The effect of macroscopic and submicroscopic pictorial representations on pre-service science teachers’ explanations

The purpose of the current study is to examine whether different types of chemical representations
(macroscopic vs. submicroscopic) stimulate meaning construction differently. The sample included 152 pre-service
science teachers in Oman. The instrument included a diagram of the reaction of sodium in water and asked
participants to explain how heat transfers from the water around the sodium piece to the thermometer and how it
causes the mercury level to rise. Two different versions of the diagram were designed: macroscopic and
submicroscopic. The two versions of the instrument were distributed randomly to participants. A rubric was
designed to evaluate participants’ explanations at the submicroscopic level. The results show that participants who
received the submicroscopic diagram statistically outperformed those who received the macroscopic. These
findings indicate that 1) adding submicroscopic details to the macroscopic experimental sketch encourages
students to think at the submicroscopic level; and 2) students do not spontaneously think at the submicroscopic
level.