This data set is on testwiseness (TW), learners' autonomy (LA), and students' academic achievement in projectile motion (PMAT). This data set was obtained from Physics students in senior secondary school II (SSS II) in Enugu State of Nigeria. The data also contained a column for students' gender where males are coded as 1 and 2 as females. In the column for age, 1 is for age bracket (12 years below), 2 for (13-16 years), 3 for (17-20 years) and 4 for (21 years above), respectively. This data set is on testwiseness (TW), learners' autonomy (LA), and students' academic achievement in projectile motion (PMAT). This data set was obtained from Physics students in senior secondary school II (SSS II) in Enugu State of Nigeria. The data also contained a column for students' gender where males are coded as 1 and 2 as females. In the column for age, 1 is for age bracket (12 years below), 2 for (13-16 years), 3 for (17-20 years) and 4 for (21 years above), respectively.