The Big Picture
Student Growth Percentiles and Accountability
Future Directions
References
An Introduction to Student Growth Percentiles and the SGP
Package
Damian W. Betebenner
National Center for the Improvement of Educational Assessment
Dover, NH
Albuquerque Public Schools, Albuquerque, New Mexico
November 12th, 2013
Damian W. Betebenner An Introduction to SGPs
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
From a Paucity to a Plethora of Data
The Economist: The Data Deluge
Historical records of student achievement
Historical records of student demographics, teachers, schools,
educational programs, . . .
Stakeholder interest in an examination of this longitudinal data
Interest in examining student achievement over time (student
growth) derives from data availability.
Damian W. Betebenner An Introduction to SGPs
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Describing Student Growth
Measuring student growth, even with a vertical scale, is not a simple
task.
Some believe a vertical scale simplifies the task of measuring
student growth.
Even with an interval (or ratio) scale, growth is not easy to interpret.
Consider, for example, height.
A child might grow 4 inches between ages 3 and 4.
4 inches is a well understood quantity.
The 4 inch increase becomes really meaningful only when understood
alongside the growth of other 3 to 4 year olds.
Student growth percentiles were developed to provide a normative
context for describing student growth.
Damian W. Betebenner An Introduction to SGPs
20 core
ca ca le
le 480
S re 2013
co
20 core
ca ca le
le 480
S re 2013
co
20 core
ca ca le
le 480
S re 2013
co
co
re
le
ca
ro
th
nt
i le 13
ce
er
th
460 re
co
440 le
ca
co
re
th S
ro
le
le
ca
nt
er
ce S
th
460 re
co
440 le
ca
Peer 4 5 4
m i re
ade Sco
Ac cale
201 75% 75 th
Per
400 nt i
ce le G
wth
ro
20 core
ca ca le
le 480
S re 20 13
co
Th
is d 75th
s: dat erive perc
eer 4 5 4
acaa and from ntile
c P = dem co a cu
ic p vers ll the t
m i re eer all
ade Sco g ro
Ac cale
ups
201 75% 75 th
Per
400 nt i
ce le G
wth
ro
20 core
ca ca le
le 480
S re 20 13
co
eer 4 2 6
cPe=
Th
m i r is d 75th
ade Sco
dat erive perc
acaa and from ntile
Ac cale dem co a cu
ic p vers ll the t
2S eer all
g ro
ups
th
Per
400 nt i
ce
le G
wth
ro
20 core
ca ca le
le 480
S re 2013
co
Th
is e
dade 75
a c t a r iv t h
a d a ed p
emnd f er
ic coro cmen
peve atil
errs ll e c
gralltheut
ou
ps
75 th
Pe
40 r ce
0 nt
il e
Gr
ow
th
Sc
0 or
al Sc
Sc 0 0 al
or 52 Sc
Th
is e
dade 75
a c t a r iv t h
a d a ed p
emnd f er
ic coro cmen
peve atil
errs ll e c
gralltheut
ou
ps
% 7 5 th P
40 75 er
ce
0 nt 0
il e
Gr
ow
th
Sc
0 or
al Sc
Sc 0 0 al
or 52 Sc
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Student Growth Percentiles
Should we be surprised with a child’s current achievement given their prior
achievement?
Given a student’s prior scale scores and the associated conditional
density, their current scale score corresponds to a percentile of that
conditional distribution.
This percentile is the student’s growth percentile.
Growth percentiles are closely related to estimating the probability of
observing a student’s current achievement taking account of their
past achievement:
Pr(Current Achievement |Past Achievement ).
As such, growth percentiles describe the rarity of a student’s current
achievement conditional upon their prior achievement.
Damian W. Betebenner An Introduction to SGPs
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Student Growth Percentiles
Should we be surprised with a child’s current achievement given their
prior achievement?
Student growth percentiles answer this question.
Consider a low achieving student with 50th percentile growth and a
high achieving student with 50th percentile growth.
The low achieving student grew at a rate exceeding 50 percent of
similar students.
The high achieving student grew at a rate exceeding just 50 percent of
similar students.
The low achiever’s growth is probabilistically as rare as the high
achiever’s.
Equally rare does not mean equally good.
Judgments about the adequacy of student growth require external
criteria.
Damian W. Betebenner An Introduction to SGPs
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Model for Student Growth Percentiles
Student growth percentiles are calculated using quantile regression
with B-spline smoothing, a generalized additive model.
Quantile regression is used to model the complete distribution of the
response variable (current achievement)
B-spline smoothing is uses to accommodate non-linearity and
heteroscedasticity of the data.
The model/method is descriptive and all about data fit—it’s a data
mining procedure.
The model quantifies distance = rate · time probabilistically.
Damian W. Betebenner An Introduction to SGPs
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Model for Student Growth Percentiles
Conditional Decile Regression Curves Conditional Decile Regression Lines
2006−07 Math: Grade 5 versus 6 2006−07 Math: Grade 5 versus 6
1000 Unsatisfactory Partially Prof. 1000 Unsatisfactory Partially Prof.
Proficient Proficient
Partially Prof. Proficient Advanced Partially Prof. Proficient Advanced
Grade 6 Scale Score Grade 6 Scale Score
Grade 5 Scale Score Grade 5 Scale Score
Damian W. Betebenner An Introduction to SGPs
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Software for Student Growth Percentiles
Student Growth Percentiles and Percentile Growth Trajectories are
calculated using the open source R Software
Environment [R Development Core Team, 2013] and the SGP
package [Betebenner et al., 2013]
In working with state departments of education, the goal is to build
local capacity so analyses can be performed and validated on their
own using software available and easily used by the state.
Colorado, Massachusetts, Indiana, Nevada, Arizona, Wisconsin,
Idaho, Washington, Hawaii, Georgia, West Virginia, Oregon, are
states (that I know of) who have state staff capable of generating the
student growth percentiles together with aggregations that follow
from their calculation.
State ownership/oversight of the SGP calculations has been a big
plus in terms of buy-in from the state, enhancing their ability to
explain and work with local stakeholders.
Damian W. Betebenner An Introduction to SGPs
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Software for Student Growth Percentiles
Creative Commons Share-and-Share Alike License:
Software is open source and developed on the GitHub collaborative
version control system:
https://github.com/CenterForAssessment/SGP
Source code for analyses of each state are version controlled on
GitHub for complete transparency. For example
https://github.com/CenterForAssessment/Colorado
Meta-data (e.g., names of achievement levels, CSEMs, ...) for state
assessment systems is housed within the package and
developed/maintained on GitHub:
https://github.com/CenterForAssessment/SGPstateData
Damian W. Betebenner An Introduction to SGPs
Student Growth Percentile Adoption
Adopted Model
Considering Adoption
Investigating Model
The Data Revolution
The Big Picture
Describing Student Growth
Student Growth Percentiles and Accountability
Student Growth Percentiles
Future Directions
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Establishing growth-standards based upon growth-norms
The most common adequacy criterion are judging growth toward an
achievement goal (i.e., growth-to-standard).
Results from student growth percentile analyses can be used to
calculate percentile growth trajectories for each student.
These trajectories indicate what future rates of growth will lead to
and are used to make adequacy judgments.
This growth-to-standard approach was approved as part of
Colorado’s successful application to the Growth Model Pilot
Program.
Damian W. Betebenner An Introduction to SGPs
Advanced Reading
Achievement
Very High
DEMO Reading
● Scale Score
High
Typical
Proficient Low Growth
Level Percentiles
Very Low
● Very High 81st − 99th
High 61st − 80th
Part Proficient Typical 40th − 60th
Low 20th − 39th
Very Low 1st − 19th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7
Scale Score 449 533 579 602
Achievement Level Unsatisfactory Part Proficient Part Proficient Proficient Achievement
Growth Percentile 69 85 74
Growth Level High Very High High Growth
Billy Gonzales North End Middle School
How to interpret this student
growth & achievement report Math
Advanced Very High
Achievement
DEMO High
● DEMO Math
● Typical Scale Score
Scale Score ●
Low
● Growth
Proficient Very Low Level Percentiles
DEMO Very High 81st − 99th
Achievement High 61st − 80th
Levels Part Proficient
Typical 40th − 60th
Low 20th − 39th
Very Low 1st − 19th
Unsatisfactory
Student
Growth Grade 3 Grade 4 Grade 5 Grade 6 Grade 7
Percentile Scale Score 438 447 489 495
Achievement Level Proficient Part Proficient Part Proficient Part Proficient Achievement
Growth Percentile 18 64 44
Growth Level Very Low High Typical Growth
Suggested Uses
Review past growth to assess
student academic progress toward Advanced Reading
DEMO achievement goals.
Achievement
● Develop remediation or enrich− Very High
DEMO Reading
ment plans based on rate of ● Scale Score
High
growth needed to reach higher ● Typical
DEMO achievement levels. Proficient Low Growth
Level Percentiles
● Identify the rate of progress Very Low
needed in order to reach or ● Very High 81st − 99th
maintain proficient status High 61st − 80th
on the DEMO next year. Part Proficient Typical 40th − 60th
Low 20th − 39th
Very Low 1st − 19th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7
Scale Score 449 533 579 602
Achievement Level Unsatisfactory Part Proficient Part Proficient Proficient Achievement
Growth Percentile 69 85 74
Growth Level High Very High High Growth
For more information please visit the Student Growth Percentiles (SGP) at centerforassessment.github.io/SGP/ or contact dbetebenner@nciea.org
Cooperatively developed by the SGP & the Center for Assessment, Inc. Distributed by the SGP.
Advanced Reading
● Move Up
Achievement
Target
DEMO Reading
● Scale Score
Keep Up
● Target
Proficient Growth
Level Percentiles
● Very High 81st − 99th
High 61st − 80th
Part Proficient Typical 40th − 60th
Low 20th − 39th
Very Low 1st − 19th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7
Scale Score 449 533 579 602
Achievement Level
Achievement Target
Unsatisfactory Part Proficient Part Proficient Proficient
Proficient (620)/Advanced (661)
Achievement
Growth Percentile 69 85 74
Growth Level
Growth Target
High Very High High
Keep Up (76)/Move Up (99)
Growth
Advanced Reading
● Move Up
Achievement
Target
DEMO Reading
● Scale Score
Keep Up
● Target
Proficient ●
Catch Up ●
Target
Growth
Level Percentiles
● Very High 81st − 99th
High 61st − 80th
Part Proficient Typical 40th − 60th
Low 20th − 39th
Very Low 1st − 19th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7
Scale Score 449 533 579 602
Achievement Level
Achievement Target
Unsatisfactory Part Proficient Part Proficient Proficient
Proficient (592) Proficient (620)/Advanced (661)
Achievement
Growth Percentile 69 85 74
Growth Level
Growth Target
High Very High High
Catch Up (60) Keep Up (76)/Move Up (99)
Growth
Demonstration: 2012−2013 Mathematics
Norm & Criterion Referenced Growth & Achievement
Percentile Growth Trajectory
Scale Score
2012−2013 Achievement Percentile
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Grade 10
Demonstration: 2012−2013 Mathematics
Norm & Criterion Referenced Growth & Achievement
Percentile Growth Trajectory
Scale Score
2012−2013 Achievement Percentile
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Grade 10
Demonstration: 2012−2013 Mathematics
Norm & Criterion Referenced Growth & Achievement
Percentile Growth Trajectory
Scale Score
2012−2013 Achievement Percentile
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Grade 10
The Big Picture
Student Growth Percentiles and Accountability
School Accountability
Future Directions
References
Going from Students to Schools
It’s of interest to examine schools where students demonstrate, on
average, extraordinarily high and low student growth.
To summarize the student growth percentiles associated with a
school (or other grouping) calculate the median of the student
growth percentiles.
If students were randomly assigned to schools, expect to see a
median of 50.
Values greatly above or below 50 are of interest in identifying best
practices or providing extra support.
Examining growth with achievement sheds new light on school
performance.
Damian W. Betebenner An Introduction to SGPs
DEMONSTRATION School Performance
DEMO Growth & Achievement 2012−2013 DEMO Mathematics
Higher Achievement Higher Achievement School Size
2012−2013 Percent at/above Proficient
Lower Growth Higher Growth 50 Students
100 Students
250 Students
500 Students
Achievement
Lower Growth Higher Growth
Lower Achievement Lower Achievement
Growth 2012−2013 Median Student Growth Percentile
DEMONSTRATION School Performance
DEMO Growth & Prior Achievement 2012−2013 DEMO Mathematics
2011−2012 Prior Percent at/above Proficient
Higher Achievement Higher Achievement School Size
Lower Growth Higher Growth 50 Students
100 Students
250 Students
500 Students
Achievement
Lower Growth Higher Growth
Lower Achievement Lower Achievement
Growth 2012−2013 Median Student Growth Percentile
DEMONSTRATION School Performance
DEMO Growth & Achievement 2012−2013 DEMO Reading
Higher Achievement Higher Achievement School Size
2012−2013 Percent at/above Proficient
Lower Growth Higher Growth 50 Students
100 Students
250 Students
500 Students
Achievement
Lower Growth Higher Growth
Lower Achievement Lower Achievement
Growth 2012−2013 Median Student Growth Percentile
DEMONSTRATION School Performance
DEMO Growth & Prior Achievement 2012−2013 DEMO Reading
2011−2012 Prior Percent at/above Proficient
Higher Achievement Higher Achievement School Size
Lower Growth Higher Growth 50 Students
100 Students
250 Students
500 Students
Achievement
Lower Growth Higher Growth
Lower Achievement Lower Achievement
Growth 2012−2013 Median Student Growth Percentile
The Big Picture
Student Growth Percentiles and Accountability
Web 2.0 Technologies
Future Directions
References
Web 2.0: Data Visualization and Social Networking
The Colorado Department of Education and the Center for
Assessment have been working for the last two years on developing
next generation data visualization to accompany growth model data.
The goal: Transform conversations about education through active
engagement with data (i.e., evidence).
Our efforts have received tremendous interest and recognition:
Recognized by Adobe for innovative uses of their technology as an
Adobe Max Award finalist in October, 2009.
2010 NCME Award for Outstanding Dissemination of Educational
Measurement Concepts to the Public.
14 states signing MOUs to co-develop a cloud-based reporting
platform in a non-proprietary fashion.
Colorado recently devoted $2.5 million of stimulus funds to the
development efforts
Damian W. Betebenner An Introduction to SGPs
The Big Picture
Student Growth Percentiles and Accountability
Web 2.0 Technologies
Future Directions
References
The Decade of Data Visualization
Chart Wars http://infosthetics.com/archives/2010/01/
chart_wars_the_political_power_of_data_
visualization.html
Hans Rosling/Gapminder
http://www.youtube.com/watch?v=jbkSRLYSojo
Journalism in the Age of Data
http://datajournalism.stanford.edu/
Damian W. Betebenner An Introduction to SGPs
The Big Picture
Student Growth Percentiles and Accountability
Web 2.0 Technologies
Future Directions
References
Web 2.0: Data Visualization and Social Networking
With a collaborative spirit, with a collaborative platform where people can
upload data, explore data, compare solutions, discuss the results, build
consensus, we can engage passionate people, local communities, media
and this will raise–incredibly–the amount of people who can understand
what is going on.
And this would have fantastic outcomes: the engagement of people,
especially new generations; it would increase knowledge, unlock
statistics, improve transparency and accountability of public policies,
change culture, increase numeracy, and in the end, improve democracy
and welfare.
E. Giovannini, Chief Statistician, OECD. June 2007
Damian W. Betebenner An Introduction to SGPs
The Big Picture
Student Growth Percentiles and Accountability
Future Directions
References
References
Betebenner, D. W., Van Iwaarden, A., Domingue, B., and Shang, Y.
SGP: An R Package for the Calculation and Visualization of Student
Growth Percentiles & Percentile Growth Trajectories.
R package version 1.2-0.0.
R Development Core Team (2013).
R: A language and environment for statistical computing.
R Foundation for Statistical Computing, Vienna, Austria.
Damian W. Betebenner An Introduction to SGPs
About this copy
An Introduction to Student Growth Percentiles and the SGP Package — Albuquerque, November 12, 2013.
This is an image-based copy of the original beamer slides; builds and animations are flattened.