Abstract
This study investigated teachers' instructional design skills, students' perceptions of teachers' instructional design skills, and achievement in mathematics among three senior secondary school 3 students in command secondary schools in Lagos State. The study employed a purposive sampling technique to select three districts and three local government areas that house command secondary schools. A simple random sampling technique was used to select 10 Microsoft Certified Mathematics Educators and an intact class of 100 SS, three students from each school. Thirty mathematics teachers and 300 students were recruited for this study. The Teachers' Instructional Design Skills Observation Rating Scale (r = 0.79), Students' Perception of Teachers' Instructional Design Skills Questionnaire (r =0.82), and the Mathematics Achievement Test (r =0.78) were used for data collection. The data were analyzed using multiple regression at a significance level of p < 0.05. The results revealed a positive association between teachers' instructional design skills, students' perceptions, and students' mathematics achievement (R = 0.25). Additionally, 5.6% of the composite contribution of the variance was observed in student achievement in mathematics, which was statistically significant (F (299) = 9.94). In addition, there was a relatively significant contribution of teachers' instructional design skills (β = 0.23; t = 4.0) and students' perceptions (β = 0.12; t = 2.274) to their mathematics achievement. It was concluded that Microsoft-certified training acquired by teachers enhanced students' mathematics achievement. School authorities in commanded secondary schools should periodically send teachers to train innovative teaching strategies to aid students' assimilation and achievement.