Teacher Evaluation Reflections

As a PhD candidate working on my dissertation, I have been spending much of my time, searching for information, reading and writing. During the last 2 weeks, I have read almost 100 articles and book chapters about teacher evaluation.  First and foremost, I have developed a much deeper understanding of purposes for teacher evaluation.  There are 2 main purposes:
1) Summative evaluation is to guide decisions regarding employment (hiring, retention, promotion, remediation, etc.)
2) Formative evaluation is to support continuous improvement of teachers' knowledge, skills, and understandings.
Researchers don't necessarily agree whether a teacher evaluation system can be constructed to support both of these purposes simultaneously.

It seems that some policy-makers emphasize summative evaluation because they want to eliminate ineffective teachers.  I wonder if this purpose should be the focus.  Let's think about this in a different context.  Lawmakers are supposed to pass legislation.  If a lawmaker sponsors a bill, but is unsuccessful at getting others to support it, should he or she be eliminated for being ineffective?  Do we consider that there are factors that influence this context which are not under the lawmaker's control?  Could it be that the lawmaker has yet to hone his or her skill set in bill sponsorship and would benefit from guidance from a more seasoned colleague?

The same considerations are appropriate in the education realm.  Teacher knowledge and experience does impact student achievement and growth, but it is not the only factor that does so.  Among these other influential factors are the student's native language, economic level, background experiences, and support network.  A student whose parents can afford to hire a private tutor on a regular basis is more likely to make more growth and attain higher achievement than a student who is living in poverty.

Instead, it would make more sense to focus on formative evaluation.  All teachers can improve their knowledge, skills, and understandings.  A philosophy of continuous improvement supports the growth of teachers in all settings, from the novice to the seasoned veteran.  New policies, strategies and resources continue to emerge for teachers to consider in their daily practice.  Plus, teachers need to readily adapt what they do to meet the unique needs of their students on a daily basis.  I would expect that all stakeholders would benefit from cultivating a climate of continuous improvement as opposed to a culture of fear.

I am also amazed at the multitude of studies that document the fallibility of statistical models, such as Value-Added Models (VAM) and Student Growth Percentiles (SGP).  However, states and school districts use these models to make high-stakes decisions regarding teachers.  If researchers clearly state that VAM and SGP are effective under certain circumstances (such as random assignment of students to classrooms) and the reality is that those circumstances rarely exist, why would policy makers continue to use these models?

Proponents of statistical models have noted that their strength lies in the ability to distinguish effective and ineffective teachers.  However, we're not even sure that the assessments selected in these models are valid for assessing these particular students on the content they were actually taught.  So, how effective are these models for addressing that goal?

Ultimately, what is best for the education profession?  Teacher evaluation that promotes a collaborative culture of supportive learning or teacher evaluation that encourages fear, shame, and withdrawal?