Visuals

Not all media plug into an electrical outlet. There is a variety of nonprojected media that can make your instruction more realistic and engaging. Pic tures, charts, graphs, posters, and cartoons including those that students themselves produce-can provide powerful visual support to abstract ideas. These nonprojected media can be displayed in a variety of ways. Projected media, such as overhead transparencies and PowerPoint slides, can enhance a presentation made by students or teachers.

NONPROJECTED VISUALS

Nonprojected visuals can translate abstract ideas into a more realistic format. They allow instruction to move down from the level of verbal symbols in Dale's Cone of Experience (see Chapter 1) to a more concrete level.

Nonprojected visuals are easy to use because they do not require any equipment. They are relatively inexpensive. Many can be obtained at little or no cost. They can be used in many ways at all levels of instruction and in all disciplines. You may also use them to stimulate creative expression, such as telling or writing stories or composing poetry You may use all types of nonprojected visuals in testing and evaluation. They are particularly helpful with objectives requiring identification of people, places, or things.

Still Pictures

Still pictures are photographic (or photograph-like) representations of people, places, and things. The still pictures most commonly used in instruction are photo graphs; postcards; illustrations from books, periodicals, and catalogs; and study prints (oversized illustrations commercially prepared to accompany specific instructional units).

Still pictures are two dimensional. You can compen sate for the lack of three-dimensionality by providing a group of pictures showing the same object or scene from several different angles or positions. Also, a series of sequential still pictures can suggest motion.

You may use photographs in a variety of ways. Teacher made or student-made photographs may illustrate and help teach specific lesson topics. Photographs of local ar chitecture, for example, can illustrate a unit on architec tural styles. (In this case, you could reinforce the students' skill in "reading" a visual by pointing out that merely looking at the buildings in our environment is not the same as really "seeing" them.) Photographs taken on field trips can be valuable for classroom followup activities.

Drawings

Drawings, sketches, and diagrams employ the graphic arrangement of lines to represent persons, places, things, and concepts. Drawings are, in general, more finished and representational than sketches (e.g., stick figure compositions), which are likely to lack detail. Di agrams are usually intended to show relationships or to help explain processes, such as how something works or is constructed.

Posters

Posters incorporate visual combinations of images, lines, color, and words. They are intended to catch and hold the viewer's attention at least long enough to communi cate a brief message, usually a persuasive one. To be effective, posters must be colorful and dynamic. They must grab attention and communicate their message quickly. One drawback in using posters is that their mes sage is quickly blunted by familiarity. Consequently, they should not be left on display for too long. Commercial billboards are an example of posters on a very large scale.

Projected Visuals

Projected visuals are defined here as media formats in which still images are enlarged and displayed on a screen. Such projection may be achieved by passing a strong light through transparent film (as in overhead transparencies and slides), magnifying the image through a series of lenses, and casting this image onto a reflective surface. Or, the image can be displayed on a monitor using a doc ument camera. Newer techniques include storing the im ages electronically and projecting them in a digital or analog format such as PowerPoint, Digital storage mech anisms include CD-ROM, the photo CD, digital cam eras, DVD, and the scanner. The most common analog storage medium for visuals is the videodise, or laserdisc (the analog counterpart of CD-ROM and DVD).

DOCUMENT CAMERAS

The document camera is a video camera mounted on a copy stand, pointed downward at documents, flat pic tures, or graphics and small objects (like coins). The im age may be projected onto a large screen within the room or it may be transmitted to distant sites via televi sion. You may place any sort of visual on the stage, and can manipulate the material or write on it, as you would on overhead transparencies. With back lighting you can show overheads or slides.

OVERHEAD PROJECTION

Because of its many virtues, the overhead projection system has become the most widely used audiovisual device in North American classrooms and training sites. The typical overhead projector is a simple device. Basically, it is a box with a large aperture, or "stage," on the top surface. Light from a powerful lamp inside the box is condensed by a special type of lens, pictures and text into a clean visual layout. The visual can be printed directly onto transparency film by a laser printer or onto a paper copy, which you may then use as a master to make xerographic transparencies. Among the types of graphics software available are the following:

• Presentation programs-special software that simplifies creation of slides or transparencies of graphics. that combine text, data, and visuals

• Drawing and paint programs-allow the user to draw geometric shapes and figures; can also incorporate text Charting programs-especially suited to making charts, graphs, and reports from spreadsheet data

• Photo-enhancement programs-allow the manipulation of color and use of special effects to alter photographs and slides 

• Desktop publishing programs-combine features of many other methods to create sophisticated products such as newsletters and books 

There are several technical processes for producing transparencies directly with a computer printer. You need to select the proper type of transparency film for your printer:

• Laser printers print images directly onto special film.

•  Ink-jet printers spray droplets of ink onto specially coated ink-jet film.

• Thermal transfer printers use heat to imprint images onto thermal film.

• Pen plotters draw with pens directly onto specially coated film.

• Impact printers press the ink from ribbons onto impact film.

SLIDES

The term slide refers to a small-format photographic transparency individually mounted for one-at-a-time projection. The standard size of slides is 2 by 2 inches (5) by 5 centimeters) measured by the outer dimensions of the slide mount. When 35mm and other popular types of slide film are sent out to be processed, they are mounted in 2-by-2-inch frames. The actual dimensions of the im age itself will vary with the type of film and camera.

DIGITAL IMAGES

It is possible to store images in a digital (or analog) form and show them on a computer or television monitor or project them before a group. Available digital storage me dia include CD-ROM, photo CD, DVD-ROM, and computer disks. Videodiscs (or laser discs) look similar but store the images in an analog format.

CD-ROM

CD-ROM (compact disc-read-only memory) has the capacity to handle not only quality sound but also large quantities of text and visuals. CD-ROM is a storage sys tem that utilizes a compact, rugged, and lightweight disc only 12 centimeters (4.72 inches) in diameter. It is an optical storage medium that uses a tiny laser beam to retrieve the information on the disc. CD-ROM discs are "read only," which means that the user cannot change or modify the information on the disc. Recordable and rewriteable compact discs are available. Students can create their own CD-ROMs. One suggestion might be for students to produce their portfolio materials on a CD-ROM because the storage capacity and ease of ac Icess to the information makes this a very valuable way for students to store that information.

Photo CD

The photo CD (photographic compact dise) unlizes digital technology to store photographic images. For only a few dollars you can have your photographs, from a regular camera, developed and placed on a compact disc. You can show the photographs on the photo CD using a special photo CD player and display them on a television set, or using your computer you can project them for a group as described in the next section. You can alter the sequence of visuals and create a "slide show" effect with your photographs.

DVD-ROM

Similar to the CD-ROM, DVD-ROM (Digital videodisc-read-only memory) is also a digital storage for mat, but with greater capacity. DVD-ROM is an ideal medium for text, visuals, animation, motion video, and au dio formats that have large storage requirements. Like CD-ROM, DVD-ROM is a storage system that utilizes a compact, rugged, and lightweight disc only 12 centimeters. (4.72 inches) in diameter. It is an optical storage medium that uses a tiny laser beam to retrieve the information on the disc. DVD-ROM discs are "read only," which means that the user cannot change or modify the information on the disc. Recordable and rewriteable DVD discs are avail able, but are expensive. DVD-ROM is only beginning to have an impact in education. In time, however, because of the ability to hold extensive quantities of data, DVD-ROM will replace CD-ROM. Many models of computers are now being produced with DVD/CD-ROM drives.

Digital Camera

Instead of storing the visuals on photographic film, dig ital cameras connect directly to a computer to place the image onto the computer (Figure 6.17). Others store the images directly onto a computer disk or a small dig ital "flash memory" card, or "smart card," inside the camera. These disks and "smart cards" have increased storage capacities, often megabytes of capacity, allowing you to store hundreds of images on one card. Once the picture is taken, it is easy to connect the camera or use the disk or smart card (which does require a special in put device) to put the image onto the computer.

These images can be used in many different ways. You can connect the computer to show the visuals on the monitor, and may in turn connect the computer to an LCD panel or a data projector (see page 164) for group viewing. You can use the images as part of other documents, such as newsletters or word processed pa pers. These images can also be incorporated into Web pages. Because they are digital, the images are easy to place into these types of files.

It is also possible to use software programs, such as Photoshop, to alter the images in ways that enhance or improve their quality or the nature of the image.

Stills from Videotape or Videodisc

Videodiscs resemble silver, shiny phonograph records. They are also referred to as laser discs. Recorded images and sound are stored on these discs in analog format. Each side of a videodisc can hold up to 30 minutes of motion video images, or up to 54,000 still images, or a mix of both. As with digital formats, many videodises are indexed for rapid location of any part of the program material. When a videodisc playback unit is connected to a computer, the information on the disc can become an integral part of a computer-assisted instructional program.

DIGITAL IMAGE PROJECTION

Digital (and analog) images can be shown to individu als using a computer monitor. For showing these images. to a group, you can use a large television monitor (see Chapter 8 for size guidelines), an LCD panel on an overhead projector, or a data projector.

Designed for use with presentation graphics soft ware, liquid crystal display (LCD) projection panels project computer images onto a screen-the electronic equivalent of an overhead transparency. An LCD panel is plugged into a computer and placed onto the stage of a high-intensity overhead projector (but not the table top reflective type). The overhead projector light shines through the LCD panel, projecting the image on a screen. Directions for this process are given in "How to... Operate an LCD Panel."