摘要：The study is conducted in the faculty of Education of Jimma University in the first semester of 2004/2005 academic year. It investigated the variability of instructional effectiveness as measured by students' ratings or evaluation. All instructors/lecturers (N = 79) and 2, 370 students were involved in the study. The students were asked to rate their instructors at the end of the semester. Factor analysis, means and standard deviation were employed to analyze the data. The use of factor analysis has succeeded in identifying eight distinct dimensions or units of factor analysis has succeeded in identifying eight distinct dimensions or units of teaching effectiveness: Preparation & organization, Group interaction, Task Responsiveness & Enthusiasm, Professional Ethics, Rapport, Assessment skills, Punctuality, and objectives & Content Clarity. And, there is high level of relative agreement (µ = 0.63 – 0.93) among the different items found to be included under the same dimension or factor of effective teaching. With regard to variability of instructional effectiveness, item 12 (knowledge of the subject matter got the maximum rating (c 4.66) and item 8(accessible to students) received the minimum rating(c = 3.80). The instructors of the faculty are also received the highest rating on the dimension of preparation and organization and lowest rating on their punctuality. At stream level, both language and social sciences are rated the highest at their preparation and organization and lowest in their punctuality; whereas, natural science instructors are evaluated highest in their rapport (dimension five) and receive lowest ratings in their assessment skills. Based on these findings, the following recommendations were forwarded: (1) The summary reports given to instructors should be based on the eight identified factor patterns of the evaluation of the questionnaire. Otherwise, broad global ratings averaged across a collection of heterogeneous items provide little diagnostic feedback and are difficult to interpret. (2) The instructors should improve their availability during consultation hours; they need to have the courage in preparing teaching materials (texts, manuals, etc). (3) Social science departments have to improve themselves with these items: item 11 (welcoming those students seeking help and advice),item 16 (assignments and feedbacks), item 17 (clarified methods of assessment) item 18(inviting idea sharing), and item 26 (appropriate use of instructional materials). Ethiopian Journal of Education and Sciences Vol. 1 (2) 2006: pp. 23-40
