Posted: June 13th, 2021
8 Kappan March 2012
LINDA DARLING-HAMMOND ([email protected]) is the Charles Ducommun professor of teaching and teacher education, Stan-
ford University, Stanford, Calif. AUDREY AMREIN-BEARDSLEY is an associate professor of education, Arizona State University,
Phoenix, Ariz. EDWARD HAERTEL is the Jacks Family professor of education, Stanford University, Stanford, Calif. JESSE ROTH-
STEIN is an associate professor of economics and public policy, University of California, Berkeley.
ractitioners, researchers, and policy makers agree that most current teacher evaluation sys-
tems do little to help teachers improve or to support personnel decision making. There’s also
a growing consensus that evidence of teacher contributions to student learning should be
part of teacher evaluation systems, along with evidence about the quality of teacher practices.
“Value-added models” (VAMs), designed to evaluate student test score gains from one year to
the next, are often promoted as tools to accomplish this goal.
Value-added models enable researchers to use statistical methods to measure changes in student scores
over time while considering student characteristics and other factors often found to influence achievement.
In large-scale studies, these methods have proved valuable for looking at factors affecting achievement and
measuring the effects of programs or interventions.
Using VAMs for individual teacher evaluation is based on the belief that measured achievement
gains for a specific teacher’s students reflect that teacher’s “effectiveness.” This attribution, however,
assumes that student learning is measured well by a given test, is influenced by the teacher alone, and is
independent from the growth of classmates and other aspects of the classroom context. None of these
assumptions is well supported by current evidence.
Most importantly, research reveals that gains in student achievement are influenced by much more than
any individual teacher. Others factors include:
• School factors such as class sizes, curriculum materials, instructional time, availability of specialists and
tutors, and resources for learning (books, computers, science labs, and more);
• Home and community supports or challenges;
• Individual student needs and abilities, health, and attendance;
• Peer culture and achievement;
• Prior teachers and schooling, as well as other current teachers;
• Differential summer learning loss, which especially affects low-income children; and
• The specific tests used, which emphasize some kinds of learning and not others and which rarely
measure achievement that is well above or below grade level.
However, value-added models don’t actually measure most of these factors. VAMs rely on statistical
controls for past achievement to parse out the small portion of student gains that is due to other factors,
Popular modes of evaluating teachers are fraught with inaccuracies
and inconsistencies, but the field has identified better approaches.
By Linda Darling-Hammond, Audrey Amrein-Beardsley,
Edward Haertel, and Jesse Rothstein
V93 N6 kappanmagazine.org 9 Thinkstock/iStockphoto
Kappan at www.
of which the teacher is only one. As a consequence,
researchers have documented a number of problems
with VAM models as accurate measures of teachers’
1. Value-added models of teacher effectiveness are
Researchers have found that teacher effectiveness
ratings differ substantially from class to class and
from year to year, as well as from one statistical model
to the next, as Table 1 shows.
A study examining data from fi ve school districts
found, for example, that of teachers who scored in
the bottom 20% of rankings in one year, only 20%
to 30% had similar ratings the next year, while 25%
to 45% of these teachers moved to the top part of
the distribution, scoring well above average. (See
Figure 1.) The same was true for those who scored
at the top of the distribution in one year: A small
minority stayed in the same rating band the follow-
ing year, while most scores moved to other parts of
Teacher effectiveness also varies signifi cantly
when different statistical methods are used (Briggs
& Domingue, 2011; Newton et al., 2010; Rothstein,
2007). For example, when researchers used a differ-
ent model to recalculate the value-added scores for
teachers published in the Los Angeles Times in 2011,
they found that from 40% to 55% of them would
get noticeably different scores (Briggs & Domingue,
Teachers’ value-added scores also differ signifi –
cantly when different tests are used, even when these
are within the same content area (Bill & Melinda
Gates Foundation, 2010; Lockwood et al., 2007).
This raises concerns both about measurement er-
Percent of teachers whose effectiveness rankings change
Across models a
Across courses b
Across years b
Note: a Depending on pair of models compared. b Depending on the model used.
Source: Newton, Darling-Hammond, Haertel, & Thomas (2010).
BY 1 OR MORE DECILES
BY 2 OR MORE DECILES
BY 3 OR MORE DECILES
ror and, when teacher evaluation results are tied
to student test scores, the effects of emphasiz-
ing “teaching to the test” at the expense of other
kinds of learning, especially given the narrowness
of most tests in the United States.
2. Teachers’ value-added performance is affected
by the students assigned to them.
VAMs are designed to identify teachers’ effects
Teachers’ value-added scores differ
signifi cantly when different tests are used,
even when these are within the same
10 Kappan March 2012
when students are assigned to teachers randomly.
However, students aren’t randomly assigned to
teachers — and statistical models can’t fully adjust
for the fact that some teachers will have a dispropor-
tionate number of students who have greater chal-
lenges (e.g., students with poor attendance, who are
homeless, who have severe problems at home, etc.)
and those whose scores on traditional tests may
not accurately reflect their learning (e.g., those who
have special education needs or who are new English
Even when the model includes controls for prior
achievement and student demographic variables,
teachers are advantaged or disadvantaged based on
the students they teach. Several studies have shown
this by conducting tests that look at teacher “ef-
fects” on students’ prior test scores. Logically, for
example, 5th-grade teachers can’t influence their
students’ 3rd-grade test scores. So a VAM that iden-
tifies teachers’ true effects should show no effect of
5th-grade teachers on students’ 3rd-grade test scores
two years earlier. But studies that have looked at this
have shown large “effects” — which indicates that
the VAMs wrongly attribute to teachers other influ-
ences on student performance that are present when
the teachers have no contact with the students (Roth-
One study that found considerable instability in
teachers’ value-added scores from class to class and
year to year examined changes in student charac-
teristics associated with changes in teacher ratings.
After controlling for prior student test scores and stu-
dent characteristics, the study still found significant
correlations between teacher ratings and students’
race/ethnicity, income, language background, and
parent education. Figure 2 illustrates this finding for
an experienced English teacher whose rating went
from the very lowest category in one year to the very
highest category the next year (a jump from the 1st
to the 10th decile). In the second year, this teacher
had many fewer English learners, Hispanic students,
and low-income students, and more students with
well-educated parents than in the first year.
This variability raises concerns that using such
ratings for evaluating teachers could create disin-
centives for teachers to serve high-need students.
3. Value-added ratings can’t disentangle the many
influences on student progress.
Given all of the other factors operating, it appears
Changes in VA scores from 2001 to 2002 for low-ranking teachers
Move to above
Move up in
Stay in bottom
San Diego Duval Co., Hillsborough Co., Orange Co., Palm Beach Co.,
Calif. Fla. Fla. Fla. Fla.
Source: Sass, T. (2008).
Teachers are advantaged or disadvantaged
based on the students they teach.
V93 N6 kappanmagazine.org 11
Houston as a result of its Education Value-Added
Assessment System (EVAAS) scores was a 10-year
veteran who had been voted Teacher of the Month
and Teacher of the Year and was rated each year as
“exceeding expectations” by her supervisor (Amrein-
Beardsley & Collins, in press). She showed positive
VA scores on 8 of 16 tests over four years (50% of
the total observations), with wide fluctuations from
year to year, both across and within subjects. (See
Table 2.) It is worth noting that this teacher’s lower
value-added in 4th grade, when English learners
are mainstreamed in Houston, was also a pattern
for many other teachers.
The wide variability shown in this teacher’s rat-
ings from year to year, like that documented in many
other studies, wasn’t unusual for Houston teachers
in this analysis, regardless of whether the teacher
was terminated. Teachers said they couldn’t identify
a relationship between their instructional practices
and their value-added ratings, which appear unpre-
dictable. As one teacher noted:
I do what I do every year. I teach the way I teach
every year. [My] first year got me pats on the back;
[my] second year got me kicked in the backside. And
for year three, my scores were off the charts. I got a
huge bonus, and now I am in the top quartile of all
the English teachers. What did I do differently? I
have no clue (Amrein-Beardsley & Collins, in press).
that “teacher effectiveness” is not a stable enough
construct to be uniquely identified even under ideal
conditions (for example, with random assignment
of teachers to schools and students to teachers, and
with some means of controlling differences in out-
of-school effects). Furthermore, some teachers may
be effective at some forms of instruction or in some
portions of the curriculum and less effective in oth-
ers. If so, their rated effectiveness would depend on
whether the student tests used for the VAM empha-
size skills and topics for which the teacher is relatively
more or relatively less effective.
Other research indicates that teachers whose
students do best on end-of-year tests aren’t always
effective at promoting longer-run achievement for
their students. Thus, VAM-style measures may be
influenced by how much the teacher emphasizes
short-run test preparation. One study even found
that teachers who raised end-of-course grades most
were, on average, less effective than others at prepar-
ing students for next year’s course (Carrell & West,
Initial research on using value-added methods to
dismiss some teachers and award bonuses to oth-
ers shows that value-added ratings often don’t agree
with ratings from skilled observers and are influ-
enced by all of the factors described above.
For example, one of the teachers dismissed in
this article with
activities in this
by Lois Brown
a PDF of the
guide at kappan
Student characteristics in years 1 and 2 for a teacher whose ranking changed
from the 1st to the 10th decile
% % % Parent
ELL Low-income Hispanic education
12 Kappan March 2012
• Ratings change considerably when teachers
change grade levels, often from “ineffective” to
“effective” and vice versa.
These kinds of comments from teachers were
Every year, I have the highest test scores, [and] I have
fellow teachers that come up to me when they get
their bonuses . . . One recently came up to me [and]
literally cried, ‘I’m so sorry.’ . . . I’m like, ‘Don’t be
sorry. It’s not your fault.’ Here I am . . . with the
highest test scores, and I’m getting $0 in bonuses.
It makes no sense year to year how this works. You
know, I don’t know what to do. I don’t know how to
get higher than 100%.
I went to a transition classroom, and now there’s a red
flag next to my name. I guess now I’m an ineffective
teacher? I keep getting letters from the district, saying
‘You’ve been recognized as an outstanding teacher’ . . .
this, this, and that. But now because I teach English
language learners who ‘transition in,’ my scores drop?
And I get a flag next to my name for not teaching
them well? (Amrein-Beardsley & Collins, in press).
A study of Tennessee teachers who volunteered to
be evaluated based on VAMs and to have a substan-
tial share of their compensation tied to their VAM
results, corroborated this evidence: After three years,
85% thought the VAM evaluation ignored impor-
tant aspects of their performance that test scores
didn’t measure, and two-thirds thought VAM didn’t
do a good job of distinguishing effective from inef-
fective teachers (Springer et al., 2010).
For all of these reasons and more, most research-
ers have concluded that value-added modeling is not
appropriate as a primary measure for evaluating in-
dividual teachers. (See, for example, Braun, 2005;
National Research Council, 2009.)
While value-added models based on test scores
Another teacher classified her past three years as
“bonus, bonus, disaster.” And another noted:
We had an 8th-grade teacher, a very good teacher,
the “real science guy”. . . [but] every year he showed
low EVAAS growth. My principal flipped him with
the 6th-grade science teacher who was getting the
highest EVAAS scores on campus. Huge EVAAS
scores. [And] now the 6th-grade teacher [is showing]
no growth, but the 8th-grade teacher who was sent
down is getting the biggest bonuses on campus.
This example of two teachers whose value-added
ratings flip-flopped when they exchanged assign-
ments is an example of a phenomenon found in other
studies that document a larger association between
the class taught and value-added ratings than the
individual teacher effect itself. The notion that there
is a stable “teacher effect” that’s a function of the
teacher’s teaching ability or effectiveness is called
into question if the specific class or grade-level as-
signment is a stronger predictor of the value-added
rating than the teacher.
Another Houston teacher whose supervisor con-
sistently rated her as “exceeding expectations” or
“proficient” and who also was receiving positive VA
scores about 50% of the time, had a noticeable drop
in her value-added ratings when a large number of
English language learners transitioned into her class-
room. Overall, the study found that, in this system:
• Teachers of grades in which English language
learners (ELLs) are transitioned into
mainstreamed classrooms are the least likely to
show “added value.”
• Teachers of large numbers of special education
students in mainstreamed classrooms are also found
to have lower “value-added” scores, on average.
• Teachers of gifted students show little value-
added because their students are already near
the top of the test score range.
2006-2010 EVAAS scores of a teacher dismissed as a result of these scores
Notes: * The scores with asterisks (*) signify that the scores are not detectably different from the reference gain scores of other
teachers across Houston Independent School District within one standard error; however, the scores are still reported to both
the teachers and their supervisors as they are here.
V93 N6 kappanmagazine.org 13
ground evaluation in student learning in more stable
ways. Typically, performance assessments ask teach-
ers to document their plans and teaching for a unit
of instruction linked to state standards, adapt them
for special education students and English language
learners, videotape and critique lessons, and collect
and evaluate evidence of student learning.
Professional standards have also been translated
into teacher evaluation instruments at the local level.
Cincinnati Public Schools uses an unusually care-
ful standards-based system for teacher evaluation
that involves multiple classroom observations and
detailed written feedback to teachers. This system,
like several others in local districts, has been found
both to produce ratings that reflect teachers’ effec-
tiveness in supporting student learning gains and to
improve teachers’ performance and their future ef-
fectiveness (Milanowski, Kimball & White, 2004;
Milanowski, 2004; Rockoff & Speroni, 2010; Taylor
& Tyler, 2011.)
A Bill & Melinda Gates Foundation initiative is
identifying additional tools based on professional
standards and validated against student achievement
gains to be used in teacher evaluation at the local
level. The Measures of Effective Teaching (MET)
Project has developed a number of tools, includ-
ing observations or videotapes of teachers, supple-
mented with other artifacts of practice (lesson plans,
assignments, etc.), that can be scored according to
standards that reflect practices associated with ef-
Building better systems
Systems that help teachers improve and that sup-
port timely and efficient personnel decisions have
more than good instruments. Successful systems use
multiple classroom observations across the year by
expert evaluators looking at multiple sources of data,
and they provide timely and meaningful feedback to
For example, schools using the Teacher Advance-
ment Program, which is based on NBPTS and IN-
TASC standards as well as the standards-based as-
sessment rubrics developed in Connecticut (Bill &
Melinda Gates Foundation, 2010; Rothstein, 2011),
are problematic for making evaluation decisions for
individual teachers, they are useful for looking at
groups of teachers for research purposes — for ex-
ample, to examine how specific teaching practices or
measures of teaching influence the learning of large
numbers of students. Such analyses provide other in-
sights for teacher evaluation because we have a large
body of evidence over many decades concerning how
specific teaching practices influence student learning
gains. For example, we know that effective teachers:
• Understand subject matter deeply and flexibly;
• Connect what is to be learned to students’ prior
knowledge and experience;
• Create effective scaffolds and supports for
• Use instructional strategies that help students
draw connections, apply what they’re learning,
practice new skills, and monitor their own
• Assess student learning continuously and adapt
teaching to student needs;
• Provide clear standards, constant feedback, and
opportunities for revising work; and
• Develop and effectively manage a collab-
orative classroom in which all students have
membership (Darling-Hammond & Bransford,
These aspects of effective teaching, supported by
research, have been incorporated into professional
standards for teaching that offer some useful ap-
proaches to teacher evaluation.
Using professional standards
The National Board for Professional Teaching
Standards (NBPTS) defined accomplished teach-
ing to guide assessments for veteran teachers. Sub-
sequently, a group of states working together under
the auspices of the Council for Chief State School
Officers created the Interstate New Teacher Assess-
ment and Support Consortium (INTASC), which
translated these into standards for beginning teach-
ers that have been adopted by over 40 states for initial
teacher licensing. Revised INTASC teaching stan-
dards have been aligned with the Common Core
Standards to reflect the knowledge, skills, and under-
standings that teachers need to enact the standards.
These standards have become the basis for as-
sessments of teaching that produce ratings that are
much more stable than value-added measures. At
the same time, these standards incorporate class-
room evidence of student learning, and large-scale
studies have shown that they can predict teachers’
value-added effectiveness (National Research Coun-
cil, 2008; Wilson et al., 2011), so they have helped
The notion that there is a stable “teacher
effect” that’s a function of the teacher’s
teaching ability or effectiveness is called
into question if the specific class or grade-
level assignment is a stronger predictor of
the value-added rating than the teacher.
14 Kappan March 2012
surable outcomes in hard-to-quantify areas like art,
music, and physical education; and to monitor stu-
dent learning growth. They also showed a greater
awareness of the importance of sound curriculum
development, more alignment of curriculum with
district objectives, and increased focus on higher-
quality content, skills, and instructional strategies
(Packard & Dereshiwsky, 1991).
Some U.S. districts, along with high-achieving
countries like Singapore, emphasize teacher col-
laboration in their evaluation systems. This kind of
measure is supported by studies finding that students
have stronger achievement gains when teachers work
together in teams (Jackson & Bruegmann, 2009) and
when there is greater teacher collaboration for school
improvement (Goddard & Goddard, 2007).
New approaches to teacher evaluation should
take advantage of research on teacher effectiveness.
While there are considerable challenges in using
value-added test scores to evaluate individual teach-
ers directly, using value-added methods in research
can help validate measures that are productive for
Research indicates that value-added measures
of student achievement tied to individual teachers
should not be used for high-stakes, individual-level
decisions, or comparisons across highly dissimilar
schools or student populations. Valid interpretations
require aggregate-level data and should ensure that
background factors — including overall classroom
composition — are as similar as possible across
groups being compared. In general, such measures
should be used only in a low-stakes fashion when
they’re part of an integrated analysis of teachers’
Standards-based evaluation processes have also
been found to be predictive of student learning gains
and productive for teacher learning. These include
systems like National Board certification and per-
formance assessments for beginning teacher licens-
ing as well as district and school-level instruments
based on professional teaching standards. Effective
systems have developed an integrated set of mea-
sures that show what teachers do and what happens
as a result. These measures may include evidence
of student work and learning, as well as evidence of
teacher practices derived from observations, video-
tapes, artifacts, and even student surveys.
These tools are most effective when embedded in
systems that support evaluation expertise and well-
grounded decisions, by ensuring that evaluators are
trained, evaluation and feedback are frequent, men-
toring and professional development are available,
and processes are in place to support due process
evaluate teachers four to six times a year using mas-
ter/mentor teachers or principals certified in a rigor-
ous four-day training. The indicators of good teach-
ing are practices found to be associated with desired
student outcomes. Teachers also study the rubric
and its implications for teaching and learning, look
at and evaluate videotaped teaching episodes using
the rubric, and engage in practice evaluations. After
each observation, the evaluator and teacher discuss
the findings and plan for ongoing growth. Schools
provide professional development, mentoring, and
classroom support to help teachers meet these stan-
dards. TAP teachers say this system, along with the
intensive professional development offered, is sub-
stantially responsible for improving their practice
and for student achievement gains in many TAP
schools (Solomon, White, Cohen, & Woo, 2007).
In districts that use Peer Assistance and Review
(PAR) programs, highly expert mentor teachers sup-
port novice teachers and veteran teachers who are
struggling, and they conduct some aspects of the
evaluation. Key features of these systems include
not only the evaluation instruments but also the ex-
pertise of the consulting teachers or mentors, and a
system of due process and review in which a panel of
teachers and administrators make recommendations
about personnel decisions based on evidence from
the evaluations. Many systems using this approach
have improved teaching while they have also become
more effective in identifying teachers for continua-
tion and tenure as well as intensive assistance and,
where needed, dismissal (NCTAF, 1996; Van Lier,
Some systems ask teachers to assemble evidence
of student learning as part of the overall judgment
of effectiveness. Such evidence is drawn from class-
room and school-level assessments and documenta-
tion, including pre- and post-test measures of stu-
dent learning in specific courses or curriculum areas,
and evidence of student accomplishments in relation
to teaching activities. A study of Arizona’s career lad-
der program, which requires teachers to use vari-
ous methods of student assessment to complement
evaluations of teacher practice, found that, over time,
participating teachers improved their ability to cre-
ate tools to assess student learning gains; to develop
and evaluate before and after tests; to define mea-
Successful systems use multiple
classroom observations, expert evaluators,
multiple sources of data, are timely,
and provide meaningful feedback to the
V93 N6 kappanmagazine.org 15
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