The Myths (And Truths) of Teacher Evaluation
Kenneth D Peterson


Myth 1: The central purpose of teacher evaluation is to improve teachers and teaching.  The truth is that there is scarce research to suggest that evaluation causes teacher growth.  Rather, teachers will improve if you give them enough TIME to work on good ideas: uninterrupted time with students, time to plan and implement what is already known, and sufficient discretionary time to be full human beings.  There are other very good reasons to evaluate:  to document current good practice, reassure teachers of a needed and effective job, reassure audiences, identify good teaching practices for emulation, assign teachers for leadership duties (e.g., mentors or student teachers) or special assignment based on effectiveness (e.g., underperforming schools), and prevent bad evaluation practices (of which there are many).


Myth 2:  Improved teacher evaluation is a technical problem. Actually, teacher evaluation is perhaps 85% a sociological/political problem, and 15% a technical challenge.


Myth 3: There is a small number of clearly superior, super-teachers, a large group of adequate, and a substantial number of poor quality teachers. Some teachers stand out when they are (a) very good, and (b) well placed and supported in the right context for the individual. Perhaps upward of 60-70% of teachers perform very well and accomplish much. Researchers place the inadequate teacher at perhaps 5% of the work force.


Myth 4: Teacher quality can be objectively measured and known by using a sufficiently accurate checklist and rating scheme, or by comparing pupil achievement test scores.  Rather, all evaluation is subjective.  However, there is good subjectivity and bad subjectivity.  Good subjectivity is (a) based on the best objective evidence available, (b) controlled for individual bias, (c) involves the interested audiences, and (d) employs some public logic along with expert wisdom.


Myth 5: Better teacher evaluation is just a better rating instrument or framework of teacher behaviors.  The truth is that educators do not agree on what should be included in any single catalog of teacher performances or competencies, none could encompass all of what the open-ended nature of teaching should have, teachers are effective using different sets of small numbers of behaviors, and teachers work in varied contexts which call for different competency sets.  Comprehensive frameworks, descriptions, systems analysis, and lists of duties (e.g., Danielson, 1996; Heath & Nelson, 1974; Scriven, 1988) help build understanding of good teaching, but they don’t cause good evaluation.


Myth 6: Excellent teaching is accomplished by strong performance of 22 (or 27 or 60) components of teaching.  Rather, a good teacher performs three or four components extremely well, adequately performs some others, and (to be accurate) poorly or spottily performs many other things that a teacher is “supposed” to do.  Doing a few things well at the moment carries the entire performances of teaching and learning; the other possible performances simply don’t matter at the given time in the real human world of a classroom.  It is a misleading strategy to try to assess every possible component, duty, competency, or element of a teacher performance at a point in time in order to understand the effective quality of that teaching.


Myth 7The principal is the only and best evaluator.  Rather, others can provide information or opinion, and should be involved.  Peer teachers, administrators, parents, older students, and comparative norms all play a role. Teacher dominated panels of stakeholders are reliable and valid judges of teacher quality.


Myth 8: There are only two well developed lines of evidence of teacher quality: Administrator Report and Value-Added Measurement of Pupil Achievement. Rather, other researched and field tested data sources include: Student reports, Peer Review of instructional materials, National Board Certification, documentation of professional activity, teacher test scores, Parent surveys, Systematic Observation, results of Action Research/School Improvement projects, Payoffs with chronically underserved populations, Clinical supervision improvements, and data Unique to individual Teacher. (Not valid data include: teacher classroom visits/reports, teacher peer rankings, graduate follow ups, microteaching episodes, portfolios).


Myth 9: A uniform system of teacher evaluation is essential: all teachers should be evaluated the same way.  The reality is that teachers are good for different constellations of reasons.  They work in quite different settings, with different kinds of demands and criteria for quality.  Also, we just cannot get all the information we might want for each instance of teacher evaluation. Fairness demands that all teachers have an equal opportunity to document their quality in the ways most appropriate to them. This means use of multiple and variable lines of evidence (data sources).


Myth 10: Pupil achievement data cannot be used in teacher evaluation, OR student learning data can be used for all teachers.  Rather, we can get good pupil achievement data for some but not all teachers in a district; and the teacher evaluation system should reflect the state-of-the-art of data availability. Teachers who can document superior learning gains (adjusted for prior achievement), should be able to be recognized in good teacher evaluation systems.


Myth 11: Higher student achievement test scores at the end of instruction means better teaching (or: educational methods, materials, programs, organizations). Student achievement test scores need to be understood in terms of gain  adjusted for starting performance (prior achievement).


Myth 12: Specific a priori goals (unique to individual or from a general framework) are needed to evaluate a teacher.  Rather, good teaching can be documented after the teaching has been done by highlighting the actual specific outcomes, performances, or preparations that played a role in that specific teacher performance.


Myth 13: Teachers who adhere closest to educational “standards” are the best teachers. No empirical evidence that educational “standards” increase student learning overall. Experts don’t agree on sets of standards; no set of standards encompasses all of its domain. Standards cause teachers to leave their individual strengths, and thus lose some to much effectiveness.


Myth 14Effective Teacher Evaluation has zero costs.  Two constants of the Universe are that Love Hurts and Teacher Evaluation Costs. Too often treated as a no-cost principal duty, Teacher Evaluation has sociological and political costs/benefits. Quality evaluation takes time, personnel, and dollars. (Peterson, 1989).


Myth 15:  Teacher Evaluation and Staff Development are inextricably bound together.  The reality is that these are two important, but independent, programs.


Myth 16: Bad teachers cannot be dismissed.  The reality is that action on unsatisfactory teachers is a principal duty which is widely expected by lay public, parents, teachers, the legal system, and some school districts.  It is difficult (and expensive), and should be, to badly dismiss a deficient teacher or to dismiss a good teacher.  However, principals can effectively team with other district personnel to act on the small number of deficient teachers.


Peterson, K.D., & Peterson, C.A. (2005). Effective teacher evaluation: A guide for principals. Thousand Oaks, CA: Corwin Press.
Peterson, K.D. (2002). Teacher hiring: A guide to getting the best. Alexandria, VA: Association for Supervision and Curriculum Development.
Peterson, K.D. (2000). Teacher evaluation: A comprehensive guide to new directions and practices (2nd ed.).  Thousand Oaks, CA: Corwin Press, Inc.
Peterson, K.D. (1988).  Reliability of panel judgments for promotion in a school teacher career ladder system.  Journal of Research and Development in Education, 21 (4), 95-99.
Peterson, K.D. (1989).  Costs of school teacher evaluation in a career ladder system.  Journal of Research and Development in Education, 22 (2), 30-36.
Peterson, K.D. (1990). Assistance and assessment for beginning teachers. In J. Millman & L. Darling-Hammond (eds.) The new handbook of teacher evaluation: Assessing elementary and secondary school teachers. (pp 104-115). Newbury Park, CA: Sage.