Stein, Galili and Schur (2015)

This Israel-based study assessed a new approach to teaching the concept of gravity to students aged 12-15, building a new conceptual framework based around ‘operational weight’ rather than linking weight to gravitational fields directly using Newton’s second law. 

Learners’ ideas

  • Each person/observer has a personal up-down direction.
  • Up-down directions are universal/absolute (down is the same for everyone, regardless of location).
  • Body orientation determines the up-down direction.
  • Gravitational force depends on the existence of air/atmosphere.
  • Floating objects indicate a lack of a gravitational force.

Evidence-based suggestions

  • Instruction was successful in addressing the misconceptions:
    • the existence of an arbitrary up-down direction
    • the need for objects to be heavy in order to be held by gravity
    • weight being caused by air and weightlessness caused by vacuum.
  • Successful instruction should address a representative set of physical situations that would enable students' construction of an adequate concept image.

In terms of useful activities, the researchers also suggested that starting with novel situations, instead of everyday ones, was more successful than the more popular, opposite approach. This indicated that familiarity with the situation might impede learning, since the regular environment is seldom questioned and normally fortified by a naïve account, often misleading in science.

Study Structure


The aim of the study was to compare traditional ways of teaching about gravity and weight to the researchers' novel approach.

The research question was:

  • How do middle school students conceptualize up-down direction, weight, and gravitation prior to instruction, and how do they conceptualize these concepts and their interrelation by the end of the new instruction?

This was then focused on two pedagogical questions:

  1. Which key characteristics of the new instruction (conceptual framework of weight and pedagogical method) may make the teaching of this conceptual domain effective?
  2. To what extent is it feasible to guide middle school students toward knowledge construction of weight and gravitation, based on the operationally defined weight through a short intervention?

Evidence collection

Methods included:

  • Students were asked to draw sketches
  • class discussions were videotaped and transcribed
  • questionnaire
  • drawings 
  • home assignment with five qualitative open-ended questions 

The sketches, transcribed recordings and assignment data were gathered at lessons 1, 4 and 5 of a 5 x 90 min lesson sequence.

Data were analysed qualitatively using a grounded theory approach. Data were then categorized in terms of facets and schemes emerging from the data.  Each facet represented a pattern of reasoning applied by the students to account for the particular situation.  The accumulated facets were reduced to a few schemes of knowledge.

Details of the sample

A sample of 14 students (7 boys and 7 girls) with average mathematical ability was randomly chosen from an urban state middle school.

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