USING ONLINE THREE-TIER DIAGNOSTIC TEST TO ASSESS CONCEPTIONS OF IONIZATION ENERGY

The term describing the students’ notions of scientific concepts dissimilar from scientifically acceptable by the scientist is still debated. This study explores of how scientific concepts performed by high school students (HSSs), pre-service teachers (PSTs), and in-service teachers (ISTs) simultaneously to make clear between their conception vs. scientists’ conception, especially in the ionization energy concept. Therefore, it is crucial to raise the position of scientific conception and misconception. For diagnosing the misconceptions, some methods can be used: concept maps, interviews, multiple-choice tests (one-tier), multiple-tier tests (two-tier, three-tier, fourtiers), open-ended tests, and others. This study utilized multiple-tier tests with three-tier. Totally, 326 participants from Indonesia, including 118 HSSs, 165 PSTs, and 43 ISTs majoring in chemistry, were invited to complete an online -Ionization Energy Diagnostic-Modification (IEDI*M) test. The test consisted of 12 three-tier diagnostic items. The study indicated four substantial alternative conceptions were acknowledged: conservation of energy, half-filled sub-shells or stable fully-filled, octet rule framework, and relation-based reasoning. ISTs performed better than HSSs and PSTs on the understanding of ionization energy. The study has also specified the distribution of ionization energy conceptions of Group 1 and 2, and Period 2 and 3 on the periodic system. By utilizing the IEDI*M, the percentages of alternative concepts decreased from one-tier to two-tier and from two-tier to three-tier. This study gives some implications for the government, policy-makers, chemistry teachers, preservice teachers, and university faculty members.