The Big Picture
Why Growth?
Growth and Accountability
Future Directions
References
Student Growth Percentiles
Damian W. Betebenner
@DBetebenner
DBetebenner@nciea.org
National Center for the Improvement of Educational Assessment
Dover, NH
Wisconsin Rapids, Wisconsin
July 24th, 2012
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
Growth and Accountability
Future Directions
References
About Me
Damian Betebenner Senior Associate National Center for the
Improvement of Educational Assessment. Developed
student growth percentiles and percentile growth
trajectories to help states and educational associations
employ student growth in decision
making [Betebenner, 2008, Betebenner, 2009,
Betebenner, 2012]. Currently refining and sharing these
techniques with approximately two dozen other states.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
The Data Revolution
Growth and Accountability
Lessons Learned
Future Directions
References
From a Paucity to a Plethora of Data
The Economist: The Data Deluge
More and better organized data: mega, giga, tera, peta, exa,
zetta, yotta!
Historical records of student achievement
Linkage of student achievement to 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.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
The Data Revolution
Growth and Accountability
Lessons Learned
Future Directions
References
A Recurring Metaphor
Data as a window and a mirror
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
The Data Revolution
Growth and Accountability
Lessons Learned
Future Directions
References
Lessons Learned
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.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
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.
Growth Mindset (Dweck:2006). Students with a “growth
mindset” outperform those with a “fixed mindset”.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
References
Guiding Questions
Growth models address specific questions
Different growth analysis techniques are good at answering
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
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
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?
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
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?
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
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?
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
References
What are the relevant questions for policy makers?
Policy Maker Questions
Can/how should student growth be used in judgments of
educator quality?
Can/how should student growth be used in judgments of
education (e.g., school) quality?
Are students on track for career and college readiness?
What adjustments for student demographics need to be
considered?
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
References
Describing Student Growth
Measuring and communicating student growth is not a simple task.
Some believe creating the perfect scale (e.g., height in inches)
solves 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
norm-referenced context for describing student growth.
D. W. Betebenner Student Growth Percentiles
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The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
References
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:
SGP = Probability of Current Achievement given Prior Achievement
As such, growth percentiles describe the rarity of a student’s current
achievement taking account of their prior achievement.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
References
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 as exemplary (in a probabilistic sense) as
the high achiever’s.
However: Judgments about the adequacy of student growth require
external criteria.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? Relevant Questions/Concepts
Growth and Accountability Describing Student Growth
Future Directions Student Growth Percentiles
References
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.
D. W. Betebenner Student Growth Percentiles
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
The Big Picture
Why Growth? School Accountability
Growth and Accountability Student Growth and Value-Added
Future Directions Description, Inference, and Causation
References
Going from Students to Groups of Students
It’s of interest to examine schools/classrooms/groups where
students demonstrate, on average, extraordinarily high and low
student growth.
To summarize the student growth percentiles associated with a
groups of students (for example, a school) calculate the median of
the student growth percentiles.
If students were randomly selected, 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.
D. W. Betebenner Student Growth Percentiles
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
The Big Picture
Why Growth? School Accountability
Growth and Accountability Student Growth and Value-Added
Future Directions Description, Inference, and Causation
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.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? School Accountability
Growth and Accountability Student Growth and Value-Added
Future Directions Description, Inference, and Causation
References
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.
Value-added models quantify effectiveness—purporting to measure
the impact on achievement that this school or teacher 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)) .
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? School Accountability
Growth and Accountability Student Growth and Value-Added
Future Directions Description, Inference, and Causation
References
Value-added Analyses/Inferences
Who/What is responsible for student growth?
Value-added models are better described as effectiveness models
than as growth models.
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.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? School Accountability
Growth and Accountability Student Growth and Value-Added
Future Directions Description, Inference, and Causation
References
Descriptive Questions
Note that the questions from Yen’s (2007) survey are primarily
descriptive.
The questions are only peripherally associated with causation.
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.
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth? School Accountability
Growth and Accountability Student Growth and Value-Added
Future Directions Description, Inference, and Causation
References
A Recurring Metaphor
Data as a window and a mirror
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
Accountability 2.0
Growth and Accountability
Web 2.0 Technologies
Future Directions
References
Accountability 2.0
“This is the difference between a retrospective question of identifying
fault as opposed to a prospective strategy to engineer some corrective
measure, almost independent of considering whether there was
blame-worthiness. And to move away from the blame-worthiness
paradigm toward something that is more regulatory in nature where one
might seize upon disparities or circumstances that are for some reason
deemed unacceptable and engineer the interventions needed to bring
about the necessary change. . . . It’s the no-fault gap closing strategy in
which the effort is to build a consensus about a vision of an improved
society rather than figure out where’s the person we want to pillory.”
C. Edley (2006)
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
Accountability 2.0
Growth and Accountability
Web 2.0 Technologies
Future Directions
References
Accountability 2.0
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].
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
Accountability 2.0
Growth 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/
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
Accountability 2.0
Growth 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
D. W. Betebenner Student Growth Percentiles
The Big Picture
Why Growth?
Growth and Accountability
Future Directions
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. (2012).
Growth, standards, and accountability.
In Cizek, G., editor, Setting Performance Standards: Foundations,
Methods, and Innovations, pages 439–450. Routledge, New York.
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.
Edley, C. (2006).
Educational “Opportunity" is the highest civil rights priority. So what
should researchers and lawyers do about it?
Retrieved June 22, 2006 from the World Wide Web:
http://www.softconference.com/MEDIA/WMP/260407/#43.010.
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.
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.
D. W. Betebenner Student Growth Percentiles
About this copy
Student Growth Percentiles — Renaissance Learning, July 24, 2012.
This is an image-based copy of the original beamer slides; builds and animations are flattened.