ver the past two decades, there has been very little research directly examining the relationship between educational level and job performance. This, as noted by Benson, Fine gold and Mohrman (2004), is particularly surprising given the fact that it was during this time period when educational opportunities increased substantially and when most organizations raised their educational qualifications for jobs. It was also during this period too, that most state governments begun to emphasize the need for all primary and postprimary institutions to have only professionals in education as teachers. In Cross River State, for instance, government has since the year 2001 implemented the on a minimum qualification of NCE for teachers in primary schools and First Degree for teachers in Secondary schools. In furtherance of this policy, it does appear that most state governments in Nigeria are beginning to emphasize that all teachers must have educational qualifications to enhance their productivity. This is in line with the opinions of some authorities who have conducted researches in education.

Breman (2001), for instance, asserted that if any nation is to live up to societal expectation of producing highly skilled labour and research oriented individuals to meet with present day economic and scientific challenges, then the job performance of its teachers must be viewed with special interest. In the classroom, teachers' job performance is crucial in students' progress and development. The progress of students is directly linked to the successful teaching learning process in the classroom. Teachers job performance relate to what teachers do in the classroom and how that affects students learning.

Thomas and Feldman (2009) compared education level with job performance and discovered a positive relationship between education level and different job behaviours in task and citizenship, and negatively related to counterproductive performance like on-the-job substance use and absenteeism. Gede and Anike (2011) in a similarly study on staff of the Bayelsa State Ministry of Education discovered that the higher the qualification of the staff of secondary schools the better their job performance. The study reports an adverse effect of poor staffing on job performance and recommend among other things, recruitment of qualified teachers.

Students' academic performance or achievement is an important index for the measurement of teachers' job performance. Any teacher whose students come out at the end of an instruction with good grades in the school subject(s) taught can be adjudged as having performed very well in his job. It has, however, been discovered that there has been differential academic achievement of students in Nigeria (Unanma, Abugu, Dike and Umeobiko; 2013), and this has been and is still a source of concern and research interest to educators, government and parents. Many researche works have been carried out to examine the phenomenon and to discover the factors that may be responsible for the ugly trend. A few of these researchers have identified teachers' academic disciplines as having some influence on students' academic performance. Unanma et al (2013) examined the relationship between teachers' educational qualification and their students' performance in chemistry. The result of the study revealed a positive relationship between teachers' qualifications and students' academic achievement. The study concluded that the higher the professional qualification of the teachers, the better the achievement of their students. In an earlier study carried out by Gede and Lawson (2011) using 50 employees out of 221 on the staff, it was discovered that teachers' professional qualifications influence their job performance.

The design adopted in this study was survey. This design was chosen because of the largeness of the sample size and the fact that the team used questionnaires in collecting data required for the study. A sample of 1062 teachers was selected from a population of about 21,240 teachers in state public schools. At the time of this research, the state ministry of education was concluding recruitment of teachers, so it was difficult to be exact on the number of teachers on the roll. By this selection, however, the study adopted about 5% of the population as sample. The sampling techniques used for selecting the sample were stratified random and purposive sampling techniques with the different Local Government Education Authorities as the basis of stratification. Each of the 18 education authorities was considered as a stratum. Five per cent of the number of schools in each education authority was selected for the study. After the selection of schools, the researchers selected the teachers purposely from the schools, at convenience, to meet the 5% target.

The study area was Cross River State of Nigeria. The state is made up of 18 education authorities (one each in each local government, area). The area is made up of 203 public secondary schools with Calabar education authority having the highest number of schools.

An instrument called teachers' performance rating scale (TPRS) was used for data collection. This rating scale was administered to students to gather data on the job performance of teachers. Four dimensions of teachers' job performance, namely, lesson delivery, assessment/evaluation, classroom management, and student discipline, were measured in the scale using eight items each. The instrument was face validated by the research team and trail tested for internal consistency using Cronbach Alpha reliability estimate method. The reliability coefficients ranged from 0.71 to 0.86 for the sub-scales.

The hypothesis tested stated that teachers job performance does not differ significantly based on their academic disciplines. Results of analysis in Table 2 shows that the calculated F-ratios for lesson delivery (110.139), students' assessment/evaluation (53.379), classroom management (147.082), students' discipline (139.163), and for overall job performance (198.845) are each greater than the critical F-ratio of 3.00 at 0.5 level of significance, using 2 and 1059 degrees of freedom. This means that at all dimensions of consideration, teachers' job performance differ significantly based on their academic discipline. Based on these results the null hypothesis was rejected.

Since the results show significant influence of academic discipline on teachers' job performance, a post-hoc test was carried out to determine the pair-wise mean difference(s) among the groups that, was or were responsible for the influence. The method of post-hoc analysis used was fisher's least significant difference (LSD). Results of the analysis are presented in table 3.

Results of post-hoc analysis were as follows for the different sub-variables of teachers' job performance:

The results show that teachers with PGDE (X=89.34) were the best in overall job performance, followed by those with B.Ed (X=72.20) and then by others with B.A/B.Sc degrees (X=69.85).

Results of the study showed that teachers' job performance significantly differ based on their academic disciplines. The results show that at all dimension of teachers' job performance it was teachers who have PGDE degree or its equivalent as their qualification that perform better in lesson delivery, student assessment/evaluation, classroom management and student discipline than their counterparts with B.Ed degree or its equivalent and those with B.A/B.Sc or its equivalent. Results on overall job performance also show a significant difference based on academic disciplines with holders of PGDE out performing holders of other degrees, followed by holders of B.Ed degrees and then by holders of other degrees. The findings replicate that of Thomas and Feldman (2009) who compared education level with job performance and discovered a positive relationship between education level and different job behaviours in task and citizenship. The same study found a negative relationship between education level and counterproductive performance like on-the-job substance use and absenteeism. The result also replicated the findings of Gede and Anike (2001) and Ubanma et al (2013) who independently found that professional qualification influenced job performance.

The implication of this finding and the replications hinges on the issue of paper qualification which has been of concern to many people in different works of life. A good number of people in Nigeria feel that the country has placed too much emphasis on paper qualification instead on the productivity of would be employees. Some go the extent of feeling that a good number of people who never went to school may actually do better on the job than those with certificates of school attendance. The result of this study has proven this assession wrong. The findings show clearly that the higher the qualifications of teachers the better their performance. The results also show that the more professionally qualified a person the more likely his ability to perform professional tasks. The study therefore recommends that educational institutions especially primary and secondary schools should encourage professionalism. Schools should discourage the current trend in which teachers are made to teach subjects they did not study at the university even when the subjects seem related to what they actually studied. Government should find a way of ensuring that only teachers with education degrees are allowed to teach in our primary and secondary schools.

Results of the study showed that teachers' job performance significantly differ based on their academic disciplines. The results show that at all dimension of teachers' job performance it was teachers who have PGDE degree or its equivalent as their qualification that perform better in lesson delivery, student assessment/evaluation, classroom management and student discipline than their counterparts with B.Ed degree or its equivalent and those with B.A/B.Sc or its equivalent. Results on overall job performance also show a significant difference based on academic disciplines with holders of PGDE out performing holders of other degrees, followed by holders of B. The implication of this finding and the replications findings on the issue of paper qualification which has been of concern to many people in different works of life. A good number of people in Nigeria feel that the country has placed too much emphasis on paper qualification instead on the productivity of would be employees. Some go the extent of feeling that a good number of people who never went to school may actually do better on the job than those with certificates of school attendance. The result of this study has proven this assession wrong. The findings show clearly that the higher the qualifications of teachers the better their performance. The results also show that the more professionally qualified a person the more likely his ability to perform professional tasks. The study therefore recommends that educational institutions especially primary and secondary schools should encourage professionalism. Schools should discourage the current trend in which teachers are made to teach subjects they did not study at the university even when the subjects seem related to what they actually studied. Government should find a way of ensuring that only teachers with education degrees are allowed to teach in our primary and secondary schools.