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Class 8 avaids d.kavitha
1. CLASS -8 -
EDUCATIONAL AIDS
PROJECTED AIDS- OHP
D.KAVITHA
ASSOCIATE PROFESSOR IN NURSING
DEPARTMENT Obs& Gyn
MPG&RIHS,PUDUCHERRY
KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR 1
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3. INTRODUCTION
Rapid contribution of science and technology
in the development of newer projecting
audiovisual aids has revolutionized the field of
audio visual aids.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
4. DEFINITION OF PROJECTED
VISUAL AIDS
Projected visual aids are pictures shown upon
a screen by the use of a certain type of
machine.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
5. ADVANTAGES OF PROJECTED
AV AIDS
Provides greater enjoyment in learning
Stimulates more rapid learning
Increases retention: larger percentages and
longer retention
Compels attention
Enlarges or reduces actual size of objects
Brings distant past and the present into the
classroom
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
6. SLIDES
OHP
FLIMS
TV/VCR/VCD/LCD
CAMERA MICROSCOPE
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
7. OVER HEAD PROJECTOR-
INTRODUCTION
Overhead Projector was created by Jules
Duboscq, in 1870s.
Used during the Second World War
Used as a teaching tool since 1950s.
Become popular easy to used
Provides an interactive environment for
educators.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
8. OVER HEAD PROJECTOR
Over head projector helps in the projection of
transparencies with brilliant screen images
suitable for use in a lighted room. It is a very
vital teaching aid and has made teaching
simple and easy
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
9. DEFINITION
Overhead Projector: machine designed to
project an image, text, and drawings onto a
small screen or whiteboard
Transparencies: pages transparent and
flexible used to place information and images
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
11. Parts of over head projector
1. Metal box with a 1000w bulb for an indirect
projection / 600w Halogen Lamp for a direct
projection and a concave reflector
2.Transparent writing place 25x 25cm
3. Fresnel lens is used to form a converging
beam of light . Which illuminates the stage
area uniformly and converges to the projected
lens
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
12. 4. The projection lens is used to form
converging beam of light . Which illuminates
the stage area uniformly and converges to the
projected lens
5. A surface aluminized mirror / very thin flat
mirror serves to rotate the path / light by 90˚
6. Small exhaust / cooling fan in the projector to
blow out the excess heat produced by the bulb
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
13. 7. Fresnel lens protected by a glass plate.
8. Knob – the projection distance can be
adjusted in accordance with the desired
picture size
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
14. Accessory structures
Screens may be aluminum coated .
Glass bead / flat white screen
Stabilizer to prevent voltage fluctuation
Pointer
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
15. How the OHP can be used in
different Instructional Situation
Expository teaching of virtually any type
Group learning situations
Enabling members of a group to display
material that they themselves have produced
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
16. CONT….
To present activity plan or objectives
To show tables
To systematize the information to be conveyed
To list brain-storming idea
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
17. OHP transparencies
Size – 7x7(or) 10 x10”( 25x25cm)
MATERIALS CAN BE PROJECTED
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
18. GUIDELINESS-HOW TO USE
THE OHP
Located it in a place
where everybody
can see the screen.
Arrange the
projector and screen
in a way to minimize
it. It should have
appropriate angles
in horizontal and
vertical planes.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
19. CONT…
Adjust the distance
from projector to
screen so the image
fills the full area
Make sure the
acetate and open
head surface are
clear and free of
dust or dirty
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
20. STANDARDS IN USING OHP
Make the text,
illustrations or pictures
in your transparencies
big enough
Schematize: present
essential points, one
transparency every 2 or
3 minutes
Use a pointer to
emphasize points on
the acetate
Plan for a dramatic
presentation
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
21. CONT…
Check visibility; do
not block the screen
Plan your narration.
Turn on the lamp
only if there is a
transparency on the
projector
Put off the projector
for prolonged
explanations, or when
it is not needed
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
22. DESIGNING OHP
TRANSPARENCIES BASIC
PRINCIPLES
There two basic
Principles:
1. Do not try to put
too much
information on a
single
transparency.
2. Use a clear,
systematic layout.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
23. PRODUCING COMPUTER
GENERATED OHP MATERIALS
Use computer to design and produce
OHT
Create both alphanumeric and
graphic materials and print them out
in OHP transparency form - in full
color, and with whatever size of
lettering is wanted
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
24. DISPLAY TECHNIQUES
Progressive
Disclosure Involves
covering up all or
part of the material
on a given
transparency, and
progressively
revealing the
material as the
presentation
proceeds
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
26. Display Techniques
c) Use of overlays
Whole area of
transparency is
revealed from the
start, with additional
information being
added to the original
display by
superimposing
further
transparencies on
the original.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
27. DISPLAY TECHNIQUES
c) Use of Overlays
1. To lay separate
transparencies
2. Make use of hinged
overlays
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
28. Tips to use OHP Effectively
1.Just write key points on
transparencies
2.Keep transparencies simple -
6X6Rule
3.Use 18 point type- no more than two
type styles
4.Mix upper and lower-case letters for
easy readability
5.Do not use exclamation marks, they
look like number one.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
29. Cont…
7. Do not turn off all room lights
8. Turn projector lamp off during
discussions
9. Never stand anything between the
projection and screen
10.Give people time to read
11.Talk to your listeners not the screen
12. Before moving wait for period time to
cool Down - bulb may explode.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
30. FOR PREPARING A
TRANSPERENCY
Six lines per transparency
• Six words per line
• Six mm smallest letter size
• Six cm (3+3 on each side) margin
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
32. METHOD OF USING OHP
Place the OHP on a stable table with the
objective lens
facing the screen behind the teacher.
Put the cord plug into power wall socket.
Switch on the blower first and then the bulb.
Place transparency on the glass top.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
33. Move the objective lens and mirror assembly
up and down to get the image in focus on the
screen.
Explain about the material on the
transparency from behind OHP with a strong
pointer.
The handle of the teacher should not come on
the slide.
Make your points short and simple
Remove what is not needed.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
35. DO’S
Focus and position image before presentation
Stand to the side of the screen
Turn off projector when not in use
Letters the larger the better
Use colour to attract attention
Put captions on top.
Have images in to two-thirds of visual position
image at the top of the screen
Use pen or ruler to point
Use upper and lower case letters
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
36. DON’T’S
Walk or stand in front of the screen.
Leave the projector on when you’ve talking
about
Something
Write closely on the whole of the transparency
sheet
Have images type-written or too small
Use black and white visuals only
Use finger to point
Use only capital letter
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
37. CHECK LIST FOR EFFECTIVE
USE OF OHP
1. BEFORE THE LESSON
Position the screen
Obtain correct image by moving machine
backward/ forward in relation to the screen
Focus image sharply
Place masking sheet to hand
Place the transparencies in correct order
Check table and head for dust
Ensure that spare lamp is available
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
38. DURING LESSON
1.switch off when
Placing transparency on table
Removing transparency
Point has been explained
2. use pointer to indicate
3. use mask to reveal the points in a step by
step
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
39. AFTER LESSON
Donot move the OHP while lamp is HOT.
Never disconnect from main supply while the
fan is operating
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
40. ADVANTAGES OF USING OHP
It is portable
Get transparency materials in low cost
Located in front of the room
Used in a room with normal lighting
It is simple to operate
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
41. ADVANTAGES OF USING
OHP
Used as a chalkboard or market board
Modify transparencies during the presentation
You can write without turning your back
Maintain eye contact
Audiences can follow handout or take notes
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
42. DISADVANTAGES OF USING
OHP
It requires a power supply
Needs suitable surface about four square feet
Need spare bulb in case unexpected events
Many users do not give sufficient thought to
the production of their display material
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
43. CONT…
Tendency to include too much information in a
single frame
Teachers or lectures overuse the OHP
Difficult to transport because of its weigh
Cost of materials required to operate them
Used with small audiences.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR
44. CONLUSION
OHP is a useful tool to project information for a
small audience.
It provides some advantages using it as well
as some disadvantages.
There are some usage principles teachers
should follow to make its use effective.
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KAVITHA DURAIRAJ, ASSOCIATE PROFESSOR