The Usefulness of Computer-Based Presentations in a Teacher Directed
For ease of discussion, Microsoft PowerPoint presentations will be
used to represent Computer-based presentations in general and the
advantages and capabilities attributed to that specific software can
usually be generalized to other presentation software.
In the usual classroom situation, the teacher orchestrates the presentation
of course content (some combination of concepts, facts, and processes)
to learners who are expected to comprehend and retain that content
to some predetermined degree. The means of presenting the content
elements varies with subject matter, the nature of the desired outcome
(e.g. fact retention, technique application, etc.), and the professional
judgment of the teacher. Typically, the teacher works from notes,
either mental or written, detailing what that teacher intends to do
during that class period.
The teachers notes are the result of his pre-class efforts
to program the combination of content, activities, and instructional
techniques that will result in the greatest intended learning.
The notes provide a to-do list so that classroom elements
are not inadvertently left out. Some of these elements are content
oriented and will usually be specifically presented to the students
-- written on the chalkboard, some will be parameters of an intended
activity (e.g. add two complex numbers or add 2+j6
and 4+j3) which may or may not be specifically presented, and
some will be reminders for the teachers use only. PowerPoint
presentations specifically provide for this function including separation
of teachers-use-only reminders from those available
to the class members.
In most classes the sequence of content elements is an essential
factor. They are usually presented to the students as they are
needed as a means of focusing student attention on the matter at hand.
This can be done by writing on the chalkboard but difficulties of
this method in deflecting the teachers attention from the class
is well known and has been a main reason for the widespread adoption
of overhead projection transparencies. Unfortunately, the gymnastics
required to cover part of the transparency with a paper and slide
it down to reveal points one-by-one have diverted teacher attention
away from the class almost as thoroughly as turning at least sideways
(not to mention turning fully away from the class) to write on the
focus technique for controlling student attention is even more directly
addressable in PowerPoint since, in addition to hiding what is to
come, the visual pull of preceding points can be sharply diminished
by automatically changing color to something only slightly different
from the slide background thus leaving the current point as the highly
visible one. The preceding points are still visible for the
students whose note taking has fallen behind.
On a personal note, I have used both self-prepared and publisher-prepared
transparencies in several different courses taught over many years
at RCC and found, almost without exception, the spontaneous interaction
I was used to having with my students disappeared. I have used
PowerPoint in similar situations with no such loss of interaction.
I attribute this to the simplicity of presentation control in the
classroomall the mechanics of transitions and animations have
been taken care of before class and my attention can stay on the students.
By duplicating the first slide and removing all slide transition
and animation effects from the second slide, they appear to be a single
slide with an instant change to the new colors.
permits the display of graphic information (photos, drawings, diagrams,
etc.) but, contrary to normal slide projection, the graphic can be
reduced in size to permit simultaneous display of explanatory text.
The explanatory text is easily positioned with the graphic and such
things as arrows and colored circles are easily applied to highlight
features within the graphic. These text and pointing elements
are under the author's control as to how and when they will appear.
For example, the name and arrow for each feature can be made to appear
only when the teacher is ready to discuss that feature or the arrow
could appear and the name only appear after the class has had their
chance at identifying that particular feature.
Background graphics are also under the control of the author/teacher.
Not only can a specific graphic be selected but the slide can be "layered".
Text can be read through the controllable transparency of a diagram
appearing in the foreground, or it may appear in the foreground on
top of a background diagram, or a diagram/text may be moved on top
of another graphic to hide it thereby providing a sequence of views
or to focus attention, etc.
The creation of handouts for the students is certainly facilitated
with the choice of three slides per page which includes lines adjacent
to each slide for student use in adding their own notes being particularly
All in all, computer presentation software such as PowerPoint has
many features which can assist the teacher in the classroom in the
effort to effectively convey concepts and facts, specify parameters
of activities, and provide enriching illustrations. There are
so many features, in fact, that an article like this cannot conclude
with out a word of warning: It is unfortunately easy to employ
such a variety of features that the focus of student attention is
pulled to the mechanics of the presentation rather than to the subject
matter content. Continually varying the entry animation of text
and the use of multiple contrasting text colors are just a couple
of roads leading to reduced effectiveness.