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KENTUCKY LINKING STUDY

A Study of the Alignment of the NWEA RIT Scale

with the Kentucky Performance Rating for Educational Progress (K-PREP) Testing Program

August 2015

COPYRIGHT © 2015 NORTHWEST EVALUATION ASSOCIATION

All rights reserved. No part of this document may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from NWEA.

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A STUDY OF THE ALIGNMENT OF THE NWEA RIT SCALE WITH THE KENTUCKY PERFORMANCE RATING FOR EDUCATIONAL PROGRESS (K-PREP) TESTING PROGRAM

AUGUST 2015

Recently, NWEA completed a study to connect the scale of the Kentucky Performance Rating for Educational Progress (K-PREP) Testing Program used for Kentucky’s mathematics and reading assessments with NWEA’s RIT scale. Information from the state assessments was used in a study to establish performance-level scores on the RIT scale that would indicate a good chance of success on these tests.

To perform the analysis, we linked together state test and NWEA test results for a sample of 49,093 Kentucky students who completed both exams in the spring of 2014 or spring of 2013, the term in which the K-PREP is administered. For the spring season, an Equipercentile method was used to estimate the RIT score equivalent to each state performance level. For fall and winter, we determined the percentage of the population within the selected study group that performed at each level on the state test and found the equivalent percentile ranges within the NWEA dataset to estimate the cut scores. For example, if 40% of the study group population in grade 3 mathematics performed below the proficient level on the state test, we would find the RIT score that would be equivalent to the 40th percentile for the study population (this would not be the same as the 40th percentile in the NWEA norms). This RIT score would be the estimated point on the NWEA RIT scale that would be equivalent to the minimum score for proficiency on the state test. Documentation about this method can be found on our website.

Table Sets 1 and 2 show the best estimate of the minimum RIT equivalent to each state performance level for current-season (spring) and prior-season (fall / winter)1 RIT scores. These tables can be used to identify students who may need additional help to perform well on these tests.

Table Sets 3 and 4 show the estimated probability of a student receiving a proficient score on the state assessment, based on that student’s RIT score. These tables can be used to assist in identifying students who are not likely to pass these assessments, thereby increasing the probability that intervention strategies will be planned and implemented. These tables can also be useful for identifying target RIT-score objectives likely to correspond to successful or “proficient” performance on the state test.

This study has been updated to reflect the 2015 NWEA Norms values. For spring estimates, only the percentile values associated with the cut scores have changed. For the interpolated fall/winter estimates, cut scores and probabilities have been adjusted to reflect the updated normative values.

Table 5 shows the correlation coefficients between MAP and the state test in each grade. These statistics show the degree to which MAP and the state test are linearly related, with values at or near 1.0 suggesting a perfect linear relationship, and values near 0.0 indicating no linear relationship. Table 6 shows the percentages of students at each grade and within each subject whose status on the state test.

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TABLE SET 1 – MINIMUM ESTIMATED CURRENT SEASON (SPRING) RIT CUT SCORES CORRESPONDING TO STATE PERFORMANCE LEVELS

MATH - Spring (Current) Season Cut Scores and %tiles for each State Performance Level

Grade Novice Apprentice Proficient Distinguished

Cut

Score Cut

Score %tile Cut

Score %tile Cut

Score %tile 2 <183 183 25 194 55 206 84 3 <194 194 25 205 55 217 84 4 <201 201 20 213 49 225 78 5 <205 205 16 221 49 236 82 6 <207 207 14 225 49 238 78 7 <213 213 19 231 55 246 84 8 <217 217 23 235 58 253 88

READING - Spring (Current) Season Cut Scores and %tiles for each State Performance Level

Grade Novice Apprentice Proficient Distinguished

Cut

Score Cut

Score %tile Cut

Score %tile Cut

Score %tile 2 <181 181 31 191 56 200 77 3 <191 191 31 201 56 210 77 4 <198 198 30 208 56 220 83 5 <204 204 30 213 53 226 83 6 <208 208 30 217 53 229 82 7 <209 209 27 219 52 232 82 8 <214 214 35 224 60 237 86

*Note: the cut scores shown in this table are the minimum estimated scores. Meeting the minimum MAP cut score corresponds to a 50% probability of achieving that performance level. Use the probabilities in Table Set 3 to determine the appropriate ‘target’ scores for a desired level of certainty. Italics represent extrapolated data.

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TABLE SET 2 – MINIMUM ESTIMATED PRIOR SEASON (FALL / WINTER) RIT CUT SCORES CORRESPONDING TO STATE PERFORMANCE LEVELS

MATH - Fall (Prior) Season Cut Scores and %tiles for each State Performance Level

Grade Novice Apprentice Proficient Distinguished

Cut

Score Cut

Score %tile Cut

Score %tile Cut

Score %tile 2 <168 168 25 179 56 190 84 3 <182 182 26 192 55 203 83 4 <190 190 19 202 50 213 79 5 <197 197 16 211 49 225 82 6 <201 201 14 217 48 230 79 7 <208 208 19 225 56 239 84 8 <213 213 23 230 58 247 88

READING - Fall (Prior) Season Cut Scores and %tiles for each State Performance Level

Grade Novice Apprentice Proficient Distinguished

Cut

Score Cut

Score %tile Cut

Score %tile Cut

Score %tile 2 <167 167 31 177 56 186 77 3 <180 180 30 191 57 200 77 4 <190 190 30 201 57 213 83 5 <198 198 31 207 53 220 83 6 <203 203 30 212 53 225 83 7 <205 205 27 215 51 228 81 8 <211 211 35 221 59 234 86

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MATH - Winter (Prior) Season Cut Scores and %tiles for each State Performance Level

Grade Novice Apprentice Proficient Distinguished

Cut

Score Cut

Score %tile Cut

Score %tile Cut

Score %tile 2 <178 178 26 188 55 199 83 3 <189 189 24 200 55 211 83 4 <197 197 21 208 48 220 79 5 <202 202 16 217 49 231 82 6 <205 205 14 222 50 234 77 7 <211 211 19 228 54 243 84 8 <216 216 24 233 58 251 88

READING - Winter (Prior) Season Cut Scores and %tiles for each State Performance Level

Grade Novice Apprentice Proficient Distinguished

Cut

Score Cut

Score %tile Cut

Score %tile Cut

Score %tile 2 <177 177 32 186 55 195 77 3 <188 188 31 198 56 207 77 4 <196 196 31 206 56 218 83 5 <202 202 30 211 53 224 83 6 <207 207 31 215 52 228 83 7 <208 208 28 218 53 231 83 8 <213 213 35 223 60 236 86

*Note: the cut scores shown in this table are the minimum estimated scores. Meeting the minimum MAP cut score corresponds to a 50% probability of achieving that performance level. Use the probabilities in Table Set 4 to determine the appropriate ‘target’ scores for a desired level of certainty. Italics represent extrapolated data.

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TABLE SET 3 –ESTIMATED PROBABILITY OF SCORING AS PROFICIENT OR HIGHER ON THE STATE TEST IN THE CURRENT SEASON (SPRING), BY STUDENT GRADE AND RIT SCORE RANGE ON MAP ASSESSMENT

MATH - Spring (Current) Season

Estimated Probability of Passing State Test Based on Observed MAP Score

RIT Range 2 3 4 5 6 7 8

120 0% 0% 0% 0% 0% 0% 0%

125 0% 0% 0% 0% 0% 0% 0%

130 0% 0% 0% 0% 0% 0% 0%

135 0% 0% 0% 0% 0% 0% 0%

140 0% 0% 0% 0% 0% 0% 0%

145 1% 0% 0% 0% 0% 0% 0%

150 1% 0% 0% 0% 0% 0% 0%

155 2% 1% 0% 0% 0% 0% 0%

160 4% 1% 0% 0% 0% 0% 0%

165 6% 2% 1% 0% 0% 0% 0%

170 9% 3% 1% 1% 0% 0% 0%

175 14% 5% 2% 1% 1% 0% 0%

180 21% 8% 4% 2% 1% 1% 0%

185 31% 12% 6% 3% 2% 1% 1%

190 43% 18% 9% 4% 3% 2% 1%

195 55% 27% 14% 7% 5% 3% 2%

200 67% 38% 21% 11% 8% 4% 3%

205 77% 50% 31% 17% 12% 7% 5%

210 85% 62% 43% 25% 18% 11% 8%

215 90% 73% 55% 35% 27% 17% 12%

220 94% 82% 67% 48% 38% 25% 18%

225 96% 88% 77% 60% 50% 35% 27%

230 98% 92% 85% 71% 62% 48% 38%

235 99% 95% 90% 80% 73% 60% 50%

240 99% 97% 94% 87% 82% 71% 62%

245 99% 98% 96% 92% 88% 80% 73%

250 100% 99% 98% 95% 92% 87% 82%

255 100% 99% 99% 97% 95% 92% 88%

260 100% 100% 99% 98% 97% 95% 92%

265 100% 100% 99% 99% 98% 97% 95%

270 100% 100% 100% 99% 99% 98% 97%

275 100% 100% 100% 100% 99% 99% 98%

280 100% 100% 100% 100% 100% 99% 99%

285 100% 100% 100% 100% 100% 100% 99%

290 100% 100% 100% 100% 100% 100% 100%

295 100% 100% 100% 100% 100% 100% 100%

300 100% 100% 100% 100% 100% 100% 100%

*Note: This table provides the estimated probability of passing the state test based on a MAP test score taken during the current (spring) season. Example: if a fifth grade student scored 200 on a MAP test taken during the spring season, her/his estimated probability of passing the state test is 11%.

Italics represent extrapolated

data.

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READING - Spring (Current) Season

Estimated Probability of Passing State Test Based on Observed MAP Score

RIT Range 2 3 4 5 6 7 8

120 0% 0% 0% 0% 0% 0% 0%

125 0% 0% 0% 0% 0% 0% 0%

130 0% 0% 0% 0% 0% 0% 0%

135 0% 0% 0% 0% 0% 0% 0%

140 1% 0% 0% 0% 0% 0% 0%

145 1% 0% 0% 0% 0% 0% 0%

150 2% 1% 0% 0% 0% 0% 0%

155 3% 1% 0% 0% 0% 0% 0%

160 4% 2% 1% 0% 0% 0% 0%

165 7% 3% 1% 1% 1% 0% 0%

170 11% 4% 2% 1% 1% 1% 0%

175 17% 7% 4% 2% 1% 1% 1%

180 25% 11% 6% 4% 2% 2% 1%

185 35% 17% 9% 6% 4% 3% 2%

190 48% 25% 14% 9% 6% 5% 3%

195 60% 35% 21% 14% 10% 8% 5%

200 71% 48% 31% 21% 15% 13% 8%

205 80% 60% 43% 31% 23% 20% 13%

210 87% 71% 55% 43% 33% 29% 20%

215 92% 80% 67% 55% 45% 40% 29%

220 95% 87% 77% 67% 57% 52% 40%

225 97% 92% 85% 77% 69% 65% 52%

230 98% 95% 90% 85% 79% 75% 65%

235 99% 97% 94% 90% 86% 83% 75%

240 99% 98% 96% 94% 91% 89% 83%

245 100% 99% 98% 96% 94% 93% 89%

250 100% 99% 99% 98% 96% 96% 93%

255 100% 100% 99% 99% 98% 97% 96%

260 100% 100% 99% 99% 99% 98% 97%

265 100% 100% 100% 99% 99% 99% 98%

270 100% 100% 100% 100% 100% 99% 99%

275 100% 100% 100% 100% 100% 100% 99%

280 100% 100% 100% 100% 100% 100% 100%

285 100% 100% 100% 100% 100% 100% 100%

290 100% 100% 100% 100% 100% 100% 100%

295 100% 100% 100% 100% 100% 100% 100%

300 100% 100% 100% 100% 100% 100% 100%

*Note: This table provides the estimated probability of passing the state test based on a MAP test score taken during the current (spring) season. Example: if a fifth grade student scored 200 on a MAP test taken during the spring season, her/his estimated probability of passing the state test is 21%.

Italics represent extrapolated

data.

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TABLE SET 4 –ESTIMATED PROBABILITY OF SCORING PROFICIENT OR HIGHER ON THE STATE TEST IN PRIOR SEASONS (FALL / WINTER), BY STUDENT GRADE AND RIT SCORE RANGE ON MAP

MATH - Fall (Prior) Season

Estimated Probability of Passing State Test Based on Observed MAP Score

RIT Range 2 3 4 5 6 7 8

120 0% 0% 0% 0% 0% 0% 0%

125 0% 0% 0% 0% 0% 0% 0%

130 1% 0% 0% 0% 0% 0% 0%

135 1% 0% 0% 0% 0% 0% 0%

140 2% 1% 0% 0% 0% 0% 0%

145 3% 1% 0% 0% 0% 0% 0%

150 5% 1% 1% 0% 0% 0% 0%

155 8% 2% 1% 0% 0% 0% 0%

160 13% 4% 1% 1% 0% 0% 0%

165 20% 6% 2% 1% 1% 0% 0%

170 29% 10% 4% 2% 1% 0% 0%

175 40% 15% 6% 3% 1% 1% 0%

180 52% 23% 10% 4% 2% 1% 1%

185 65% 33% 15% 7% 4% 2% 1%

190 75% 45% 23% 11% 6% 3% 2%

195 83% 57% 33% 17% 10% 5% 3%

200 89% 69% 45% 25% 15% 8% 5%

205 93% 79% 57% 35% 23% 12% 8%

210 96% 86% 69% 48% 33% 18% 12%

215 97% 91% 79% 60% 45% 27% 18%

220 98% 94% 86% 71% 57% 38% 27%

225 99% 96% 91% 80% 69% 50% 38%

230 99% 98% 94% 87% 79% 62% 50%

235 100% 99% 96% 92% 86% 73% 62%

240 100% 99% 98% 95% 91% 82% 73%

245 100% 100% 99% 97% 94% 88% 82%

250 100% 100% 99% 98% 96% 92% 88%

255 100% 100% 100% 99% 98% 95% 92%

260 100% 100% 100% 99% 99% 97% 95%

265 100% 100% 100% 100% 99% 98% 97%

270 100% 100% 100% 100% 100% 99% 98%

275 100% 100% 100% 100% 100% 99% 99%

280 100% 100% 100% 100% 100% 100% 99%

285 100% 100% 100% 100% 100% 100% 100%

290 100% 100% 100% 100% 100% 100% 100%

295 100% 100% 100% 100% 100% 100% 100%

300 100% 100% 100% 100% 100% 100% 100%

*Note: This table provides the estimated probability of passing the state test based on a MAP test score taken during the prior (fall) season. Example: if a fifth grade student scored 200 on a MAP test taken during the fall season, her/his estimated probability of passing the state test is 25%.

Italics represent extrapolated

data.

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READING - Fall (Prior) Season

Estimated Probability of Passing State Test Based on Observed MAP Score

RIT Range 2 3 4 5 6 7 8

120 0% 0% 0% 0% 0% 0% 0%

125 1% 0% 0% 0% 0% 0% 0%

130 1% 0% 0% 0% 0% 0% 0%

135 1% 0% 0% 0% 0% 0% 0%

140 2% 1% 0% 0% 0% 0% 0%

145 4% 1% 0% 0% 0% 0% 0%

150 6% 2% 1% 0% 0% 0% 0%

155 10% 3% 1% 1% 0% 0% 0%

160 15% 4% 2% 1% 1% 0% 0%

165 23% 7% 3% 1% 1% 1% 0%

170 33% 11% 4% 2% 1% 1% 1%

175 45% 17% 7% 4% 2% 2% 1%

180 57% 25% 11% 6% 4% 3% 2%

185 69% 35% 17% 10% 6% 5% 3%

190 79% 48% 25% 15% 10% 8% 4%

195 86% 60% 35% 23% 15% 12% 7%

200 91% 71% 48% 33% 23% 18% 11%

205 94% 80% 60% 45% 33% 27% 17%

210 96% 87% 71% 57% 45% 38% 25%

215 98% 92% 80% 69% 57% 50% 35%

220 99% 95% 87% 79% 69% 62% 48%

225 99% 97% 92% 86% 79% 73% 60%

230 100% 98% 95% 91% 86% 82% 71%

235 100% 99% 97% 94% 91% 88% 80%

240 100% 99% 98% 96% 94% 92% 87%

245 100% 100% 99% 98% 96% 95% 92%

250 100% 100% 99% 99% 98% 97% 95%

255 100% 100% 100% 99% 99% 98% 97%

260 100% 100% 100% 100% 99% 99% 98%

265 100% 100% 100% 100% 100% 99% 99%

270 100% 100% 100% 100% 100% 100% 99%

275 100% 100% 100% 100% 100% 100% 100%

280 100% 100% 100% 100% 100% 100% 100%

285 100% 100% 100% 100% 100% 100% 100%

290 100% 100% 100% 100% 100% 100% 100%

295 100% 100% 100% 100% 100% 100% 100%

300 100% 100% 100% 100% 100% 100% 100%

*Note: This table provides the estimated probability of passing the state test based on a MAP test score taken during the prior (fall) season. Example: if a fifth grade student scored 200 on a MAP test taken during the fall season, her/his estimated probability of passing the state test is 33%.

Italics represent extrapolated

data.

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MATH - Winter (Prior) Season

Estimated Probability of Passing State Test Based on Observed MAP Score

RIT Range 2 3 4 5 6 7 8

120 0% 0% 0% 0% 0% 0% 0%

125 0% 0% 0% 0% 0% 0% 0%

130 0% 0% 0% 0% 0% 0% 0%

135 0% 0% 0% 0% 0% 0% 0%

140 1% 0% 0% 0% 0% 0% 0%

145 1% 0% 0% 0% 0% 0% 0%

150 2% 1% 0% 0% 0% 0% 0%

155 4% 1% 0% 0% 0% 0% 0%

160 6% 2% 1% 0% 0% 0% 0%

165 9% 3% 1% 1% 0% 0% 0%

170 14% 5% 2% 1% 1% 0% 0%

175 21% 8% 4% 1% 1% 0% 0%

180 31% 12% 6% 2% 1% 1% 0%

185 43% 18% 9% 4% 2% 1% 1%

190 55% 27% 14% 6% 4% 2% 1%

195 67% 38% 21% 10% 6% 4% 2%

200 77% 50% 31% 15% 10% 6% 4%

205 85% 62% 43% 23% 15% 9% 6%

210 90% 73% 55% 33% 23% 14% 9%

215 94% 82% 67% 45% 33% 21% 14%

220 96% 88% 77% 57% 45% 31% 21%

225 98% 92% 85% 69% 57% 43% 31%

230 99% 95% 90% 79% 69% 55% 43%

235 99% 97% 94% 86% 79% 67% 55%

240 99% 98% 96% 91% 86% 77% 67%

245 100% 99% 98% 94% 91% 85% 77%

250 100% 99% 99% 96% 94% 90% 85%

255 100% 100% 99% 98% 96% 94% 90%

260 100% 100% 99% 99% 98% 96% 94%

265 100% 100% 100% 99% 99% 98% 96%

270 100% 100% 100% 100% 99% 99% 98%

275 100% 100% 100% 100% 100% 99% 99%

280 100% 100% 100% 100% 100% 99% 99%

285 100% 100% 100% 100% 100% 100% 99%

290 100% 100% 100% 100% 100% 100% 100%

295 100% 100% 100% 100% 100% 100% 100%

300 100% 100% 100% 100% 100% 100% 100%

*Note: This table provides the estimated probability of passing the state test based on a MAP test score taken during the prior (winter) season. Example: if a fifth grade student scored 200 on a MAP test taken during the fall season, her/his estimated probability of passing the state test is 15%.

Italics represent extrapolated

data.

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READING - Winter (Prior) Season

Estimated Probability of Passing State Test Based on Observed MAP Score

RIT Range 2 3 4 5 6 7 8

120 0% 0% 0% 0% 0% 0% 0%

125 0% 0% 0% 0% 0% 0% 0%

130 0% 0% 0% 0% 0% 0% 0%

135 1% 0% 0% 0% 0% 0% 0%

140 1% 0% 0% 0% 0% 0% 0%

145 2% 0% 0% 0% 0% 0% 0%

150 3% 1% 0% 0% 0% 0% 0%

155 4% 1% 1% 0% 0% 0% 0%

160 7% 2% 1% 1% 0% 0% 0%

165 11% 4% 2% 1% 1% 0% 0%

170 17% 6% 3% 2% 1% 1% 0%

175 25% 9% 4% 3% 2% 1% 1%

180 35% 14% 7% 4% 3% 2% 1%

185 48% 21% 11% 7% 5% 4% 2%

190 60% 31% 17% 11% 8% 6% 4%

195 71% 43% 25% 17% 12% 9% 6%

200 80% 55% 35% 25% 18% 14% 9%

205 87% 67% 48% 35% 27% 21% 14%

210 92% 77% 60% 48% 38% 31% 21%

215 95% 85% 71% 60% 50% 43% 31%

220 97% 90% 80% 71% 62% 55% 43%

225 98% 94% 87% 80% 73% 67% 55%

230 99% 96% 92% 87% 82% 77% 67%

235 99% 98% 95% 92% 88% 85% 77%

240 100% 99% 97% 95% 92% 90% 85%

245 100% 99% 98% 97% 95% 94% 90%

250 100% 99% 99% 98% 97% 96% 94%

255 100% 100% 99% 99% 98% 98% 96%

260 100% 100% 100% 99% 99% 99% 98%

265 100% 100% 100% 100% 99% 99% 99%

270 100% 100% 100% 100% 100% 99% 99%

275 100% 100% 100% 100% 100% 100% 99%

280 100% 100% 100% 100% 100% 100% 100%

285 100% 100% 100% 100% 100% 100% 100%

290 100% 100% 100% 100% 100% 100% 100%

295 100% 100% 100% 100% 100% 100% 100%

300 100% 100% 100% 100% 100% 100% 100%

*Note: This table provides the estimated probability of passing the state test based on a MAP test score taken during the prior (winter) season. Example: if a fifth grade student scored 200 on a MAP test taken during the fall season, her/his estimated probability of passing the state test is 25%.

Italics represent extrapolated

data.

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TABLE 5 – CORRELATION COEFFICIENTS BETWEEN MAP AND STATE TEST FOR EACH GRADE AND TEST SUBJECT

Grade Math Correlation Pearson's r

Reading Correlation Pearson's r

3 0.782 0.735 4 0.800 0.725 5 0.816 0.712 6 0.803 0.740 7 0.814 0.747 8 0.805 0.747

* Note: Correlations range from 0 (indicating no correlation between the state test score and the NWEA test score) to 1 (indicating complete correlation between the state test score and the NWEA test score).

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TABLE 6 – PERCENTAGE OF STUDENTS WHOSE PASS STATUS WAS ACCURATELY PREDICTED BY THEIR MAP PERFORMANCE USING REPORTED CUT SCORES

Grade

Sample Size

MAP Accurately Predicted State

Performance

MAP Underestimated State Performance

MAP Overestimated State Performance

Mathematics 3 9633 81.7% 9.7% 8.6% 4 10164 82.8% 8.1% 9.1% 5 10008 83.2% 8.7% 8.1% 6 10448 83.7% 8.8% 7.5% 7 10310 85.6% 7.2% 7.2% 8 10001 83.5% 7.7% 8.8%

Reading 3 9616 80.6% 10.1% 9.3% 4 10163 80.0% 10.1% 9.8% 5 10008 79.5% 9.4% 11.2% 6 10439 80.9% 9.6% 9.4% 7 10281 80.8% 9.2% 10.0% 8 10036 79.8% 10.4% 9.9%

*Note: The third column of this table shows the percentage of students whose Pass/NotPass status was predicted accurately when their state test score was linked to their MAP score based on this linking study. The fourth column shows the percentage of students whose MAP score predicted they would not pass the state benchmark but they did pass. The last column shows the percentage of students whose MAP score predicted they would pass the state benchmark but they did not pass. Due to rounding, percentages may not add to 100%.