Teaching of chemistry at secondary school level is not always carried out in the most effective way and this is often because teachers do not realise the difficulties experienced by pupils while studying a conceptually challenging topic. The development of a teaching strategy to assist teachers is thus of value. The research questions:  Do focussed intervention questions followed by rapid feedback to pupils foster sound concept formation in chemical bonding?  Is this new teaching method more effective than traditional methods? In this study I have examined the effect of a novel teaching method (referred to as the Targeted Intervention Questioning process) on concept formation during the study of chemical bonding. This study involves action research in secondary school classrooms. The findings from the study are being used to further inform current teaching practice. The teaching method is a set of focused intervention questions administered at relevant stages during the teaching of the topic. Pupils answer these questions with the help of their learning material and are given rapid feedback with an evaluation of their answers. This questioning process is designed to focus pupils’ attention on the relevant concepts and the feedback is to inform pupils of their progress in mastering the topic. The effectiveness of the method was measured using a concept development test. The learning gain in a test group was compared to that of a control group in a quasi-experimental study. This research involves action research as findings will inform practice and practice will change in line with the research findings. Data gathering to ascertain the effectiveness of the teaching method will be through quantitative methods in a quasi-experimental setup. The sample size was approximately 80 learners, divided into the four classes. All teachers use the methods and techniques that they normally use. The learning gain was determined through the use of a concept development test developed by the author (referred to as the Conceptual Test tool). This test tool contained a set of 25 conceptual questions, either requiring selection of a correct answer from a multiple choice selection or requiring a free response answer. The testing tool was piloted using a group of Grade 11 pupils in 2010. The test was then refined and used to measure the effectiveness of the intervention questioning process in 2011. A second run of the intervention process was carried out in 2012 using a slightly modified testing tool. The result of the test group was compared to that of the control group. A Correlation analysis and a Rasch analysis determined the validity of the testing tool. Results from both runs of the intervention process show that the test group has a statistically significant greater learning gain (LG) over the control group. Analysis of answers given by pupils to the intervention questions provided insight into the learning process that was happening. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Science, Mathematics and Technology Education / unrestricted