Students often use incoherent strategies in their problem solving involving force and motion, as revealed, e.g. when they are asked to draw force diagrams for amusement rides involving circular motion, whether in horizontal or vertical planes. Depending on the questions asked, assignments involving circular motion can reveal different types of…

It is not common to introduce current astronomy in school lessons. This article presents a set of experiments about gravitational lenses. It is normal to simulate them by means of computers, but it is very simple to simulate similar effects using a drinking glass full of liquid or using only the glass base. These are, of course, cheap and easy…

When students are forming their ideas of what will eventually become the concept of force, the images of arrows in our standard diagrams carry with them unconscious attributes of direction of movement and so on. Describes how the use of a 'symbolic representation of interactions' with double-headed arrows avoids these unwanted messages being…

Discusses: how thought experiments (TES) are presented and used in physics textbooks; how and why teachers include TES in their explanations; and what understandings students draw from TES. Indicates that TES are only one of a broad class of "acts of imagination" which are essential in physics education. (JN)

Described is the interview-about-instances method used to gain insight into children's and adults' views of the world and the meanings people have for the words they use in explaining their views. Physics teachers can utilize this technique to become aware of the various concept understandings pupils bring to physics classrooms. (DS)

Criticizes the current method of formalization in Italian schools and the use of tools of the mathematical method. Proposes a general three-stage formalization method which can used for physical quantities, the particular significance of certain quantities, and the description and interpretation of phenomena. (TW)

Attempts to show that not only can density be taught to lower ability pupils but that by doing so, there is the possibility of assisting pupils to develop their reasoning powers. Lists teaching activities that help in this process. (CW)