This use of production techniques refers to specific attempts to increase viewer attention and learning by highlighting important elements of a video presentation, cueing and focusing the viewer’s attention, and clarifying the content to ease comprehension. In general, these techniques have been more successful than efforts to raise the learner’s general level of arousal or appeals to the viewer’s emotions and preferences.
Zooming has been used to attract the viewer’s attention, to focus the learner’s attention on the important parts of the visual image, and to supplement or supplant the learner’s skill in relating details to conceptual or perceptual wholes. Research into the relative effect of dollying and zooming on the ability of the viewer to build an accurate mental model of a physical space, based on a video “tour” suggests that dollying provides additional perceptual cues not available from a zoomed image, because of the parallax cues and more realistic changes in the relative location of objects as the subject moves through a scene. For instructional video, students apparently prefer presentations that use simple, fixed, and consistent shot lengths to presentations that vary the location and the length of shots, contrary to the professional judgment that a variety of shots is necessary to sustain viewer interest and attention.
Camera angles are important whenever an on-screen dramatic character is used to convey information. In general, a low-camera angle increases the positive perception of any on-screen character, whereas a high-angle shot results in more negative perception by viewers. Experimental data suggest that presenting a narrator, lecturer, or other on-screen “expert” from a half profile angle, so that the speaker is perceived as speaking to a listener just off-screen, increases the perceived reliability and expertise, compared to a direct, full-face presentation into the camera. In persuasive presentations, such as commercial or political speech, eye contact is positively correlated with the presenter’s perceived honesty, forthrightness, energy, and forcefulness.
A more explicitly instructional issue concerns the most effective camera angle with which to present a demonstration of a procedure. The research evidence confirms that, whenever possible, the demonstration should be presented from the perspective of the person performing the procedure to avoid forcing the viewer to mentally adjust the image. Other compositional effects that have been confirmed by experiment suggest the value of placing the most important visual object at or near the middle of the screen, and the importance of avoiding unexplained reversal of the viewing angle.
Editing techniques influence the viewer’s level of attention, comprehension, and retention though control of the pace of a presentation. Editing techniques can also be used to cue learners about how to segregate and organize different pieces of information, and the relationship between items of information within an overall context.
Appropriate cutting rates depend on the complexity of the content. Eye movement studies have shown that sustained focus on a narrator’s face creates for the viewer’s gaze to wander over the screen; whereas, if the cut comes too soon, viewers report irritation at not being able to assimilate the information in each shot. Furthermore, viewers tend to prefer video presentations that have been cut into a series of shots over ones that are uncut, continuous sequences. Cuts apparently have only a partial effect on how viewers organize the information they view on the screen. Viewers tend to segment information at cuts that coincide with major structural breaks in a presentation, but many intervening cuts are not noticed and play no part in the way material is chunked for recall.
Finally, specific editing techniques can influence the way a viewer perceives the character and the qualities of a presenter. For example, the insertion of audience reaction shots can influence a speaker’s perceived popularity, interest value, judgment, and instructional ability. Changing the context of a speaker’s statement from a prepared speech to a response to a question by inserting an “interviewer” shot has the effect of increasing the speaker’s perceived tension, sincerity, and understandability. Finally, increasing the cutting rate of a presentation increases the perceived vigor, potency, and activity level of an on-screen presenter.