Using Audio / Visual Aids in the Classroom
By: June Paynter
Your students are used to a very high standard of presentation from the communication they see in the rest of their lives. Magazines, film and television use graphic and communication devices of enormous sophistication. You don’t have to compete with these, but student exposure to them raises the bar for you. Make sure all of your visual aids are professional quality and relevant to the lesson. This will ensure enthusiastic learning in your classroom.
The best audio/visual aids won’t rescue a lesson that is poorly planned and short of student activities, so this is the place to invest the greatest time and emphasis. When the lesson plan is perfected, begin considering the media you will use to enhance the lesson. Consider what equipment choices are available to you, how comfortable are you with the technology, and which equipment/aids best suit the lesson.
The good news for educators and school technology managers is that audio/visual equipment is widely available, and prices continue to drop. This permits many schools to purchase multiple pieces of equipment, reducing the need to reserve and share. It is still possible to overspend for features you won’t use or under-spend, thereby missing vital features.
Here is what to look for in each category of classroom audio/visual equipment.
Higher lumens mean a brighter image—2000 to 4000 lumens are recommended for classrooms (higher lumens for large room and auditoriums).
Open heads allow adjustment of images; closed heads offer better protection if the projector is being moved.
Singlet, doublet and triplet style lenses are available. Singlet is the most basic. Image improves with higher quantity.
Lamp changers allow you to change a burned-out lamp without interrupting your presentation.
DLP Display uses hundreds of thousands of tiny, spinning mirrors to reflect images. Many feel it is the most accurate reproduction of color and images available today.
LCD Display features liquid crystals that realign under electrical stimulation. These displays are slim, lightweight and ideal for TV displays.
Resolution refers to the number of pixels and concentration in a portion of the image. Higher resolution reproduces more image detail and a broader range of light and dark.
More lumens provide a brighter picture, which translates to larger images that look good even in light.
Keystone correction fixes the distortion of an image projected on a wall or screen.
Digital Comb Filter ensures maximum picture detail and resolution. Dynamic noise reduction reduces picture graininess to produce a clearer picture.
Component video inputs best possible input for high resolution sources such as DVD; superb color purity, detail and reduced color “noise” surpass even S-video.
S-video input is the ideal way to connect high resolution picture sources like DVD, digital satellite and cable TV, even better detail than standard video inputs.
Progressive Cinema Scan achieves exceptionally faithful movie reproduction through a sophisticated analog-to-digital conversion.
High Contrast Picture Tube increases contrast under bright room conditions and provides vivid color highlights
Video stabilization helps remove the bumps and jogs from film so you see clear, uninterrupted action.
MegaPixel captures professional-looking still images with excellent picture clarity and true-to-life color reproduction.
Optical Zoon Lens frames shots for better digital pictures by bringing distant subjects closer and pulling back for wide shots.
If you will want to enlarge photos from your camera, be sure that you purchase a unit that has enough pixels to minimize photo degradation at larger sizes.
These boards combine a PC with a markerboard, allowing the teacher to control a computer presentation by touching the board surface with an electronic pen. The teacher stays in front of the class maintaining class interest and increasing participation. They can be attached to PCs via USB cable or can be used in wireless applications. They can be stand or wall mounted. They can be connected to printers so that teacher notes can be printed off and shared with students. They are wonderful for including student ideas during class interaction on a topic. There are several large manufacturers who offer these products.
If you elect to purchase a screen (rather than project onto a whiteboard or wall), be sure the screen size is appropriate.
The screen height should be approximately equal to one-sixth of the distance from the screen to the last row of seats. This allows text to be read and detail to be seen on the projected image.
The first row of seats should be approximately two screen heights away.
The bottom of the screen should be four feet above the audience floor, allowing those in the back to see.
Schools may decide to mount all TVs and TV Combinations or use A/V carts to be able to move the units around safely. Whichever you decide, make sure that you use the manufacturers’ specifications to select the appropriate size and design for your application. High-quality A/V carts are carefully engineered for safety. They have broad bases, strong materials and wire management to accommodate TVs. Both mounts and carts have safety belts and retaining lips to lessen the chances of heavy equipment falling and causing injury. Never move this equipment on booktrucks or standard office carts; they are not designed to safely move the weight.
Always purchase your audio/visual equipment from reputable and knowledgeable sources. Any supplier should be able to match the model and its features to your application. They should be able to explain, in plain English, what the purpose of each feature is and justify why you need it.
Always pre-test your equipment before class starts. Arriving a few minutes early allows you to “dry run” to make sure everything is operational. If it is not functioning, this provides time to get the tech expert to assist you. Make sure you understand how to use the remote for your equipment and laser pointers or other accessories.
Whether you have many A/V resources or just a few, it can be tempting to embellish every lesson with A/V aids. Remember that selective, relevant use of aids will enhance learning, while too many may distract students from the course material.
The prime rule in all public speaking (including teaching) is to tailor to your audience. What medium will give the most impact to the central idea of this particular lesson? The best instructors dramatize an idea or concept by using A/V media. Visual learners will find a concept becomes more memorable and instructive when supported by a clip from a current film. (Copyright laws exempt face-to-face educational environments from infringement penalties.) Sometimes an appropriate cartoon or illustration from print media will cement the idea for students who learn from pictures. Follow the clip, cartoon or illustration with a few bullets that reinforce the idea for students who learn better by reading words.
Look beyond the “usual” A/V aids. A historical era can be brought to life by including CDs of the era’s music or exhibits of period clothes and tools. Geography is more than maps when animals from the region can be brought to class from the local zoo.
Educating children is very important work. To keep them inspired, you need many tools in your kit. Audio/visual aids are all around us and, when used creatively, really make learning fun.
June Paynter is business development manager for DEMCO, Inc., www.demco.com.