Abstract

There are web-based tools which are readily available to develop online instruments to diagnose students’ understanding of chemistry topics. Multiple-tier multiple choice diagnostic instruments are easily developed using tools such as Google Forms, as well as easily administered to students. In general, results are automatically collated by these tools and can be downloaded as MS Excel files for further analysis. This paper describes the development of a web-based diagnostic tool on ionisation energy based on a pen-and-paper version developed in a previous study, and the affordances of the web-based version over the pen-and-paper version. The web-based version allows specific sets of second-tier options to be offered to students based on the first-tier answers chosen and the option to choose more than one second-tier reason or for students to supply their own reason(s). The results from the administration of the web-based instrument indicated that all student difficulties determined by the pen-and-paper version in the previous study also surfaced in the students’ responses to the items in the web-based instrument; in fact, more instances of similar student difficulties were determined, in addition to new ones. Direct evidence of students’ possible manifold conceptions was also obtained. Thus, this paper makes a strong argument for the use of such web-based tools in the formative assessment of students’ understanding of chemistry concepts.