Lessons from Using NWEA’s Vertical Scales Phil Dommes North Thurston Public Schools June 2, 2006

North Thurston Public Schools 1995 – 2005 Customized reading and math tests Fall to Fall

Characteristics of NWEA Tests Common item pool of pre-tested items Common, cross-grade measurement scales for all items in a content area Common test design Common psychometric properties

NWEA Vertical Scales Grade level independent Equal interval

Put Growth into Perspective

Monitoring Growth in Student Achievement Reading Achievement and Growth Fall Spring Mean Growth GradeMedianMeanMedianMean Ending Grade Fall to Spring Fall to Fall Spring to Spring n/a

RIT Block Growth Norms

Learning continuum sequence of skills RIT  Skill  < Whole Numbers -Identify fact families with sums 0-18 in horizontal format - Subtract two numbers in vertical format. -Subtract a 1-digit number from a 2-digit number with no regrouping -- Solve simple addition word problems. -Solve 1- step word problems involving division -Divide a 3- digit or 4- digit number by a 1-digit number. -Understand the concept of division using pictorial representation - Divide a 2- digit by a 2-digit number with a remainder -Divide multi- digit numbers using a calculator N/A Fractions -N/A -Read, shade & write fractional parts of a group -Add mixed numbers with like denominators with regrouping -Multiply mixed numbers Divide a mixed number by a whole number or a fraction Divide a fraction, whole number, or mixed number by a mixed number Multiply a whole number by a fraction Percents -N/A -Write a decimal or fraction as a percent Find the percent one number is of another N/A

Don’t Forget about Error of Measurement

Test # 1 (Obtained Score) Test # 2 (Obtained Score) Most likely: Student’s true score grew 8 points. Plausible: Score increased by 2 points Or Score increased by 16 points.

Be cautious when interpreting subtest results

Test # 1 (Obtained Score) Test # 2 (Obtained Score) Most likely: Student’s true score grew 8 points. Plausible: Student decreased by 4 points Or Student increased by 20 points.

Triangulate the Data

Local Assessment Teacher NWEA TRIANGULATION

When 3 points of data tell the same story about a student, we can comfortably make the appropriate decisions.

Data begins a discussion; it doesn’t end the discussion.