Education for a Digital World Advice, Guidelines and Effective Practice from Around Globe, 2008a

21 – Media Selection
control the video (e.g., slow forward, step forward, step
backward, slow backward). This is particularly helpful
for reviewing psychomotor skills such as studying procedures
and noting detailed information.
VIDEO COMBINED WITH OTHER MEDIA
If you combine video with audio, you can effectively
teach attitudes and provide elaborations. Note that video
combined with audio requires more mental processing
than either alone. Consequently, you can overwhelm
students with more information than they can mentally
process. One solution is to put pauses after complex
elements to allow learners to mentally “catch-up” before
you present new material.
Video combined with audio can depict events faster
than can be done with only text. However, students perceive
video as being easier than text and tend to spend
less effort in learning from video than text. Consequently,
students may learn less from video than from
comparable text. You can enhance learning with video
by cuing the learner, providing interaction, and keeping
the video clips short.
Since video tends to be weak at teaching detailed information,
provide video control and text-based summaries
to help with this problem. Consider combining
video with text to provide practice and feedback.
Practical Guideline
Video has many effective uses but is weak at providing
detailed information.
DIFFICULTIES WITH PROFESSIONAL QUALITY
VIDEO
Professional quality video usually requires a large
amount of storage space when digitized and significant
costs, time, and expertise to develop.
Digitized video (for both professional and nonprofessional
productions) requires a large amount of
storage space. Expect to make some compromises.
• Modern video cameras automatically digitize video.
However, if you are working with old sources, you
may need to convert analog (smooth and continuous)
signals into a finite amount (depending on the sampling
rate or number of measurements taken) of
digital or binary information (1s and 0s) that computers
store and process. The large amount of storage
space needed for digital video can be a significant
problem, especially for CD-ROM distribution, unless
compression techniques are used.
• Minimize digital storage requirements by using short
clips and only use the amount of video that is necessary.
Some video clips, such as interviews, may not
require full-motion, full-screen, or full-colour presentations.
Although video is typically shown at a
frame rate of 30 frames or images per second, as a
rule, action sequences should play at a minimum of
20 frames per second while you can reduce nonaction
clips (e.g., “talking heads”) to 10 frames per
second if you need to save disc space or reduce
bandwidth requirements. Screen sizes for video generally
range from 640 × 480 down to very small sizes,
depending on the computer system and/or speed of
the Internet connection.
• Depending on the computer’s speed, computer’s
memory size, and the file size, there may be a significant
delay while large video files are loaded. Short
video clips are often preferable.
Practical Guideline
Estimate the amount of data your final product
will need to hold to ensure that your data will fit
on the selected storage medium.
Producing professional quality video particularly
needs justification since you will incur significant costs
for their production:
• Justification can be from the motion needing to be
taught being unfamiliar or difficult to perform.
• Justification can arise from concepts being easily and
best understood with video.
• Justification is easier if the material will be useful for
a long time. This is particularly important with video
since it can be expensive to update the video. Filming
and editing can have significant costs.
• Typical costs per day for a camera operator, other
personnel such as a sound person and actors, a quality
camera, and other equipment such as lights tend
to be expensive, especially when paying for talented
individuals.
Projects requiring professional video can take a large
amount of time to produce. For example, a relatively
simple project, such as creating a resource that covers
each step of disassembling and assembling an aircraft
engine, can require 200 hours of development time.
Many projects need specific expertise such as media
specialists and instructional designers who specialize in
multimedia applications.
Professional productions also require relatively expensive
filming equipment.
332 Education for a Digital World