Table 1 Summary of the learning sequence implemented in the experimental group
From: Effect of a STEM approach on students’ cognitive structures about electrical circuits
Activity | Description | Curricular contents about electrical circuits | Learning objectives regarding electrical circuits |
|---|---|---|---|
Activity 1 (90 + 90 min) | This activity began with a short text in which students were faced with a problem: they had to illuminate a room in a house. This activity allowed students to formulate hypotheses, plan a laboratory experiment (construction of electrical circuits with different configurations and measurement of the intensity of electric current and voltage), and perform it | Simple electrical circuits Symbolic representation of electrical circuits Electrical circuits with lamps in series and in parallel Measurement of the intensity of the electric current and voltage (using an ammeter and a voltmeter) | Plan and assemble simple electrical circuits, schematizing them Measure electrical physical quantities (voltage, electric current) using measuring devices and using the appropriate units, checking how the voltage and electric current varies in associations in series and in parallel |
Activity 2 (90 min) | This activity began with a short text in which students were faced with a problem: they had to select a material to isolate an electric wire. A set of materials was available, and the students planned and performed an experience that allowed them to evaluate what was the most appropriate material | Electrical conductors and insulators | Give examples of good and bad electrical conductors |
Activity 3 (90 + 90 min) | This activity was based on the nature of science, and more specifically on the life of George Simon Ohm. The students investigated about the life of George Simon Ohm and about arguments that illustrate his ideas and work regarding Ohm's Law. The students later planned an experiment to verify Ohm's Law and constructed graphs that allowed them to explore direct and inverse mathematical relationships between variables. The analysis of graphs also allows students to give sense and define electrical resistance. Students can explore how electrical resistance is measured | Ohm's Law Electrical resistance | Relate electrical currents at various electrical points and voltages in simple circuits and evaluate the association of receivers in series and in parallel Measure electrical physical quantities (resistance) using measuring devices and using the appropriate units Enunciate Ohm's law and apply it |
Activity 4 (90 + 90 min) | In this activity the students applied the acquired knowledge in the previous activities to build an electrical artifact, combining the engineering and technology components. The task was contextualized on NASA's theme "Mars Mission 2020" (https://mars.nasa.gov/mars2020/mission/overview/). Students had to visualize some videos that show the various types of robots created by NASA. After viewing the videos, students were asked to identify some of the features of the robots. Then, the students received a kit with different components and developed their projects that go through several phases: plan and draw (sketch), assemble the circuits, confer the electrical diagrams, and program the sensors (ultrasonic, temperature, and humidity) and movement of the wheels, until they reach the final product (shape and esthetics) | Apply the acquired knowledge to build an electrical artifact | All the above |