Overhead projectors (OHP)

Overhead projectors (OHP)
An Overhead projector is a small portable machine which
shines a light through a sheet of transparent plastic. We
can write on this sheet of plastic and the light shines it onto
the wall or your white board or a blind pulled in front of
your blackboard. Usually an Overhead projector is called
and OHP and the sheets of plastic are called OHT,
Overhead transparencies.
Joanna Baker, teacher and teacher trainer
- Teaching With Technology, Programme 1
Like the blackboard, an OHP is used to display information to a class. Here are some reasons to use it:
• You can prepare OHTs in advance, either written or typed. This is a way to make sure your materials are clearly
presented.
• By preparing in advance you save time in the classroom.
• Using an OHP you don’t have to turn your back to the class as you do when writing on the board. You can face the
class and what you write in front of you is projected behind you.
• You can use prepared OHTs again and again. When you clean a board, the information is gone for good.
• You can use it for drawings and illustrations that might be difficult as well as time-consuming to do freehand on the
board.
Here are two ways of using an OHP: