Abstract:
The purpose of the study was to determine the effect of a developed instructional guide on the performance of students in practical skills in lathe machine operations for teaching and learning practical skills at the National Technical Certificate (NTC) level in Technical Colleges in Northern Nigeria. Six specific purposes and research questions which covered facing, drilling, straight turning, taper turning, knurling, and screw cutting operations were formulated to guide the study. Similarly, six hypotheses were also formulated and tested at 0.05 level of significance. The instrument for data collection was a Practical Exercise Performance Test (PEPT) designed to test students in the major competencies to be acquired in each of the lathe machine operations. The instrument for data collection (PEPT) was subjected to face and content validation by a panel of three vocational educators. To establish the reliability of the practical tests, the test re-test method was adopted. Using the Pearson Product Moment Correlation (PPMC) statistic, the tests yielded 0.69 and 0.71 for first and second tests respectively. Quasi – Experimental group design was adopted for the study. To carry out this, two groups of students located in four schools comprising the treatment and control groups were used for the study over a period of 10 weeks. At the end of the fifth and tenth week, the first and second practical tests were administered at the same time to all the groups. The mean statistic was used to answer the six research questions while the t-test was used to test the hypotheses at 0.05 level of significance. Results showed that students who were taught with the instructional guides perform better than those taught with the conventional lesson plan. This is evident in the mean performance of students taught with the instructional guide in facing operation = 81.21, drilling operation = 83.33, straight turning operation = 80.90, taper turning operation = 77.57, knurling operation = 68.78 and screw cutting operation = 72.42. While students who were taught with conventional lesson plan had mean performance of =52.50 in facing operation, drilling operation =50.83, straight turning operation =58.33, taper turning operation =53.33, knurling operation =49.17 and screw cutting operation =44.44. There was significant difference (P< 0.05) in the mean performance scores of students taught with the instructional guide and those taught with conventional lesson plans in all the lathe machine operations. The findings of the study have implications for the teaching and learning of practical skills in technical colleges in particular and in programmes where skill acquisition is the focus of training in general. The major conclusion of the study is that practical skill acquisition by beginners is enhanced by the use of an instructional guide. It was therefore recommended that the relevant authorities particularly the National Board for Technical Education should include the Practical Skills Instructional Guide as a mandatory instructional material for the teaching of skills in lathe machine operations in technical colleges in the country.
