What is a Z Score?. The State’s Waiver from NCLB All schools will achieve 85% proficiency for all students in all subjects (as measured on a statewide

What is a Z Score?

The State’s Waiver from NCLB

All schools will achieve 85% proficiency for all students in all subjects (as measured on a statewide assessment) by 2022..

Reward Schools◦ Highest Performing◦ Beating the Odds◦ Exceeding 85%◦ Highest Progress

Focus Schools◦ The ten percent of schools with the largest gaps in student

results (as identified by statewide assessments) between high and low-achieving students within a school. (Approximately 356 schools)

Priority Schools◦ Schools in the bottom five percent on the state’s Top-to-Bottom

list. These schools are placed under the jurisdiction of the School Reform Office and are required to rapidly turnaround, transform, restart or close. (Approximately 150 schools)

Materials provided by MDE

Ranking SchoolsUnderstanding the Use of Z-Scores in the Top to Bottom

RankingSelected Slides from Michigan Department of Education

Thoughts on Ranking Schools

• To rank schools:–Have to compare them on a similar metricExample:MEAP Scale Score for 3rd grade: 315MME Scale Score for 11th grade: 1100

How do you compare a school of 3rd graders to a school of 11th graders?

Example:

Can’t add up all scale scores and divide by number of students, because the scores have different meanings

Need to put all assessment scores on the same metric so that you can combine:◦Across grades◦Across test types◦Across subjects

The answer: Z-scores!

We can use z-scores to:◦Level the playing field across grade levels and

subjects◦Talk about a student’s score in terms of

distance from the statewide average for all similar students

◦Talk about a school value (such as average achievement or improvement) in terms of that school’s distance from the statewide average for all similar schools

Z-Score “Cheat Sheet”• Z-scores are centered around zero• Positive numbers mean the student or

school is above the state average• Negative numbers mean the student or

school is below the state average

0 1 2 3-1

-2

-3

State Average Better than state

average….…Worse than state

average

Z-Score Examples

• Your school has a z-score of 1.5. You are better than the state average.

0 1 2 3-1

-2

-3



average

Z-score of 1.5

Z-Score Examples• Your school has a z-score of .2. You are

better than the state average, but not by a lot.

0 1 2 3-1

-2

-3



average

Z-score of 1.5

Z-score of 0.2

Z-Score Examples• Your school has a z-score of -2.0. You are

very far below state average.

0 1 2 3-1

-2

-3



average

Z-score of 1.5

Z-score of 0.2

Z-score of -2.0

How do we use Z-Scores in the TTB? Understanding Z-Scores

Two main ways

1) To compare student test scores to other student test scores, and to combine all those test scores into school-level values

2) To compare school-level values (like school achievement, improvement, and gaps) to other schools

How do we get Standardized Scale Scores for Each Student?

• Step #1: Take each student’s score on the test they took and compare that score to the statewide average for students who took that same test in the same grade and year

• This creates a student-level z-score for each student in each content area– Compare• MEAP to MEAP• MEAP-Access to MEAP-Access• MME to MME• MI-Access– Participation to Participation– Supported Independence to Supported Independence– Functional Independence to Functional Independence

What do we do with those standardized scores?

• Step #2: Once each student has a z-score for each content area (based on the test they took), we take all of the students in a each school, and rank order the students within the school.– Z-scores will have come from different tests, and compare

students to statewide average for that grade, test, and subject– But they can now be combined for the school

• Step #3: Add up all z-scores and take the average. This is now the average standardized student scale score.

• Step #4: Define the top and bottom 30% subgroups, based on that rank ordering.

Student Test Taken Z-score

Tommy Mi-Access, Participation

2.5

Sally MEAP 2.0

Maura MI-Access, SI 1.9

Fred MEAP 1.5

Ichabod MEAP-Access 1.0

Freud MEAP 0.8

Maybelle MI-Access, FI 0.7

Destiny MEAP 0.5

Harold MEAP -0.2

Bickford MI-Access, FI -0.5

Talledaga MEAP-Access -0.7

Francine MEAP -1.2

Joey MEAP -1.9

William MEAP -2.2


Tommy Mi-Access, Participation

2.5

Sally MEAP 2.0


Fred MEAP 1.5


Freud MEAP 0.8


Destiny MEAP 0.5

Harold MEAP -0.2



Francine MEAP -1.2

Joey MEAP -1.9

William MEAP -2.2

Average Z-score (average standardized student

scale score): 0.28(sum all z-scores, divide

by 15)


Tommy Mi-Access, Participation 2.5

Sally MEAP 2.0


Fred MEAP 1.5


Freud MEAP 0.8


Destiny MEAP 0.5

Harold MEAP -0.2



Francine MEAP -1.2

Joey MEAP -1.9

William MEAP -2.2

Top 30%

Bottom 30%

How do we compare school z-scores?

• We calculate school-level values for the following components in every subject:–Achievement– Improvement–Achievement gap

• Then we calculate overall values for each subject that combine those three components

• The school z-scores compare each school’s value to the average value for other similar schools

End of MDE Material

How is the TTB ranking calculated?

Each subject area test is 20%If a building awards a diploma, the

graduation rate is 10% and each of the five content areas are weighted at 18%.

If a building doesn’t have a content area, the weight of the other content areas are modified equally to reach 100%.

Z Scores and TTB Ranking: 2014How does it look in a real Focus school?

Pleasantview Middle School

Year Publicized

Overall School Index

TTB Percentile Rank

2014 - Focus Year 1

-0.8172 172013 -0.6609 23

2012 -0.3120 34

Mathematics

E/MS Math

4 5 6

2-Yr Ave % Proficient: 40.6133 Achievement: 0.0441 Z: 0.1934 0.50

15 16 7 16 19 20

-1.897836025

-1.897836

025 Improvement (PLC): -0.2534 Z: -1.8978 0.25 Index: -0.6158 Z: -0.8966

17 18 1

Achievement Gap: -2.1434 Z: -0.9523 0.25

Reading

E/MS

Reading

24 25 26

2-Yr Ave % Proficient: 64.4008 Achievement: -0.0615 Z: -0.0952 0.50

35 36 27 36 39 40

-1.335238232

-1.335238

232 Improvement (PLC): 0.1354 Z: -1.3352 0.25 Index: -0.6858 Z: -0.9549

37 38 1


Science

E/MS

Science

44 45 46


47 54 57 58

Improvement: -0.0143 Z: -0.1309 0.25 Index: -0.3075 Z: -0.5202

55 56 1


Social Studies

E/MS

Socia

l St

udies

62 63 64

2-Yr Ave % Proficient: 32.9272 Achievement: 0.1074 Z: 0.3052 0.50

65 72 75 76


73 74 1


Writing

E/MS

Writing

80 81 82


83 90 93 94


91 92 1


Trend DataTTB Rankings 2012-2014

Pleasantview Middle School School Z Score Analysis: 2012 - 2014

Content Year Achievement Improvement Gap

Mathematics2014 0.1934 -1.8978 -0.9523

2013 0.4456 -1.4322 -0.7497

2012 -0.6347 -1.3620 -0.8680

Reading2014 -0.0952 -1.3352 -1.2176

2013 0.0570 -1.3708 -0.9900

2012 0.2543 -0.7935 0.0482

Science2014 -0.0391 -0.1309 -1.0211

2013 0.0845 -1.7366 -0.3119

2012 0.1892 -0.7528 0.1909

Social Studies2014 0.3052 -1.0947 -1.1288

2013 0.5150 -0.1001 -0.8572

2012 0.5978 -0.5439 -0.2304

Writing2014 -0.2100 -1.6569 -0.4447

2013 -0.2654 -1.9208 -0.6541

2012 -0.3072 -2.1913 -0.7709

Table Talk

How would you explain your school’s TTB ranking to building administrators? Teachers?

How might you assist your school in explaining these data to parents? School board?

What further assistance or questions do you have around the Z score and the Top to Bottom Ranking?

Documents

What is a Z Score?. The State’s Waiver from NCLB All schools will achieve 85% proficiency for all students in all subjects (as measured on a statewide