Teacher supervision has been one of the most researched, though debated, topics in education over the past several decades (Baily, 2009). Conducting a high quality supervision can be of substantial assistance in improving teachers’ instructional performance. This study was conducted to investigate the comparative effects of using three supervision techniques of data gathering including field note, audio-taping and video-taping on instructional performances of teachers and investigate the engaged parties’ (teachers’ and supervisors’) attitudes towards utilizing them in language teacher supervision. To this end, 12 novice teachers with less than one year of teaching experience and two experienced supervisors with 12 years of teaching and supervising experience participated in the study. The teachers were divided into three groups each supervised through one of the aforementioned techniques. The results revealed that video-taping technique of teacher supervision has the most significant effects on teachers’ instructional performance. Besides, teachers and supervisors have positive attitudes towards applying this technique for the data-gathering phase of supervision.
