1. NWEA RIT Scale Norms
Some Things You Should Know About the 2011 RIT Scale Norms
Prepared by:
Dan Henderson, NWEA Partner Relations Region Manager
John Woodin, NWEA Partner Relations State Representative

2. Introduction
“No, your students’ performance didn’t change from last spring.”
The norm group and methodology did change
Simply creates a different comparison
A 215 RIT is still a 215 RIT – means the same thing related to performance

3. Key Differences from 2008
Methodology: set of norms more representative of school age population
Everyone will see some changes: status and growth norms
Norms have been applied to both past and current scores (for consistency and growth projections)

4. What will be “fixed” in the 2011 Norms…
Asterisks * will be replaced with 1 or 99 (percentiles)
Kindergarten growth norms will be reinstated for fall to spring
Kindergarten status norms will be reinstated for fall and winter
11th grade norms will be reinstated as soon as possible

5. Partner Accounts Back to Basics 2011
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Sampling student test records
“Students” were randomly sampled from a pool of test event records. (all test records of the student from the study period in the subject of interest)
Pool represented about 5.1 million students,
from 13,000 schools
located in more than 2,700 school districts
from over 50 states and
contained about 35 million test events.
Smallest grade level sample was about 20,000 students.

6. Partner Accounts Back to Basics 2011
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Post-stratification procedures
Based on school-level variables commonly associated with challenges and opportunities
School–level variables: Mix of student ethnicity, percent free/reduced lunch eligibility, Title 1 eligibility, ALL Title 1, grade range served, charter status, magnet status, enrollment at each grade, total enrollment, school level, school type, school locale, pupil-teacher ratio.
Combined to form a School Challenge Index (SCI) for each state – using ALL schools in the state, not only NWEA schools
SCI was used as a post-stratification weight for all analyses

7. Differences in Status Norms
Minor changes in status norms
Percentiles changed very little
Larger changes for grades 1 & 2 for high and low achieving students
Difference in partner base (more schools and students than 2008)
Different methodology for selection which results in more representative norms

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15. Difference in Growth Norms
Less difference in the middle of achievement continuum
Larger differences at the two ends of achievement (especially extremes)
High or low achievers may see larger differences in growth projections
Low Achievers: lower grow projections than in the past
High Achievers: higher growth projections

16. Growth in 2008 Norm study Pt. A Pt. B FALL
Spring
Growth within the grade only

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How growth is conceptualized
Previous grade
Grade of Interest
Next grade S
F W S F 1 36 54 82 72
Instructional weeks 1 2 3 4 5 6
students .
All scores included

18. Flat Growth Rates
Growth projections tend to be flatter in than the 2008 norms
Grades 5, 6, 8 show flat growth in Math
In a large national sample, students in these grades tended to show similar growth regardless of where they were on the RIT scale
Due to sampling methods – overly large impact of extreme scores in 2008

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24. Applying Growth to Past Terms
Since NWEA uses growth norms that overlap from year to year – had to apply the norms backward
Cannot compare 2008 growth norms to growth norms – not comparable