This study compares the effects of object-oriented and robot programming activities on programming achievement, abstraction, problem solving, and motivation. In the study, two consecutive experimental cases were conducted to examine the consistency of findings. The research sample comprises 81 tenth-grade students undergoing vocational secondary education. A total of 41 students participated in the first case that spanned 12 weeks, and 40 students participated in the second that spanned 8 weeks. After computational activities, the programming achievement scores significantly increased in all test groups. However, the achievement scores did not differ significantly between the groups. For the comparison groups, there was no statistically significant difference in the pre- and posttest scores of the formal and descriptive abstraction in both cases. However, a statistically significant increase was found in the formal (only Case 2) and descriptive abstraction scores of the students in the experimental groups. The abstraction results revealed a significant difference in the descriptive abstraction scores of Case 2 in favour of the experimental group. No statistically significant difference was found in the problem-solving scores within or between groups. In both cases, the motivation scores of the experimental groups were found to be statistically higher than those of the comparison groups.