The traditional classroom lecture, supplemented with blackboard and chalk, has stood for centuries as the prevailing model for formal instruction. The term "lecture" is based on the Latin lectura, meaning "a reading," and classroom design has traditionally reflected the format where lecturers read from texts or notes held before them on a lectern. Educational institutions are now replacing blackboards and lecterns with hardware and software solutions that provide rich multimedia support for instructional presentations and help engage students in active learning experiences.
Early attempts to supplement the classroom lecture experience involved adding equipment such as 16mm film and 35mm slide projectors to allow students to view previously prepared images. The film projectors were difficult to run, often requiring an equipment operator and the purchase or rental of expensive films, but had the advantage of offering high quality images and sound. Similarly, 35mm slides were difficult and time-consuming to create, but offered excellent viewing quality.
The technology that had the greatest impact in the classroom from the 1950s through the 1990s was borrowed from the bowling alley—the overhead projector. The overhead projector allowed the instructor to prepare a presentation in advance, print it on clear transparencies, and project it onto a screen. More importantly, it allowed the instructor to be spontaneous and write notes, draw illustrations, or scribble equations with a grease pencil and save them for future classes. The overhead projector became, and still is in many places, an indispensable classroom aid, particularly in large classrooms where the chalkboard cannot be seen from a distance.
Large classrooms present other problems as well, particularly with audio. Program audio from films, audiotapes, and videocassettes must be amplified and broadcast over a system of speakers. Typically, instructors in large lecture halls must have their voices amplified through audio reinforcement, captured by a microphone. Wireless lavaliere microphones free instructors from the confines of the lectern and allow them to walk around the room while their voices are still picked up by the audio system.
With the advent of videocassette recorders (VCRs), videotapes replaced films in the classroom except in special circumstances requiring large, high quality displays. The video display unit was typically a standard television monitor, heavy and limited in size, but with the advantage of being viewable in normally lit rooms. Some institutions experimented with video distribution networks that allowed video to be distributed from a centralized source, such as a media center, to the classroom, using fiber optic cable. As VCRs reached commodity prices, however, most institutions found it more cost-effective to build individual VCRs and monitors into classrooms. Some institutions combine the two forms of technology. This allows for centralized distribution of announcements or special presentations, as well as for classroom-level use and control of videotaped material.
When microcomputers became popular, instructors sought the ability to display the contents of their computer screens to the entire class. In the 1980s, liquid crystal display (LCD) units became available that could be placed on top of overhead projectors, building on existing infrastructure the foundation or permanent installation necessary for a structure or system to operate. Although early models had limited screen resolution and required the room to be darkened, making it difficult for students to take notes, this new capability provided instructors with several clear advantages. It reduced the need for preparing overhead transparencies and allowed live demonstrations of computer-related content. The wide availability of network access further increased their value.
By the end of the twentieth century, LCD projection technology had evolved to allow a single projector to display both data and video material adequately. By 2001 projectors could output in excess of 4,000 lumens , sufficient for viewing under normal classroom lighting conditions. The wide availability of quality display technology now allows virtually all material to be viewed digitally in many schools and institutions.
Components of the Electronic Classroom
Today's general-purpose electronic classrooms, sometimes referred to as "smart" classrooms, typically provide at least one LCD data/video projector and offer the ability to connect to a wide range of source input devices, including built-in or portable microcomputers equipped with network communications ports, videocassette recorders, DVD (digital video disc) and/or laser disc players, audiocassette decks, and document cameras. The document camera digitizes two-and three-dimensional objects placed on its stand and displays an image via an LCD projector. This setup provides all of the functionality associated with the old overhead projectors and also allows the digitized images to be transmitted to remote sites or recorded.
Smaller classrooms can utilize a touch-sensitive display panel, such as Smart Technologies' SmartBoard, that acts as either a rear or front projector screen and allows the instructor to make annotations on a presentation or create new images spontaneously. These images can be retained for subsequent printing, posted to a class web page, or edited for future use. The end result provides the instructor with virtually unlimited whiteboard space and an electronic recording of the class displays.
In the classroom, as in most other areas, necessity often proves to be the mother of invention. Innovators at the University of Pittsburgh combined technologies to address two related problems: allowing instructors who use wheelchairs to make use of SmartBoard-like capabilities and providing a means for students in large lecture halls to view the instructors' ad hoc notes, drawings, and illustrations. The solution pairs a small, touch-sensitive LCD panel with a laptop computer and an LCD projector. The LCD panel doubles as graphics tablet and preview screen, allowing the instructor to stand or sit, facing the class, and make drawings and annotations that the entire class can view on the large projection screen.
The needs of some academic disciplines often require more specialized classroom designs, including:
- Electronic tally systems, providing hardware and/or software solutions to allow the class to respond electronically to the instructor's questions and view the results on the classroom display equipment.
- Computers at every seat, or ports and power outlets to allow the connection of networked laptops. Many institutions are moving to wireless networks to accomplish this goal.
- Hardware or software to network the monitors, keyboards, and mouse inputs from the classroom microcomputers. This setup allows the instructor, from the console, to redirect and control any individual computer display so the entire class can see the example.
- Interactive Television (ITV) capabilities, which use video compression algorithms to create two-way audio, video, and data interactions between similarly equipped classrooms. Such facilities use Integrated Services Digital Network (ISDN), Asynchronous Transfer Mode (ATM), or other high-bandwidth network connections to provide real-time support for distance education programs between the instructor and students at one or more remote sites.
Classroom technology continues to evolve at a rapid pace. For example, networked LCD projectors can now display content stored in web pages, allowing an instructor to make presentations without having a local microcomputer. Tomorrow's classroom will be an exciting place for learning with and about technology.
see also Distance Learning; E-books; Educational Software; Telecommunications.
Nicholas C. Laudato
Neff, Raymond K. The Classroom of the Future, Realizing the Potential of Information Resources: Information, Technology, and Services. Proceedings of the 1995 CAUSE Annual Conference, 1995. <http://www.educause.edu/ir/library/text/CNC9548.txt>