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Overhead Transparencies

The overhead projector, because it is designed to be operated by an instructor at the front of a class or audience, is a perfect example of an instructional aid.  As an aid, the medium is flexible, convenient to use, and, when used well, of great benefit to both instructor and students.

Preparation of artwork for overhead projection is simple, many instructors prepare their own transparencies, either by hand or with mechanical lettering and drawing.  Drawings made on paper can be made into transparencies by several methods the use of a modern photocopier is most common.  It is possible to print or to copy directly onto a transparency using a modern laser printer or photocopier.  It is important to ensure the copier has been set for transparencies so it prints correctly.

Relating Overhead Transparencies to Instructional Objectives

Class of media: Instructional aid.

Characteristics: Still visual (limited capability for motion).

Application to types of learning:

Cognitive objectives:  Overhead transparencies can be used to teach recognition of, and discrimination among relevant visual elements:

Teach recognition of unfamiliar objects or things  by displaying visual representations.

Teach discrimination skills by comparing and contrasting pictured objects.

Enhance teaching of discrimination by exaggerating differences in objects that might otherwise be overlooked.

Demonstrate relationships as interaction of objects in motion

Show principles of operation of objects that normally have working parts enclosed and invisible for observation.

They can also be used to teach rules, principles, or concepts:

Reinforce the comments of an instructor.

Display words or phrases to be stressed or present an outline of points to be shown in coordination with the instructor’s presentation.

Clarify and reinforce the instructors commentary by displaying elements of the lesson content.

Provide visual cues for the instructor to follow in presenting the lesson.

Psychomotor objectives.  Limited application. May be used to show positions of things or people in motion before demonstrations or practice.

Affective objectives.  Generally does not apply.

Advantages and Disadvantages of Overhead Transparencies

Advantages

• Allows freedom for an instructor to edit, sequence, and revise instructional materials.
• Allows instructors to face an audience in a lighted room to permit interpersonal exchange and to encourage questions and discussion.
• Permits the instructor to write on a transparencies and to use a pointer or to edit items during projection.

Disadvantages

• Limited to use as an instructional aid by an instructor or by students. Seldom used as an instructional medium.
• Widespread distribution of transparencies may be less convenient than other options.

Considerations for Selecting and Developing Transparencies for Instruction

• Is the lesson material to be presented by an instructor? (If the answer is NO then you should not use this medium).
• Will exact reproduction of the visual and oral information be required each time the lesson is presented?
• Is the verbal message to be presented by the instructor long and complex, suggesting that visuals could help the audience concentrate, and fix its attention on an orderly progression of ideas?
• Are there parts of the verbal message that can be better expressed visually or with visual support than by words alone? (“One picture is worth a thousand words.”)