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ENSURING STATISTICAL LITERACY FOR PRESERVICE EDUCATION MAJORS Stacy M. Bjorkman, Ph.D., NCSP Walden University & Kelly H. Summers Northern Illinois University WHY IS THIS IMPORTANT? In almost every state there has been a shift in the way teachers are evaluated. Most states are including student achievement data as part of the teacher evaluation process. Teachers’ livelihoods depend on knowing about assessments. Most education degree programs do not include coursework in statistics. ENSURING STATISTICAL LITERACY Determine the role of assessments in the teacher evaluation process in your state. Build a pre-service workshop that discusses the role of assessments in teacher evaluations. Design the workshop so the focus is on statistical concepts with real-world educational data. Include key components of assessment and statistical literacy in the workshop. Be sure to include frequent checks for understanding. POSSIBLE CONCEPTS TO INCLUDE IN A PRE-SERVICE WORKSHOP Summative vs. Formative Assessments The concept of reliability The concept of validity Measures of central tendency and variability Reading various types of graphs Types of test scores KEY DIFFERENCES IN FORMATIVE & SUMMATIVE ASSESSMENTS Summative Formative Reasons for Assessing Document individual or group achievement or mastery of standards; measure achievement status at a point in time for purposes of reporting Increase achievement; to help students meet more standards; support ongoing student growth To Inform Others about students Students about themselves Focus of Assessment Achievement standards for which schools, teachers, and students are held accountable Specific achievement targets selected by teachers that enable students to build toward standards Driving Force Accountability Improvement Place in time Event after learning is supposed to have happened Process during learning Chapius, J. & Chapius, C. (2002). Understanding school assessment: A parent and community guide to helping students learn. Assessment Training Institute: Portland, OR. THE CONCEPT OF RELIABILITY What do we mean by reliable? The consistency of a measurement tool Not good or bad, just consistent Want to minimize “measurement error” Test-taker variables Test administration Hot, cold, noise, lack of sleep, lack of food, etc. Lack of standardization either knowingly or unwittingly Test scoring and interpretation Is the test more subjective? Then there will likely be more measurement error. TYPES OF RELIABILITY TO CONSIDER Inter-rater reliability: consistency between scorers Test-retest reliability: variability over time for one person’s score Internal consistency: How well the items on a test measure the same construct WHAT EXACTLY IS VALIDITY? What do we mean by a valid measure? A judgment or estimate of how well a test measures what it purports to measure in a particular context Reliability is solely a statistical measure Validity is determined statistically as well as through common sense judgments CENTRAL TENDENCY Mean, Median, Mode Range Standard deviation Consider the impact of… Small sample sizes Range restriction & outliers High & low achieving students WHAT’S IN A SCORE? Raw scores Standard score A raw score that has been converted from one scale to another scale Percentiles How many items a test taker got correct Divides performance into 100 equal parts Percentage correct THANK YOU! PLEASE CONTACT US WITH QUESTIONS [email protected] & [email protected]