Teachers often dread formal observations. The results are filed away permanently in the teacher's human resource file, and decisions such as tenure and promotions can be based on this information. While teacher observations have distinct advantages, the disadvantages are quite striking. To best evaluate a teacher, districts should use observation in conjunction with other sources of data.

Advantage: Obtain Additional Information

Teacher observations provide information that other means of evaluation do not. For example, the evaluator can observe the interactions between the teacher and his students to determine whether the teacher has established rapport, treats students with respect and addresses questions effectively. Observation also offers the opportunity to see whether the teacher uses effective teaching methods, has control over his class and is able to address the needs of all learners. To be most effective, teacher observations should not be announced in advance, lest the evaluator observe an inauthentic environment, known in the profession as a "dog and pony show."

Advantage: Can Provide Instant Feedback

Teacher observations are ideally used for formative as well as evaluative purposes. When a skilled evaluator observes a teacher in action, she can provide feedback to the teacher about his performance the same day. This can yield faster improvements and adjustments to teaching style. Teachers with ineffective practices can begin to implement needed changes immediately based on the evaluator's critique. Follow-up observations and evaluations can be scheduled until they are on the right track.

Disadvantage: Bias

All workplaces have some degree of bias, and schools are no exception. Whether the evaluations are conducted by peers or administrators, bias has the potential to invalidate the results. An evaluator may impose his own beliefs about teaching on the teacher being observed. He may not personally like the teacher or may have unconscious biases related to the teacher's age, gender or ethnic or economic background. If an evaluator is friends with the teacher, this may be reflected in the evaluation as well.

Disadvantage: Unreliable

A teacher spends approximately six hours a day, 180 days a year teaching. The observational method of teacher evaluation makes the assumption that the evaluator will get an accurate picture of the teacher's effectiveness in the classroom by observing the teacher during one hour or two hours of this time. Many teachers become nervous when being observed, and their performance may suffer. If the evaluator is an administrator, student behavior may also change, as they will not want to suffer the consequences of misbehaving in front of that individual. The result of these observations can often be distorted data.