This Brazilian-based study contrasts the mental models of secondary school students and electrical engineers, demonstrating approaches needed to successfully explain the behaviour of components in circuits. It also suggests electricians can succeed without a full understanding of current.

Evidence-based suggestions

• Teachers should provide models for current to enable students to successfully construct working circuits.
• Students progress through:
  • the use of better-structured problems to challenge inadequate models
  • the use of a richer vocabulary to differentiate between basic concepts
  • moving from qualitative to quantitative models
  • moving from macroscopic to microscopic models of current (describing electron flow)
  • introducing causal models (explaining why electrons flow)
• Models should introduce the appropriate vocabulary, and define the parts of the system and how they are interrelated.

Learners’ ideas

• Students have difficulty differentiating between current, energy, electricity and voltage.
• Current is seen as ’something’ flowing through the circuit, from the battery to the bulb very much like water in a hydraulic circuit. This thing flowing through the circuit is sometimes referred to as energy, sometimes as electricity or simply as the current.
• Students believe that current travels quickly around the circuit and is used up in the bulb.
• Many students attempted to light a bulb using only one connection to the battery.

Study Structure

Aims

To discuss mental models of electricity and present the findings of empirical research involving Brazilian students and professionals.

Evidence collection

Evidence gathered through semi-structured interviews involved simple battery and bulb experiments. Participants predicted, observed, and explained outcomes. Transcribed interviews were qualitatively analyzed.

Details of the sample

The sample consisted of 28 secondary school students (aged 15 to 17 years), 10 untrained practitioners, 7 trained electrical engineers and 11 secondary school physics teachers.