In most classroom, we observe CTS classroom standards.
The items described below are general guidelines for technology used in the Faculty of Arts and Sciences classrooms. Each classroom is designed to accommodate the pedagogical needs of professors and classes, which meet in that room. All rooms are designed with the understanding that technology will change regularly during the lifetime of the classroom.
While a review of Title II of the American with Disabilities Act is required for all classroom projects regarding accommodations for individuals with disabilities, Section 504 of the Rehabilitation Act also requires attention. The Office for Civil Rights in the U.S. Department of Education oversees adherence to Section 504 at institutions that receive funding from the Department. Section 504 states, in part:
“A recipient [institution]…shall take such steps as are necessary to ensure that no handicapped student is denied the benefits of, excluded from participation in, or otherwise subjected to discrimination under the education program or activity operated by the recipient because of the absence of educational auxiliary aids for students with impaired sensory, manual, or speaking skills.”
Assistive Listening Systems (ALS)
We install infrared assistive listening systems in FAS classrooms, and we no longer install radio-signal (FM) ALS units. These systems allow users to move from one location to another equipped with an infrared system without the need to acquire a new headset on a different frequency. Infrared and FM systems are not compatible. Induction loop (t-coil) units are not currently used on campus. ALS systems are installed in classrooms with more than 12 seats and when a full equipment package in a room is replaced.
We have portable systems for smaller rooms.
Many hearing-impaired students are now using Bluetooth devices. Some hearing aid manufacturers offer adapters that allow us to interface our existing ALS systems to Bluetooth.
Classrooms have numerous audio concerns including voice-reinforcement, playback, recording, microphones, inputs, outputs, speaker locations, and mixing of multiple microphones. Small and some medium-sized classrooms require playback ("program") capabilities for audio, video, and computer programs. Two speakers on the front walls near the screen(s) are normally sufficient in such classrooms.
Mono systems, rather than stereo systems, are often preferred due to seating arrangement and room design factors. Many rooms have large screens for dual projection or two side-by- side screens, causing the loudspeakers to be mounted a far distance apart from each other. This placement does not allow many students in the front rows to hear both channels of stereo sound. Stereo systems are appropriate for rooms with single image screens and narrow to average room width dimensions. If a wide room occasionally requires a stereo system, such a system can be installed with a mono/stereo switcher. For example, film study courses often require true-stereo or surround-sound.
In medium-to-large rooms, playback and voice-reinforcement are required. A distributed sound system -- a series of small ceiling-mounted speakers evenly distributed -- evenly distributes sound more naturally through the room and providing ± 3 db at every seat. Large wall-mounted speakers near the screen provide playback sound for pre-recorded materials; sound can also be "feathered" to the distributed speakers.
Care must be taken to balance the overall maximum volume of both speech and program audio, so that sound volumes never exceed OSHA standards.
A jack plate, off-centered on the front wall, should include at least four mic-level XLR inputs, line-level inputs, and two outputs; larger rooms require additional inputs. An audio output jack(s) is installed on the rear wall or other appropriate location for video recordings.
A variety of microphones are required to meet various teaching styles. A podium-mounted microphone is suitable for formal lectures. Such units offer hands-free teaching and they are highly reliable. Instructors who do not teach in a stationary position require a lavaliere microphone or a wireless microphone system. In many locations, a diversity wireless system is required as it provides two antennae. By feeding the stronger of the two RF signals to the sound components, this dual system reduces the possibility of dead spots or dropout zones interfering with voice reinforcement. Omni-directional microphones offer greater mobility--that is, instructors may turn their head in any direction and stay within the microphone's reception area--than unidirectional (cardioid) microphones, but they encounter higher occurrences of feedback when an instructor walks within close proximity to voice reinforce loudspeakers. Hand-held wireless microphones should be used in medium to large classrooms when student participation requires amplification, such as, Q & A activities. Catchbox (“throwable” wireless) microphones are used in some lecture halls when student participation is a regular feature of a course.
All items installed in an equipment rack should be covered (installed) with security screws.
Small and some medium-sized classrooms require "program" capabilities for audio, video, and computer programs. Two speakers on the front walls near the screen(s) are normally sufficient in such classrooms.
In medium-to-large rooms, program and voice-reinforcement are required and a distributed sound system evenly distributes sound throughout a room. Wall-mounted speakers near the screen provide program sound for pre-recorded materials.
A podium-mounted microphone is suitable for formal lectures. Instructors who do not teach in a stationary position prefer a lavaliere microphone or a wireless microphone system. Hand-held wireless microphones are used in medium to large classrooms when student participation requires amplification.
Computers in Classrooms
In general, instructors will have the best experience teaching in the classroom when their own laptop is connected to the interface(s) provided. A computer, however, may be installed to serve particular needs.
Classroom computers should always be installed in an instructor accessible location, so they have access to the front panel for the power button, USB ports, optical drive, etc. In a 19U rack, this would be at or near the topmost rack units. Instead of a rack, computers may be installed inside a lectern; this is often preferable, particularly when media controller interfaces are also installed in the lectern. Securing the computer with a security bracket on a rack shelf is preferred but a “Kensington lock” security cable in absence of a shelf is an alternative. The computer should have a dedicated wired network jack in addition to networked media devices and any jacks for instructor and student devices.
The make and model should be a current Harvard “workhorse” configuration in a small form factor (SFF) case. We do not currently support Apple computers installed in classrooms, except in art classrooms. Apple computers cannot be ghost-imaged and if they are accidently turned off, they must physically be turned back on.
A monitor for the installed computer that can “mirror” what is projected is highly preferred, as are USB keyboards and mice. If the computer is installed in a rack and there is a sturdy lectern or desk, the monitor should be installed on that furniture, connected to the digital switcher via a scaling receiver and the keyboard and mouse to the computer via a USB extender. Monitors should be on a highly adjustable VESA arm mount attached to the lectern or desk. Smaller monitors (no more than 22” diagonal, 1920x1080 resolution) are preferred to minimize obstruction. If the projected image aspect ratio and/or resolution do not match, on the monitor it should be scaled to fill the monitor screen.
In rooms lacking a suitable place to install a monitor, the instructor must use the projected image to control the computer and a wireless keyboard and mouse. Wireless input devices are less reliable and require support, even in small rooms their range can be inadequate and USB receiver placement must balance reception and security.
There are many situations in which a moveable lectern is desirable, but these lecterns can cause technical difficulties, such as damaged connectors due to frequent connecting and reconnecting, and limit functions due to wireless operations restrictions. In rooms where a large variety of functions occur, wireless controls can be used.
Lecterns should include a dimmable light that is shielded from the audience; a work area large enough for a laptop computer and papers; an electric height adjustment; and a shock-mounted gooseneck microphone. An electric height adjustment feature accommodates professors of various heights and it allows nearsighted professors to bring materials closer to their eyes. If video recordings will occur, a light-colored top should be used so that light is reflected onto the instructor's face.
The lectern should also be secured to the floor, so that the connectors cannot be pulled out of the floor box by accident. There is a growing trend to install teaching stations that are more of a height-adjustable worktable, rather than a classical lectern.
Although legacy equipment instruments, except for a rare overhead projector, are not installed in classrooms, 16mm film, slide, glass lantern slide, record players, DAT, CD/Cassette, and overhead projectors are available upon request.
35mm film projectors are only available in the Carpenter Center Cinema.
Light switches or controls should be located near the entrance to the room, at the instructor’s station and, where applicable, at the technician’s station. These controls should feature clearly labeled presets (full Illumination, note-taking, etc.). When appropriate, the lighting control should be integrated into the media equipment’s control system, so that the lights will automatically adjust when the projector is turned on or off.
There should be a separate switch to control any light that reflects onto a projection screen, so that those lights may be turned off while other lights are used while projecting images.
Projectors and Flat-Screen Displays
Factors for selecting a video/data projector include required resolution, image size, opacity of window treatments, fan noise level, and ANSI lumen output. All video/data projectors must “multi-sync” to all computers. The minimum lumen output for a standard classroom is 5,000 to 7,000; 8,000-12,000 lumens for lecture halls; and higher lumen output for the largest learning spaces on campus. The native resolution should be a minimum of WUXGA (1920 x 1200) with the ability to compress higher resolutions. Contrast ratio shall exceed 1,000 to one.
Projectors with a lens-shift feature provide some flexibility in installations. Many rooms have obstacles, such as low-hanging lights, that can block a portion of the projected image and lens-shift may provide sufficient adjustments to work in such classrooms. Another consideration is fan noise level, especially in rooms with multiple machines. Projectors with high lumen output lamps require greater cooling, so they produce higher noise levels and some models should be placed in a projection booth or other construction, such as a projector hush box, to reduce noise.
Flat screen displays mounted on a wall or from a ceiling are acceptable for video and data in rooms with up to 30 students. Such displays should not protrude more than 4” from a wall (ADA 4.4.2 Protruding Objects requires 80" minimum clearance for objects protruding 4" or more into an accessible route). Sound bars or external speakers should be included with the installation as built-in speakers do not provide adequate sound playback quality. If the display is wall-mounted, a 5-degree tilt is necessary to reduce glare. Displays should be commercial grade and they should be compatible with security devices.
Flat screen displays are replacing projectors in conference rooms and small classrooms due to lower costs. Before installing a flat screen, a classroom should be reviewed for the amount of potential glare on the display. Although some displays are available with anti-glare screens and they should be used in rooms where display glare will interfere with viewing, such options make the image appear to be of lower nits.
In addition, many of our flat panel installations include a USB camera/microphone package, so that users can use a soft codec, such as Zoom, for video conferencing. This is especially true in the areas of teaching languages.
Almost all of the industrial flat panel displays are now 4k. Several of our faculty members are beginning to present content in 4k and especially in Egyptology and Brain Science.
A compliment of user dongles (laptop interface adapters) shall be provided in every learning space where display equipment is installed.
The bottom of a screen should stop no lower than 40” AFF. Screens in very large rooms and those that lack tiered or sloped seating are installed at higher levels. The top half of the screen should not create a vertical viewing angle of more than 35 degrees. Horizontal viewing angles should be within 45 degrees of the center.
We seek a 4:1 ratio whenever room dimensions allow. In such rooms, the screen viewing area should be a minimum of one foot high for every four feet of viewing distance from the screen in rooms. This ratio is preferred in rooms using only data projection because the fonts on many web sites and in some instructor-prepared programs are of insufficient size to be viewed in classrooms. A ratio of 5:1 is acceptable in most classrooms when a 4:1 ratio is not possible. A ratio 6:1 is the smallest allowable ratio and it is only used when room dimensions cannot accommodate a larger size. In standard classrooms, we do not use screens offering gain of more than 1.1. In rooms with wide viewing angles and high ambient light we consider specialized screens, such as, the current Draper TecVision XH series with 1.0 or .9 gain.
Installing more than one screen in a classroom is appropriate for some applications. With a three-screen arrangement, the center screen is used for single projection, the two side-by-side screens are used for dual projection, and one side screen is used when a projector and chalkboard are used simultaneously. A two-screen arrangement of one center and one side screen--which might overlap—may be preferred in classrooms where instructors do not use dual images but use projected images and a chalkboard simultaneously.
Small classrooms with wall screens under seven feet wide can use manual pull-down units with controlled return. Larger applications should use motorized screens. Due to safety and tripping concerns, we do not use tripod screens. larger than seven feet wide. When using tab-tension screens, we use only the latest models with welded tabs.
Whiteboards should NEVER be used as a display surface, especially with high lumen output projectors. They produce a large area of bright reflection that diminishes the quality of the projected image and it is distracting to viewers. Moreover, the bright spots are known to trigger migraine headaches in some individuals and, when flashing images appear in the bright spot, as a trigger for those who experience seizures. Some recent models offer low glare viewing, but they still have a low level of projection glare.
Student seats should include a writing surface of no less than 150 square inches. In rooms utilizing tablet arms, approximately 10% should accommodate left-handed students. In an institution as diverse as Harvard, seating areas should accommodate 5th percentile females (105 pounds, 5’) to 95th percentile males (215 pounds, 6’2”). These standards should be used to determine clearance areas, sight lines, seat dimensions, and controls.
Whiteboards and Chalkboards
While it is generally stated and especially in math and some science courses, that no room has too much chalkboard space, several factors should be considered. In long lecture halls, chalkboard writing is not legible to students in the back rows, so a document camera should replace chalkboard writings. The bottom of a chalkboard must be at least 40” AFF. Chalkboards on sidewalls often cause more neck strain than learning. A more convenient approach to multiple sidewall chalkboards is the vertical sliding bi-or tri-panel arrangement. Such systems are available in manual and motorized models and they provide the ability to write on several boards that stay within easy view of students. Chalk dust can cause problems for machinery. White boards can solve this problem in many rooms, but some individuals find marker scent objectionable.
There are generally three levels of whiteboards. The low-end melamine board has low gloss and it functions well, but it quickly becomes unusable due to clouding or ghosting. The medium level--some call it "total erase"--is similar to the low level but it has a clear coating that provides a significantly longer life. A final coating is usually applied once the unit is installed. If this final application is not properly applied, the board will cloud. Many medium-grade units have a steel backing. The high-grade unit, sometimes called porcelain finish, is glossy. It is more expensive, but it is the best long-term choice for most classrooms and it is more durable than the other grades.
See the screen section regarding whiteboards and projection.
The ideal window treatment includes two options: opaque and filtering. Window filters sufficiently reduce the amount of sunlight that reflects in a classroom. Because windows are hard surfaces, window filters can also provide some acoustical treatment. Many southern exposure classrooms, film studies, and art courses require opaque window treatments.