂃 The purpose for needing valid and reliable measures 􀂃 The most important and often utilized types of validity seen in special education assessment 􀂃 The most important and often utilized types of reliability seen in special education assessment. Lecture and Discussion Outline I. Validity A. Overview II. Types of Validity A. Criterion Related Validity 1. Validity coefficient B. Concurrent validity 1. Predictive validity 2. Content validity C. Construct Validity 1. Convergent validity 2. Discriminant validity III. Factors Affecting Validity A. Test related factors B. The criterion to which you compare your instrument may not be well enough established C. Intervening events D. Reliability IV. Reliability A. Overview B. Reliability Coefficients V. Types of Reliability A. Test-Retest Reliability B. Split-half Reliability or Internal Consistency C. Inter-rater reliability 34 1. Target behaviors 2. Formula for inter-rater reliability D. Alternate Forms Reliability 1. Equivalent forms reliability 2. Parallel forms reliability VI. Standard Error of Measurement A. Obtained score B. True score C. Error score VII. Factors Affecting Reliability A. Test Length B. Test-retest interval C. Variability of scores D. Guessing E. Variation within the test situation VIII. Conclusion