21.6: Video
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With respect to teaching, you can use video, which is usually combined with audio, effectively for:
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demonstrating procedures, changes, and processes
- Learning can be especially effective when the learner can control the video with features, including playing when ready or replaying as needed.
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teaching attitudes and values
- Emotional material and/or real-life examples can be shown.
- Text may be needed to help explain the attitudes and values.
- making abstract concepts concrete
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classifying and comparing information
- For classifying and comparing information, video is particularly valuable when the information can be quickly accessed.
Video can also be useful for:
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gaining and holding attention as well as motivating learners
- This can be done through special effects, colour, motion, audio, and historical clips.
- This can lead to increased retention and recall of information.
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introducing topics or procedures
- This can be easy and pleasant for students especially when the alternative is lengthy text.
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presenting visually rich material that would otherwise be hard to explain (e.g., chemistry and physics experiments, how an amoeba moves, heart valves opening and closing, and human interactions)
- Information that needs to be visual or have realism can be presented. Examples of these include the courtship rituals of animals and human behaviours for changing attitudes.
- Audio, such as lung and heart sounds, can also be presented.
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testing
- Testing with video can be much more realistic than testing via text.
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Use video to teach skills that are difficult to explain with other media.
The strengths of video are more evident if you tell the students what they are going to learn and what they should focus upon before they view the video. A video’s effectiveness also relates to how well the material attracts and directs the learner’s attention. Learners tend to have a short attention span for video. If the Grand Canyon, one of the world’s most spectacular sights, holds a viewer’s interest for an average of 90 seconds then imagine how long your video clip can hold your learner’s attention. You can minimize this problem by presenting short clips, as short sequences are helpful in maintaining student attention and interest. This also helps keep the message focused on the learning outcome being taught.
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Prepare students before they watch a video. Let them know where to focus their attention.
There can be problems with video. Most students remember generalities rather than details. Also, video sometimes provides information at a fast rate. So, you should likely plan activities to help learners retain the material and also keep the video available to students for studying. In some situations, you should let the learners 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.
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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 non-action 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.
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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.
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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.
- Although consumer-level digital video equipment tends to be affordable, professional-level equipment can be costly.
- Better filming equipment has high sensitivity (this is a measure of the minimum amount of light to make a usable picture—measured in units of lux), high resolution (this determines the picture’s sharpness), and dynamic response (this is the ability to detect rapid changes in a scene’s light intensity).
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High-quality video takes time and expertise to develop.
Gathering Existing Materials
Before you go to the effort of recording any video, determine whether any suitable materials exist. Gathering existing materials can save you significant time and money if you do not have to “re-invent the wheel”. For any materials you can get, be sure to:
- get copyright clearance in writing
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get original materials
- Each succeeding generation has poorer quality.
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get materials in the format you will use, such as mini DV tapes
- If you transfer material from one format to another, some image quality will be lost. It also costs time and money to transfer material between formats.
- Existing materials are often found in a variety of formats (e.g., HD, mini DV, film, one inch, 3/4 inch, Betacam SP, 16 mm, Hi8, 8mm, S-VHS, and VHS).
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determine whether the material’s quality is acceptable
- Sometimes poor quality is better than students never seeing the material.
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Using existing materials can save you time and money.
Many high-quality generic clips are available for a fee in a variety of formats. If it is important to you, ensure that you can distribute the clips royalty-free.
You may have problems in gathering existing materials, in that:
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copyright clearance may cost money
- Costs can range from being expensive to free.
- it may not be possible to locate the copyright owner
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the materials may not arrive or it could take a long time to receive the materials
- Sending materials can be a low priority of copyright owners.
- copyright clearance may not be granted for some needed materials
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some materials may not be exactly as you need
- For example, video materials designed to be played linearly, such as in movies, often have audio that overlaps scenes in that the audio may start before or end after the specific video is seen. Also, the video is usually not designed to be shown in a series of short clips, as can be preferred in online courses.