16.11 ELECTRONIC VISUALS

16.11.1 Screen Design

Several studies have been conducted that investigated aspects of computer screen design. Grabinger has followed an ongoing line of research regarding display of text and other design elements* on computer screens (1984, 1897, 1989, 1993). In 1989, he did a review of the research and provided guidelines that identified specific things that screen designers ought to do. His most recent work (Grabinger, .1993) investigated viewer responses to screen designs, finding that adult viewers of instructional screens judged them primarily on two dimensions: organization and visual interest.

Hannafin and Hooper/Hooper and Hannafin (1986, 1988, 1989) also published a series of papers about screen design and layout. While their papers, much like the Grabinger 1989 paper, were prescriptive, the most enduring contribution they make is less about screen design than about facilitating individual learning styles. The problem is that screens have changed since most of the research was done, e.g., that of Grabinger in 1984. Jones (1995) has stated the situation clearly: "Screen design literature is dated, and the existing guidelines do not allow for advances in computer technology" (p. 264). Jones went on to say, "there is a dearth of research into how the screen in a CBI program can incorporate a dynamic interface to promote the acquisition of knowledge to the end of promoting and improving human learning" (p. 266).

Duin (1988) followed the best guidance available at the time and created a "well-designed CAI program" that was tested against a poorly designed program and a control group that did not use CAI. While the experiment produced some positive results regarding student attitudes toward well-designed instruction, the resulting guidelines that emerged from the study seem more suited to monochrome screens than to today's high-resolution color monitors with powerful graphics capability.

Some research relevant to screen design, of course, will prove durable. For example, the study by Herbener, Van Tubergen, and Whitlow (1979) investigated the location of objects within the visual frame. That study only considered black-and-white images and did not include motion or attempts at three dimensionality, yet the findings are instructive:

Subjects seem to consider images more active when the center of interest is higher in the frame. Subjects appear to rate images as slightly more potent when the center of interest is higher in the frame. When the center of interest is placed away from the geometric center of the frame, . . . subjects tend to rate the image more negatively. Not unexpectedly, ratings on the verticality scale are higher when the center of interest is higher in the frame; but there is also the hint ... that a given vertical position is seen as higher when it is horizontally centered (p. 87).

16.11.2 Computer Graphics

An advantage of computer graphics is that they can be drawn either statically or dynamically. Moreover, they can be called or dismissed interactively. Alesandrini (1987) reviewed the research relevant to computer graphics in learning and instruction. She introduced her chapter with the following caveat:

The effects of computer graphics on learning and motivation are only beginning to be explored. While many studies have investigated the use of graphics in traditional instruction, few studies have investigated graphics in CAI (computer-assisted instruction) or the instructional uses of graphics application software. Although the published findings are limited, many projects are currently underway to field-test the variety of uses of computer graphics (p. 159).

Indeed some of those studies are beginning to appear, but advances in computer technology are outpacing research on computer utilization. Among other enhanced capabilities of microcomputers is the ability to portray with ease graphic representations of conceptual networks. Consequently, the research questions have changed with the emerging technology, and we see studies like that of Allen, Hoffman, Kompella, and Sticht (1993) that examine computer-based mapping as a tool for curriculum development. We find current researchers turning back to basic graphing skills research as they consider the possibilities of computer-generated visualization. For example, Drahuschak and Harvey (1993) wrote an article on computer-based graphing that posed the problem this way:

The question we should ask now is this: Which instructional strategies will prove useful in developing critical thinking skills within this emerging discipline of visualization? Research performed by McKenzie and Padilla (1984), Mokros and Tinker (1987), Talley (1973), and Siemankowski and MacKnight (1971) has concluded that in order to be successful in science two critical areas must be mastered: graphing abilities and spatial abilities. Visualizing a data pattern in three-dimensional space once required a well-developed imagination. Fortunately, students today can augment their mental capabilities with the use of a computer system ... (p. 3).

To place that quotation in context: McKenzie and Padilla (1984) found that formal operational thinkers tend to score higher in graphical achievement than concrete operational thinkers. Mokros and Tinker (1987) reported that experience in microcomputer labs enhanced children's ability to interpret graphs. Talley (1973) studied three-dimensional visualization, concluding that individuals who have better visualization skills perform at consistently higher levels of conceptualization. Siemankowski and MacKnight (1971) found science-oriented students to have greater three-dimensional visualization or spatial abilities than students who are not science oriented.

16.11.3 Animation

As computer technology advances and authoring systems become more friendly and powerful, computer special effects that were once esoteric are now becoming commonplace. As a result, computer animation, which has long been around in computer-based instruction (CBI), but only as a rarity, is now a pervasive reality. Just as the incidence of animated CBI has increased, so has the research about it. Rieber (1989, 1990a, 1990b, 1991a, 1991b; Rieber, Boyce & Assad, 1990; Reiber & Hannafin, 1988; Reiber & Kini, 1991) has generated a flurry of research. Many others have contributed also, including those whose interest preceded the new technologies (Alesandrini, 1987; Cambre, Johnsen & Taylor, 1985; King, 1975; Moore, Norwocki & Simutis' 1979; Rigney & Lutz, 1975), and others in more recent times (Back & Lane, 1988; Mayer & Anderson, 1991; Torres-Rodriquez & Dwyer, 1991). Reiber (1990a) has promoted the appropriate use of animation, but cautioned that "CBI designers ... must resist incorporating special effects, like animation, when no rationale exists. . ." (p. 84).

The findings tend to be related to narrow research questions. For example, the results of the Cambre, Johnsen, and Taylor study "indicated that children learned from and liked both serious and humorous animations, especially those animations; designed for older audiences" (p. 111) Reiber, Boyce, and Assad reported that "although animation did not affect learning, it helped decrease the time necessary to retrieve information from long-term memory and then subsequently reconstruct it in short-term memory" (p. 50). Mayer and Anderson (1991) performed two experiments involving college students. In one experiment, instruction with an animation and a concurrent verbal explanation was compared to instruction where the narration was given first, followed by the animation. In the second experiment, the same comparison was made, and other treatments were added to include students who saw the animation only, students who heard the words only, or students who had no instruction (control). Students in the words-with-animation treatment performed better than students who received any of the other treatments. Reiber (1991), in an experiment with fourth-graders, "showed that students successfully extracted incidental information from animated graphics without risk to intentional learning, but were also more prone to developing a scientific misconception" (p. 318). In a study utilizing college students as subjects, Torres-Rodriquez and Dwyer (1991) set out to assess the relative effectiveness of animation, zoom-in, and a combination of animation and zoom-in. Students were grouped according to high or low prior knowledge of the content. The researchers reported that:

. . even though each treatment had been deliberately designed and positioned in the instructional sequence to instigate higher levels of information processing, when students were permitted to interact with their respective treatments for equal amounts of time insignificant results in student achievement occurred on the different criterion tests. Results also indicate that different visual enhancement strategies function differentially in reducing prior knowledge (high and low) between students within each group (p. 85).

While computer animation research can be covered in only a few paragraphs here, Reiber (1994) was able to devote an entire chapter to the subject. Considering the recency and thoroughness of his review, his conclusions are the best and latest word on the subject:

• Despite the popularity of animation among CBI designers and developers, little research is available on its effectiveness.
• Although animation can be a dramatic visual effect, research indicates that animation's effects on learning are quite subtle.
• Early animation research was heavily prone to confounding.
• In order for animation to be effective, there must be a need for external visualization of changes to an object over time (motion attribute) and/or in a certain direction (trajectory attribute).
• Children and adults vary in the degree to which they benefit from animated displays.
• Learners may need to be carefully cued to information contained in an animated display.
• Young children seem able to extract information incidentally from animated displays, although they may form misconceptions without proper guidance.
• Animation, as continuous visual feedback, is an important part of visually based simulations, although the role that animation plays in such activities cannot be isolated and studied apart from the activity itself.
• Research indicates that visually based simulations can be effective practice strategies, as compared to traditional questioning activities.
• Visually based simulations have shown to be intrinsically motivating for children in intermediate grades.
• Early research on using visually based simulations as inductive learning strategies indicates that adults are frequently uncomfortable with open-ended, discovery-based activities, especially when they perceive the learning environment to be formal or "school-like" in other ways (p. 169).

16.11.4 Graphic User Interfaces and Graphic Browsers

The graphical user interface (GUI) is changing the way computers are used. Much has been written about it in the trade press and even in a few scholarly works (e.g., Reiber, 1994). However, in spite of the fact that the GUI represents a shift from verbal access to, and verbal manipulation of, computers, no visual literacy research has been reported. Macintosh mavens have heralded the fact that learning new Mac applications is easy because they all share a similar look (share a common visual language). Shneiderman (1987) indicated that students tend to reject the use of computer applications that do not have an interface (appearance) they can understand.

GUI conventions include the use of standardized icons such as the trashcan, folders, a printer graphic, a paint brush, and a magnifying glass. Emerging CBI standards for GUI include general acceptance of right and left arrow buttons that allow students to go to the next frame or to return to the previous one, hooked arrows that let users return to the previous menu, and the ubiquitous question mark that can be clicked for on-screen help. Screen geography (location of elements) is partially standardized. There are drop-down menus and roll-ups that are activated by a mouse-controlled arrow. And each individual program has the potential to be accessed by easily learned "buttons," the key aspect of which is their visual recognizability. While usage has tended to, standardize these conventions, research has not played a significant role.

Limited research has been done on the effectiveness and acceptability of buttons. Egido and Patterson (1988) studied the effects of buttons as browsers. They found that buttons that combined icons and1words were superior to word buttons. In corporate research reported by Microsoft (Temple, Barker & Sloane, 1990), picture buttons (icons) were found by adult users to be preferred to other types of buttons.

Lucas & Tuscher (1993) conducted a study to determine whether adult button preferences applied to adolescents. They found that, like adults, early adolescent students preferred buttons that contained both "Pictures" and words, but that they were more accurate when using word-only buttons.

The button and drag features of the GUI have made possible interactive CBI. Mays, Kibby, and Watson (1988) reported the development and evaluation of hypermedia instruction on the Macintosh that featured learning by browsing. In an experimental study that assessed learning as measured in a posttest, Tripp and Roby (1990) found that induced visual metaphors did not significantly increase learning of foreign-language vocabulary (Japanese). There was functional similarity in their work and that of Mays, Kibby, and Watson (1988) in that the students had visual browsing capability. Jones (1995), whose criticism of current screen design guidelines, was mentioned earlier., has provided seven guidelines of his own for designing screens that facilitate browsing:

1. Provide selectable areas to allow users to access information.
2. Allow users to access information in a user-determined order.
3. Provide maps so that users can find where they are and allow provisions to jump to other information of interest from the map.
4. Provide users with feedback to let them know that they must wait when significant time delays are required for the program to access information.
5. Provide users with information that lets them know that they are making progress.
6. Arrange information in a nonthreatening manner so that users are not overwhelmed by the amount of information contained in a program.
7. Provide visual effects to give users visual feedback that their choices have been made and registered by the program (p. 267).

When the research catches up with the possibilities offered by the technology, these guidelines will have been empirically validated or rejected.