INTRODUCTION 

1.1 Background of the study

Teachers’ quality has been the focus of considerable debated worldwide since the middle of 20th century. Riovkin, Hanushek and Kain (1998), demonstrated in a study that the influence of teachers’ quality on students achievement is many times greater than any other commonly observed variable such as home-background, conducive class environment, etc. Teachers’ quality is a topic with high priority. Teacher qualities differ considerably, between countries and also between states. The National Policy on Education, (Federal  Republic of Nigeria, Revised 2004) while stressing the importance of teacher quality in curriculum implementation noted that no nation’s educational system can rise above the quality of her teachers. Teachers are central to any consideration of schools and majority of educational policy focus directly or indirectly on the role of teachers. Moreover, parents, teachers and administrators emphasize repeatedly the fundamental role that teachers play in comparison to other determinant’s of academic performance. Teachers play in comparison to other determinant’s of academic performance. Teachers are important in any educational system because the quality of teachers in any educational system determines to a great extent the quality of the system itself. For many years, educators and researchers have debated which school variables influence student achievement. As policy makers become more involved in school reform, this question takes on new importance since their initiatives rely on presumed relationship between various educational related factors like class size, teacher quality, school size, etc. Peter (1997), stated that “quality is the basic indispensable feature of a thing”. For example the characteristics of high quality science teachers relates to those attributes that enhances the fitness and efficiency of that teacher in performing the duties that are associated with science education. Teacher quality is an important educational topic among policy makers, educational leaders, teacher education institution and those interested in (improving public education. It is a pivotal   policy issue in education reform and American Council on Education (1999) stated “quality of the teacher is the key to improved student performance regardless of the condition of the schools, the affluence of the child, the nature of the community, or any other element in the lives or educational environment of school children”. Quality teachers are those who use a wide variety of instructional methods, experiences, assignments and materials to ensure that children are achieving a variety of cognitive objectives. Well-prepared highly qualified teachers are essential if we are to ensure that our student achieve the high standards necessary for them to live fulfilling lives and become productive students. Teacher quality was defined by Ingersoll (1996) as a measure of teacher qualification, teaching practices, teacher certification, teacher experience and teaching preparations. Teacher qualification includes such components as content knowledge pedagogical knowledge, teaching credentials and verbal abilities. Shulman (1987) identified seven (7) areas of professional for quality teaching which are academic subject, knowledge of teaching strategies, knowledge of student’s characteristics and cultural background, knowledge of curriculum materials and programs, knowledge of teaching environment, subject specific knowledge of teaching strategies and knowledge of the goals and purposes of teaching. Salvin (2003) emphasized that a good quality teacher must know his/her subject matter very well and how to motivate children. He must also know how to use class time effectively, and how to respond to individual differences. Teachers have been known to have important influence on students’ academic achievement and they also play a crucial role in educational attainment because the teacher is ultimately responsible for translating educational policies and principles into actions based on practice during interaction with the students (Afe, 2001). Both teaching and learning depend on teachers: no wonder an effective teacher has been conceptualized as one who produces desired results in the course of his duty as a teacher (Uchefuna 2001). Considering governments’ huge investment in public education, its output in terms of quality of students has been observed to be unequal with government expenditure. Consequent upon the observed deterioration in the academic achievement, attitude and values of secondary school students in public secondary schools, one wonders if the high failure rates and the failure of the students especially in external examinations is not a reflection of the instructional quality in the schools. Therefore, the ineffectiveness of teachers in classroom interaction with the students could be responsible for the observed poor performance of students and the widely acclaimed fallen standard of education in Nigeria. 

1.2 STATEMENT OF THE PROBLEM

According to what I have heard and experienced, there is critical shortage of qualified teachers throughout the country. This has forced many states to employ people who do not meet the requirement of a qualified teacher, that is, they have not demonstrated subject matter competence. They do not have formal training as teachers and many do not have prior experience of teaching. Many secondary schools have significantly higher teacher vacancy rate but teacher transfers out to other profession in greater numbers. In my senior secondary school three (SS3), I had a physics teachers who just graduated from university as a chemical engineer two( 2) years before he was employed in my school. According to the physics teacher, this was his first time of teaching. The physics teacher from my observation as a student did not have a good knowledge of subject matter and his method of teaching was good enough. This reflected on the performance of the senior secondary three (SS3) students in physics when their WAEC (West African Examination Council) result was out. The performance was poor. On this background the researcher wants to investigate the impact of teacher’s quality on the academic performance of secondary school students