Intro
Growth & Accountability: Part I
Growth & Accountability: Part II
Student Growth Percentiles and Accountability
References
New Directions for Student Growth Models
Damian W. Betebenner
National Center for the Improvement of Educational Assessment
Dover, NH
Wichita, Kansas December 13th, 2010
Damian W. Betebenner New Directions for Student Growth Models
Intro
Growth & Accountability: Part I
Growth & Accountability: Part II
Student Growth Percentiles and Accountability
References
About Me
Dr. Damian Betebenner, PhD
- Senior Associate at the Center for Assessment (NCIEA).
- Developed student growth percentiles and percentile growth
trajectories to help states and educational associations employ
student growth in decision
making [Betebenner, 2008, Betebenner, 2009].
- Currently refining and sharing these techniques with other
states including Colorado, Massachusetts, Indiana, Virginia and
15 other states in various stages of investigation/adoption.
Damian W. Betebenner New Directions for Student Growth Models
Intro
Growth & Accountability: Part I
Growth & Accountability: Part II
Student Growth Percentiles and Accountability
References
About Today’s Talk
On Questions John Tukey
It is better to have an approximate answer to the right question than a precise answer to the
wrong question.
On Statistical Models George E. P. Box
All models are wrong but some are useful.
On Understanding Aristotle
We understand best those things we see emerge from their very beginnings.
On Accountability Sherlock Holmes
It is a capital mistake to theorize before you have all the evidence. It biases the judgment.
On Theories of Action Confucius
Tell me and I will forget, show me and I will remember, involve me and I will understand.
Damian W. Betebenner New Directions for Student Growth Models
Intro
Growth & Accountability: Part I Why Growth?
Growth & Accountability: Part II Different Models/Different Questions
Student Growth Percentiles and Accountability Relevant Questions/Concepts
References
The Attractiveness of Growth
What is growth and why measure it?
Student learning is a central goal of education.
Assessments of student achievement provide evidence of the
current status of student knowledge and understanding.
Learning is demonstrated by growth in student achievement
from one point in time to another point in time–not by status at
either point time alone.
Damian W. Betebenner New Directions for Student Growth Models
Intro
Growth & Accountability: Part I Why Growth?
Growth & Accountability: Part II Different Models/Different Questions
Student Growth Percentiles and Accountability Relevant Questions/Concepts
References
Guiding Questions
Growth/Value-Added models address specific questions
Different growth analysis techniques often address different but
related different questions.
It is critical to understand these different questions.
Different questions lead to different conversations which lead to
different uses and outcomes.
Changing conversations about education
Starting with the right questions simplifies development and
motivating the proper use of the growth model results.
The questions set the table for those conversations.
Yen (2007) for an excellent list of questions derived from a
survey of parent, teachers and administrators
Damian W. Betebenner New Directions for Student Growth Models
Intro
Growth & Accountability: Part I Why Growth?
Growth & Accountability: Part II Different Models/Different Questions
Student Growth Percentiles and Accountability Relevant Questions/Concepts
References
What are the relevant questions for parents?
Yen (2007), from a state survey of parents, teachers and administrators,
compiled a list of frequently voiced questions/concerns by stakeholder
group.
Parent Questions
Did my child make a year’s worth of progress in a year?
Is my child growing appropriately toward meeting state
standards?
Is my child growing as much in Math as Reading?
Did my child grow as much this year as last year?
Damian W. Betebenner New Directions for Student Growth Models
Intro
Growth & Accountability: Part I Why Growth?
Growth & Accountability: Part II Different Models/Different Questions
Student Growth Percentiles and Accountability Relevant Questions/Concepts
References
What are the relevant questions for teachers?
Yen (2007), from a state survey of parents, teachers and administrators,
compiled a list of frequently voiced questions/concerns by stakeholder
group.
Teacher Questions
Did my students make a year’s worth of progress in a year?
Did my students grow appropriately toward meeting state
standards?
How close are my students to becoming Proficient?
Are there students with unusually low growth who need special
attention?
Damian W. Betebenner New Directions for Student Growth Models
Intro
Growth & Accountability: Part I Why Growth?
Growth & Accountability: Part II Different Models/Different Questions
Student Growth Percentiles and Accountability Relevant Questions/Concepts
References
What are the relevant questions for administrators?
Yen (2007), from a state survey of parents, teachers and administrators,
compiled a list of frequently voiced questions/concerns by stakeholder
group.
Administrator Questions
Did the students in our district/school make a year’s worth of
progress in all content areas?
Are our students growing appropriately toward meeting state
standards?
Does this school/program show as much growth as that one?
Can I measure student growth even for students who do not
change proficiency categories?
Can I pool together results from different grades to draw
summary conclusions?
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Growth & Accountability
Growth versus Status
Enthusiasm for growth in accountability stems from the belief
that growth and teacher/school quality are more closely related
than status.
Enthusiasm for growth also stems from its potential diagnostic
uses.
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Growth & Accountability
Fundamental Premise
“Good” schools/teachers bring about growth in student achievement
in excess of that found at “bad” schools/teachers.
The inherent believability of this premise is at the heart of current
enthusiasm to incorporate growth models into accountability
systems.
Note that current NCLB accountability invokes the same premise
(with achievement substituted for growth).
“Good schools/teachers” are commonly referred to as highly
effective schools/teachers.
It is critical to understand the distinction between growth and
effectiveness.
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Value-added Analyses/Inferences
Who/What is responsible for student growth?
Often, analyses of student growth attempt to determine the amount
of student progress/growth that can be attributed to the school or
teacher.
Called Value-added analyses, these techniques attempt to estimate
the teacher/school contribution to student achievement.
A value-added analysis quantifies effectiveness—purporting to
measure the impact on achievement that this school or teacher or
program would have, on average, upon similar students assigned to
them.
These models and their effectiveness claims are controversial for a
number of reasons (EPI (2010), NRC/NAE (2010), Braun (2005),
Rubin and Stuart (2004)) .
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Value-added Analyses/Inferences
Who/What is responsible for student growth?
What is a “value-added assessment” or a “value-added model”.
Value-added is an inference – a causal conclusion drawn from the
data.
Value-added isn’t a type of statistical model or type of assessment (if
I showed you the statistical model formulation or an assessment,
from the model formulation or assessment you wouldn’t be able to
tell me whether it’s value-added).
All growth models can be used for value-added purposes but not
vice-versa.
The question is whether the inference/conclusion is sound. This is
where the detective work begins.
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Descriptive Questions
Note that the questions from Yen’s (2007) survey are primarily
descriptive.
The questions are only peripherally associated with causality.
High stakes accountability has transformed questions about student
growth into questions about responsibility/cause: Teacher and
School Effectiveness.
Beginning with description doesn’t prevent subsequent discussions
about responsibility/cause.
Beginning with responsibility/cause often prevents discussions about
description.
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
Model & Software for Student Growth Percentiles
References
Criterion Referenced Growth
Descriptive Accountability
Accountability system results can have value without making
causal inferences about school quality, solely from the results of
student achievement measures and demographic
characteristics. Treating the results as descriptive information
and for identification of schools that require more intensive
investigation of organizational and instructional process
characteristics are potentially of considerable value. Rather
than using the results of the accountability system as the sole
determiner of sanctions for schools, they could be used to flag
schools that need more intensive investigation to reach sound
conclusions about needed improvements or judgments about
quality [Linn, 2008, p. 21].
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
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 New Directions for Student Growth Models
600 co
09 600 re
le
ca le ca
S re 10
co
600 co
09 600 re
le
ca le ca
S re 10
co
600 co
09 600 re
le
ca le ca
S re 10
co
co
th
re
ro
i le
le
ce
nt ca
er
th
re
600 co
le
ca
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
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 New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
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 90th percentile growth and a
high achieving student with 10th percentile growth.
The low achieving student grew at a rate exceeding 90 percent of
similar students.
The high achieving student grew at a rate exceeding just 10 percent of
similar students.
The low achiever’s growth is more exemplary (probabilistically) than
the high achiever’s.
Judgments about the adequacy of student growth require external
criteria.
Damian W. Betebenner New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
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, 2010] and the SGP
package [Betebenner, 2010]
In working with state departments of education, the goal is to build
state capacity so states can perform and validate their own analyses
using software available and easily used by the state.
Colorado, Massachusetts, Indiana, and Wisconsin are four 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 New Directions for Student Growth Models
Value-Added
Intro
Description, Inference, and Causality
Growth & Accountability: Part I
Describing Student Growth
Growth & Accountability: Part II
Student Growth Percentiles
Student Growth Percentiles and Accountability
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 New Directions for Student Growth Models
Advanced Reading
High
Achievement
CSAP Reading
● Typical
Scale Score
Proficient Growth
Low
● Level Percentiles
High 66th − 99th
Typical 35th − 65th
Part Proficient
● Low 1st − 34th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Next Year
Scale Score 462 539 563 609
Achievement Level Unsatisfactory Part Proficient Part Proficient Proficient Achievement
Growth Percentile 66 66 90
Growth Level High High High Growth
Example Student 12 (1234567812) Sample Middle School
Advanced
Math
Achievement
High
CSAP Math
● Scale Score
Typical
● Growth
Proficient
● Level Percentiles
Low
High 66th − 99th
● Typical 35th − 65th
Part Proficient
Low 1st − 34th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Next Year
Scale Score 379 388 444 462
Achievement Level Part Proficient Part Proficient Part Proficient Part Proficient Achievement
Growth Percentile 16 69 51
Growth Level Low High Typical Growth
Advanced Reading
High
Achievement
CSAP Reading
● Typical
Scale Score
Proficient Growth
Low
● Level Percentiles
High 66th − 99th
Typical 35th − 65th
Part Proficient
● Low 1st − 34th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Next Year
Scale Score 462 539 563 609
Achievement Level Unsatisfactory Part Proficient Part Proficient Proficient Achievement
Growth Percentile 66 66 90
Growth Level High High High Growth
Advanced
Writing
Achievement
High
CSAP Writing
● Scale Score
Typical
● Growth
Proficient
Level Percentiles
● Low
High 66th − 99th
Part Proficient ● Typical 35th − 65th
Low 1st − 34th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Next Year
Scale Score 425 449 469 504
Achievement Level Part Proficient Part Proficient Part Proficient Part Proficient Achievement
Growth Percentile 55 53 79
Growth Level Typical Typical High Growth
Copyright 2009, Colorado Department of Education/Center for Assessment, Inc.
2008 CSAP Mathematics
Growth and Achievement Chart
2008 Achievement Percentile Percentile Growth Trajectory
Scale Score
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Grade 10
Intro
Growth & Accountability: Part I School Accountability
Growth & Accountability: Part II Growth & Effectiveness
Student Growth Percentiles and Accountability Concluding Remarks
References
Going from Students to Schools/Classrooms
It’s of interest to examine schools or classrooms/teachers 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 New Directions for Student Growth Models
District C: 2008 CSAP Math School Results
Student Growth versus Student Achievement by Percent Free/Reduced Lunch
School Percent
Higher Achievement Higher Achievement Free/Reduced Lunch
Lower Growth Higher Growth
Percent at/above Proficient in School
Less than 20 percent
● 20 to 40 percent
● 40 to 60 percent
● 60 to 80 percent
● More than 80 percent
School Size
50 Students
100 Students
200 Students
30 500 Students
1,000 Students
10 Lower Growth Higher Growth
Lower Achievement Lower Achievement
Median of Student Growth Percentiles in School
Intro
Growth & Accountability: Part I School Accountability
Growth & Accountability: Part II Growth & Effectiveness
Student Growth Percentiles and Accountability Concluding Remarks
References
Growth, Effectiveness, and Value-Added
“Good schools” are often called highly effective schools.
What’s the relationship between growth and effectiveness?
Effectiveness indicates who/what is responsible for the growth
(value-added models).
RttT has placed teacher responsibility for student progress as a
primary issue.
In teacher performance evaluations, even when large scale
assessment results are available, depending upon the state they
constitute, on average, about a third of the overall teacher rating.
Damian W. Betebenner New Directions for Student Growth Models
2009 CSAP Elementary School Mathematics:
School Poverty by School Achievement (r = −0.71)
80 Higher Achievement
Percent at/above Proficient
Lower Achievement
Percent Free/Reduced Lunch Students at School
2009 CSAP Elementary School Mathematics:
School Poverty by School Median SGP (r = −0.22)
80 Higher Average Growth
Median Student Growth Percentile
20 Lower Average Growth
Percent Free/Reduced Lunch Students at School
2009 CSAP Elementary School Reading:
School Poverty by School Median SGP (r = −0.25)
80 Higher Average Growth
Median Student Growth Percentile
20 Lower Average Growth
Percent Free/Reduced Lunch Students at School
Economic Disadvantage vs School Effectiveness
TN Elementary Schools 2008
Average Yearly Achievement Gain 1
Math & Reading/Language Arts in Z units from
TN Current State Average
Percent Free & Reduced Lunch
Intro
Growth & Accountability: Part I School Accountability
Growth & Accountability: Part II Growth & Effectiveness
Student Growth Percentiles and Accountability Concluding Remarks
References
What’s Next?
Colorado, Massachusetts, and Indiana have publicly released
growth results.
The response has been overwhelmingly positive.
Calculating of the quantities is the easy part. Getting people to
understand them and use them correctly is the hard part.
Colorado, Massachusetts, Indiana, Virginia, and other states are
investigating a multi-state platform for data visualization and
reporting built from a common growth analysis.
Damian W. Betebenner New Directions for Student Growth Models
The Colorado Growth Model
Adopted Model
Near Model Adoption
Interested in Model
Intro
Growth & Accountability: Part I
Growth & Accountability: Part II
Student Growth Percentiles and Accountability
References
References
Betebenner, D. W. (2008).
Toward a normative understanding of student growth.
In Ryan, K. E. and Shepard, L. A., editors, The Future of Test-Based
Educational Accountability, pages 155–170. Taylor & Francis, New
York.
Betebenner, D. W. (2009).
Norm- and criterion-referenced student growth.
Educational Measurement: Issues and Practice, 28(4):42–51.
Betebenner, D. W. (2010).
SGP: Student Growth Percentile and Percentile Growth
Projection/Trajectory Functions.
R package version 0.0-6.
Braun, H. I. (2005).
Using student progress to evaluate teachers: A primer on
value-added models.
Technical report, Educational Testing Service, Princeton, New
Jersey.
Economic Policy Institute (2010).
Problems with the use of student test scores to evaluate teachers.
Technical report, Washington, D.C.
Downloaded August 30th, 2010 from
http://epi.3cdn.net/724cd9a1eb91c40ff0_hwm6iij90.pdf.
Linn, R. L. (2008).
Educational accountability systems.
In The Future of Test-Based Educational Accountability, pages 3–24.
Taylor & Francis, New York.
National Research Council and National Academy of Education
Getting value of out value-added: Report of a workshop.
Technical report, Washington, D.C.
Commitee on Value-Added Methodology for Instructional
Improvement.
R Development Core Team (2010).
R: A language and environment for statistical computing.
R Foundation for Statistical Computing, Vienna, Austria.
Rubin, D. B., Stuart, E. A., and Zanutto, E. L. (2004).
A potential outcomes view of value-added assessment in education.
Journal of Educational and Behavioral Statistics, 29(1):103–116.
Yen, W. M. (2007).
Vertical scaling and No Child Left Behind.
In Dorans, N. J., Pommerich, M., and Holland, P. W., editors, Linking
and Aligning Scores and Scales, pages 273–283. Springer, New
York.
Damian W. Betebenner New Directions for Student Growth Models
About this copy
New Directions for Student Growth Models — Kansas Department of Education, December 13, 2010.
This is an image-based copy of the original beamer slides; builds and animations are flattened.