INSTRUCTIONAL TECHNOLOGY 3(2+1)

Lesson 30 : Three Dimensional Visual Aids

Three dimensional visual aids

1. Model
2. Specimen
3. Object
4. Diorama

Model:

Model is a replica of real object it may be life size, smaller or larger than the things they represent. Model is used when the use of real object as a visual aid is not applicable. Where sight or sometimes touch in understanding of the subject is needed.

Objectives:

1. To give first hand information about an idea to the participant.
2. To inspire people to work on the real thing.
3. For easy understanding and explaining a subject which is very difficult or sometimes impossible to bring to the class room like a paddy field or a human heart.

Types of models:

Scale models: Represents external form and shape of original object and prepared to scale (smaller or larger) e.g.: Tajmahal, insect etc. Cross Sectional Models: Reveals internal structure of real object e.g.: Heart Mechanism, oil engine etc. Working Models: Shows operational of essential parts of real objects e.g.: Working telephone, oil engine etc. Simplified Models: Shows simple features of the external form of the real objects without reproducing the original in precise proportion. E.g. - Animals, birds, fruits etc.

• Mock-ups: A mock-up refers to a specialized model or working replica of the object being depicted. In a mock-up, a certain element of the original reality is emphasized or highlighted to make it more meaningful for the purpose of instruction. Mock-ups are often used in technical institutions for training purposes.

Principles of using Models:

1. Arrange display of models to stimulate interest and arouse curiosity
2. Secure models when real objects cannot be brought in to the classroom
3. Use mock-ups or synthetic devices to show functioning of complete units
4. Explain that any model or mock-up is incomplete or out of its natural setting
5. Encourage making of models and mock-ups in certain subjects
6. Avoid too large, unorganized or over-elaborate displays of models
7. Avoid using models or mock-ups too complicated for maturity of the group

Advantages

• Allows learners to see the equipment or operation in real life.
• Other senses brought into play.
• The three dimensional form affords a back for concrete experience.
• Reduction/enlarge of objects to a convenient size is possible.
• Provide interior views of objects which are normally invisible.
• They afford dissection and assimilation of parts.
• A model provides the correct concept of an industrial unit or a bridge or a dam like, the Bhakra Dam etc
• A working model explains the various processes of objects and machines.

Limitations:

1. Many items obviously cannot be brought into the class room
2. Models are not available for many items
3. Good models are expensive or very time consuming to make or have made
4. Some danger involved for learners
5. Time and money usually limit the number of learners who can work with items individually

Mock-ups:

A mock-up refers to a specialized model or working replica of the object being depicted. In a mock-up, a certain element of the original reality is emphasized or highlighted to make it more meaningful for the purpose of instruction. While a model is a recognizable imitation of an object, a mock-up may or may not be similar in appearance. Mock-ups of aeroplanes, auto-mobile engines, bridges, ships and tunnels etc, may be demonstrated for explaining their structure and actual working. Mock-ups are often used in technical intuitions for training purpose.