When constructing ray diagrams or when asked to draw the path of light students rarely draw the lines from source to object

Light, Sound and Waves


Diagnostic Resources

The following worksheets may help to identify whether students hold this particular misconception.

For more information, see the University of York BEST website.

Resources to Address This

  • Travelling light  (5-11)

    Rrf - SPT HS01 TA10

    Hang the ball from a metre rule and hold it in the beam of light between the light source and the screen. With a good black-out for the room and a strong point source of light, a striking shadow will be produced on the screen.  In developing these ideas, you are likely to find yourself sketching out ray diagrams for the children.

    View Resource
  • Ray diagrams (11-14)

    Ref - SPT Li02 TA01

    In this activity the teacher talks through the construction of a simple ray diagram for the formation of a shadow, making clear all of the conventions and other thinking behind it.

    View Resource


The following studies have documented this misconception:

  • Grusche, S. () Students’ ideas about prismatic images: teaching experiments for an image-based approach. International Journal of Science Education, https://doi.org/10.1080/09500693.2017.1312625

    Review sheet

  • Heywood, D. S. () Primary Trainee Teachers’ Learning and Teaching About Light: Some pedagogic implications for initial teacher training. International Journal of Science Education, 27 (12)


    Review sheet

  • Ramadas, J. and Driver, R. () Aspects of secondary students' ideas about light, University of Leeds Centre for Studies in Science & Mathematics Education.

    Review sheet

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