1. Chapter 10: Measurement Slavin Reliability & Validity Types of Measures Behavioral Observation Systems Sample Size Determination

2. What is Reliability? Reliability- the degree to which a measure is consistent in producing the same reading or results http://www.wadsworth.com/psychology_d/special _features/ext/workshops/reliability2.html http://www.wadsworth.com/psychology_d/special _features/ext/workshops/reliability2.html

3. What is Validity? Validity- the degree to which something measures the concept it is supposed to measure Common error in educational research is to use standardized achievement tests as an assessment of school learning without examining it carefully to see that it corresponds to what is taught in school

4. Types of Measures: Achievement & Aptitude Tests Aptitude Tests Achievement Tests Standardized Tests Norm-referenced Tests Criterion-referenced tests Authentic Tests Questionnaire Scales

5. Types of Measures: Behavioral Observation Guidelines Define – High-inference behaviors – Low-inference behaviors Schedule Observe Frequency Reliability and bias

6. Sample Size: How many is enough? Sample Size-depends on how variable the data are and how large we expect the effect to be Statistical Power- the ability of a research design to detect true differences and avoid false negative errors