This study investigates the influence of visual technological resources on Grade 9 learners’ conceptual knowledge of Transformation Geometry. This was done by giving two groups of learners an opportunity to learn with and without visual technological resources in the form of videos. The conceptual knowledge gains of the learners in both groups were compared and analysed after they wrote the same test. The experimental group was instructed with visual technological resources while the control group was instructed without visual technological resources. The collected data were analysed qualitatively and quantitatively. There were three main items that were analysed i.e., lesson observation schedule data, learners’ actual responses to Transformation Geometry questions and test performance scores of learners. The technological, pedagogical, and content knowledge framework was used in analysing the use of visual technological resources in the classroom by a teacher. The two facets of conceptual knowledge were used to measure the conceptual gains of learners from the written test. It was found that 30 % of the learners in the experimental group performed above 40% in the test that was given to them. 16% of the learners in the control group performed above 40%. An analysis of the learners’ scripts showed that the experimental group had more conceptual gains than those of the control group. The usage of visual technological resources improved the conceptual knowledge of Transformation Geometry for learners in the experimental group.

Keywords: Visual technological resources, conceptual knowledge, transformation geometry.