Why this approach is important

Teachers recognise that practical work is an important part of learning in science and can have several different purposes. If you teach large classes with restricted specialist facilities and resources, this will often mean that your students will not be able to do the practical learning activities themselves. You will need to use classroom demonstrations.

Practical demonstrations can be used to illustrate particular concepts, to show students how to carry out specific laboratory techniques (for example using a particular piece of equipment) or to develop students’ observational skills. The purpose of the practical demonstration will depend on the topic, the students involved and the time and resources available.

All practical demonstrations need careful planning to be effective learning experiences. You should be clear about what you want to achieve and how you will ensure that your students are fully engaged. When students are not adequately engaged they do not learn effectively. In this unit the focus is on practical experiences in the ‘light’ topic for your Class X students.

Learning about light involves learning and applying definitions and conventions such as how to measure angles of incidence, reflection and refraction. These are easy to illustrate with a practical demonstration. Demonstrations can also help your students to understand the construction of ray diagrams and the nature of images formed by objects at different distances from lenses.

Improvements in your students’ understanding will be greater if they are actively involved in the demonstration, not just passive observers. Active involvement means that your students are thinking – they are cognitively active. Some ways to do this are to involve them in observing the images and constructing the diagrams as you direct attention to relevant features and introduce the correct terminology. You can also use demonstrations to probe your students’ understanding as they progress through the topic.