This US study compared Reform-Based Teaching and Reform-Based Teaching with Multiple Representations programs in teaching the particulate nature of matter to students aged 16-17. The latter was more effective in correcting students' misconceptions.

Evidence-based suggestions

• Use various linked representations in their teaching, encouraging a multi-modal approach.
• Use visual tools such as animated or static particulate representations, as well as allow students to represent their understandings pictorially when appropriate.
• Make efforts to implement effective formative assessment (for instance, student activity sheets focusing not on prescriptive instruction but on guiding questions, and prompts implicitly aimed at promoting student metacognition).
• Teachers who read individual students' written products could gain insights into their students’ understandings and identify common conceptual issues.

Learners’ ideas

• Some students believe that matter is continuous (no gaps between particles), particularly in the solid state.
• Students can think that the spacing between particles of liquids is intermediate in comparison with the spacing between particles of solids and gases.
• Students may believe that some substances (e.g., air, and some other gases) exist between the particles of matter.
• Students may think that particles of solids do not move at all.

Study Structure

Aims

1. What types of conceptual understandings are held by high school students about the aspects of the particulate nature of matter just before and immediately after completion of the two different instructional interventions; namely, Reform Based Teaching and Reform Based Teaching with Multiple Representations?
2. How do high school students' types of conceptual understandings of the particulate nature of matter differ immediately after completion of the Reform Based Teaching with Multiple Representations and the Reform Based Teaching instruction?

Evidence collection

Both student groups completed pre- and post-intervention questionnaires, followed by interviews with selected students. Data were collected through an open-ended questionnaire (Nature of Matter Diagnostic Questions), based on previous research items with some new additions. Pre- and post-intervention questionnaire results were coded and categorised into conceptual understanding types. Post-intervention codes were combined with interview data where necessary. Research question 1 used a direct comparison of frequencies, while research question 2 employed a sign test for analysis.

Details of the sample

The sample contained 42 students, ages 16 and 17 years, from two separate classes taught by the same teacher and from a high school in a suburban area of a large city in the US Midwest.