Audiovisual Materials Used in the Past

• Two of the most traditional audiovisual materials are films and filmstrips. While films are still used in the classroom setting, filmstrips are almost unheard of these days. A filmstrip is a series of still images projected onto a screen, accompanied by a recorded narration. A beeping noise on the narration tells the person controlling the filmstrip when to advance to the next image. More advanced filmstrip projectors automatically advance themselves.
  
  Traditionally, films for educational use were displayed using a two-reel film projector, not a DVD player. For decades it was standard practice in teacher's college to learn how to thread a film projector. Few K-12 schools in the United States still have a film projector on hand.
  
  

Audiovisual Materials in Common Use Now

• Today's teachers still show films in class, but it has become more common to use a DVD player. In many classes a separate player is no longer even needed, as up-to-date computers have DVD drives. To use a computer to play a DVD for the class, a computer projector is required, but many classrooms are increasingly equipped with this latest forms of audiovisual equipment.
  
  Some classrooms still use television sets instead of a projected image. Some teachers still use VHS video casettes to show movies on TV sets, but DVDs are more common; most new instructional videos aren't released on VHS any longer.
  
  

The Digital Revolution

• Audiovisual materials now often take the form of a computer file that is played using software installed on the teacher's computer. Instead of purchasing a DVD to use in classes, schools sometimes now subscribe to digital video services such as United Streaming, available through Discovery Education. These services provide Internet access to tens of thousands of videos, far more than any single teacher could hope to amass in a classroom collection. Access is immediate; there is no need to wait for items to be shipped.
  
  Subscription video services allow teachers to download videos for permanent storage on school computers and also permit videos to be streamed through the Internet. These services have significant additional benefits. They often offer coordinating materials for videos, such as tests, worksheets and teacher's guides, which teachers can download for immediate access. They also have divided long videos into logical segments, making it possible to download just one portion to show. In addition, they include other audiovisual materials besides video. Most services also include audio clips and still photographs, all in downloadable digital format.
  
  

Best Practices for Audiovisual Materials

• Although audiovisual materials can help make the classroom a more lively and engaging instructional environment, they are most effective when used with care. Best practices for teachers include following some basic guidelines, including not showing an entire film or video unless all portions of it are relevant. Teachers should show only the sections that relate to the learning objectives they have established for their students. Teachers should also preview all video material completely. Even instructional videos can contain graphic images that are not appropriate for certain grade levels. No teacher wants to see these for the first time when students are present. Finally, if your school's Internet connection is unreliable, it pays to download digital content in advance instead of streaming it. You are less likely to have an interrupted lesson if you play the content from a local computer.