Opacity of Radiography, Perplexity of Teachers and Pupils in Primary School

Abstract

Difficulty in interpreting X-ray photographs has been analysed in three situations. confronted with a photocopy of a hand and with an X-ray photograph of a hand, pupils (8–11 years old) used the word “radiography”, and associated it with a medical procedure. However, they did not mention X-rays nor understand the idea of transparency/opacity to X-rays confronted with a set of X-ray and other photographs of hands of children at different ages, future teachers of primary school spoke about X-rays, their medical use and their dangers, but misunderstood the transparency of cartilage to X-rays, and often confused the different levels of grey in X-ray photographs with those of classical photographs of the skeleton. 16 French textbooks for primary schools were analysed: they did not help either pupils or teachers, because the technical aspects of making X-ray photographs was never explained in the captions of such images, which are often coloured without any explanation of the colours. We finally identified three categories of obstacle: epistemological ones (transparency/opacity, X-rays); psychological ones (only doctors can understand these images); and didactic ones (confusing use of images in several school textbooks). We propose some didactic solutions to try to overcome these obstacles.