distance education conference presenters call for papers reference list

          Streaming Instructional Media Via the WWW: Finally Ready For Prime Time


          Tim H. Murphy, Assistant Professor

          Texas A&M University


              This document is intended as an introduction to the production and distribution of multimedia instructional material using streaming technologies on the World Wide Web (WWW). Successful preparation and distribution of streaming multimedia is now within the reach of many individuals and most organizations.


          It seems everyone is interested in streaming media these days. Many events have recently been broadcast on the Internet though what has come to be called Webcasting. There have been interesting events from the field of medicine, including the birth of a baby (http://www.abcnews. com/sections/living/DailyNews/netmom980610.html), and open heart surgery (http://207.87.15. 72/liveevents/openheart/f_main.htm). NASA generated quite a crowd with the Mars Pathfinder Mission (http://mpfwww.jpl.nasa.gov/). Rock concerts, auto races, and various marketing events, like the launch of Windows 98 have drawn a lot of viewers. Several celebrities, including the actor best known as Captain Kirk, have recently discovered the Internet as yet another outlet for their marketing and personal promotion efforts. More and more, the web is being seen as an additional channel for the broadcast of events captured in digital audio and video.

          According to Multimedia Research Group, Inc. (1998) of Sunnyvale, CA, and Fuji Keizai USA, approximately 4,000 Web sites offered video clips in 1996. That number tripled to 12,000 in 1997 and is expected to triple each year for at least the next three years. While this rate of growth is impressive, those 12,000 sites represent less than 1% of the sites on the Web.

          Three trends are converging that will speed the adoption of these robust forms of multimedia communications on the web. First, compression techniques and algorithms continue to improve, enabling increasing audio and video quality at decreasing bit rates. At the same time, networking technologies are developing at a dramatic pace, with nationwide initiatives like the Next Generation Internet (NGI) and the Internet2 (I2). People involved with these collaborative efforts are predicting bit rates 100 times faster that today’s Internet to be widely available by 2001, with some users experiencing bit rates 1000 times faster (Grush, 1998). Finally, the digital capture and editing of audio, still graphics, and video (cameras, hardware, software, etc) is now within the reach of the mass market, both in terms of price and ease-of-use. The quantity and quality of multimedia created is about to increase dramatically. The convergence of these three trends will create additional capacity for high quality audio and video communications on the Internet, and simultaneously, additional demand.

          Why would educators, trainers, and instructional designers be interested in this technology? Research has shown that methods of communication utilizing multiple sensory channels increase both learning and retention. We simply learn and remember more of what we see and hear than we do of what we read, or see, or hear alone. While computer aided instruction (CAI) has long benefited from this principle (Paden and Barr, 1980), the Web was unable to support the bit rates necessary to enable these kinds of media. Video, and to a lesser extent, audio files were simply too large to transmit via the Web.

          Streaming media technologies promise to extend these multimedia communications channels to the Web. Streaming is a technology that allows the client and server to communicate and determine the amount of buffer needed so that a file can begin playing before it is completely downloaded, and finish downloading as it plays. This method of timing the delivery of data simulates real-time delivery of multimedia. Some of the predictions for the growth and availability of network bandwidth may make this technology may appear to be stopgap in nature, but in the absence of unlimited bandwidth some form of digital compression will always be necessary for the long-distance transmission of audio and video. Software that measures and compensates for the variability in network connections will be necessary well into the future.


          At the time of this writing, both Microsoft and RealNetworks have Webcasting solutions that let you encode a live video stream (with audio) on one PC and hand that stream off to another PC (a media/Web server) for consumption by anyone visiting the site hosted by that Web server. In other words, as long as a user has the proper client software installed correctly, she can come to your site with Netscape Navigator or Internet Explorer 4 and see a live or previously captured audio and or video event embedded in a Web page. All you need to provide these live or archived events to your learners is a video camera, a video capture card, and two PCs--a dedicated capture machine, and a streaming media server/Web server. Figure 1 below is the recommended configuration, but a single machine can serve to encode either live or stored content, and a separate single machine can act as both NetShow and Web server.

          Figure 1: Recommended NetShow Configuration


          Selecting a Development Platform:

          As recently as last year, streaming media was a very complex proposition. There were several companies with competing products all of which provided similar results (Johnson, 1997). Today, users still have to choose a file format, but the formats are distilled to just a couple of major choices. More importantly, the quality of the streaming media products available has significantly improved. The highly fragmented streaming-media market that included products from Vosaic, Xing, Vivo, VDONet, and VXtreme among others in 1997, has matured into a race between Microsoft’s NetShow Services and RealNetworks’ G2 technology (Ozer, 1998).

          From the users’ perspective, it’s an easy choice. There is a rapidly growing body of streaming-media content available using each of these products. Microsoft’s and RealNetworks’ products can both automatically download playback components for new technologies as they emerge. RealNetworks uses this feature to support AVI, WAV, MIDI, and MPEG-1, but not NetShow files. Media Player supports more formats, including files created using RealVideo through version 3.0, but Media Player can’t play RealSystem 5.0 or G2 files. Web surfers should download and install both players since many sites post their media in only one or the other format.

          For a developer, choosing a development platform is a more difficult decision. As I approached this decision, I identified four criteria as important: The availability, reliability, and compatibility of the necessary client technology; the relative quality of the product produced; the probable longevity of the platform; and the cost of the total (client/server) solution.

          The competing firms have adequately addressed the first criterion. Each of the competing products is readily, almost ubiquitously, available. In my testing, when properly installed and configured, both were equally reliable. Neither or the client ‘players’ conflicted with the software installed on the test machine.

          Quality is a difficult construct to measure. Although I perceived some quality advantages, the experts report that the products cannot be differentiated on audio and video quality. "Though one technology may prove superior in limited experiments, tested across a range of video clips and bandwidths both offer equivalent audio and video quality" (Ozer, 1998, p. 36).

          RealNetworks’ recently debuted G2 product introduces Synchronized Multimedia Integration Language (SMIL). SMIL is an XML-based language that defines how to create integrated presentations combining linked text, audio, video, still images, and Flash animations. It also enables pans, zooms, fades, and transitions between these elements. Microsoft supports streaming JPEG images synchronized with audio but without special effects. NetShow’s key strength in this area is the ability to produce streaming content from PowerPoint presentations ‘annotated’ with audio.

          While RealNetworks’ basic audio and video encoders are easier to use than Microsoft’s, RealNetworks has yet to deliver easy-to-use SMIL encoding tools, leaving SMIL content creation the providence of experts. Still, for those developers seeking the most compelling presentation of video at 28.8 Kbps or the integration of diverse forms of streaming media, G2 with SMIL is currently better qualified.

          From a broad field of competitors a year ago, two products remain. Microsoft’s NetShow Services and RealNetworks’ G2 technology. Many people have wasted time and effort creating educational multimedia content that, due to obsolescence of the development platform, is now essentially unusable by the majority of web clients. The probability that media developed using the chosen platform will remain valuable over time is an important consideration. Both of these companies have demonstrated a commitment to the continued advancement of their streaming-media platforms. RealNetwork was an early leader in this field, and maintains a loyal following. There are over 200,000 hours of live content broadcast weekly using RealNetworks software, and more than 31 million players have been downloaded. Microsoft’s popularity is demonstrated by the adoption of the phrase often used in the past to describe hardware purchasing decisions, "No one was ever fired for recommending IBM" has become, "No one was ever fired for recommending Microsoft."

          The advantage in the cost of the total client-server solution clearly belongs to Microsoft. Free is always good--NetShow is free. The client software, Windows Media Player, is free and replaces the Media Player installed with the Windows 9X or NT operating System. The NetShow Tools software, used to create and edit the streaming media files, is free. Even the NetShow server software is free, assuming that you are already running Windows NT Server 4.0. If not, the retail cost of NT Server 4.0 is $385 from beyond.com.

          The RealNetworks solution is not free. The limited client, RealPlayer G2, is free, but the complete client software costs $29. The full-featured content production package, RealProducer G2, costs $149.95.

          Serving media using the RealNetworks products can be costly. The Classroom Server Package, designed and licensed specifically for educational use is $1,895 for 50 concurrent users. You’ll probably want to add free server upgrades and phone support - the first year is $495; subsequent years are $795. It comes with a 50-seat license for the RealPlayer Plus software. If you think you’ll need to support more than 50 concurrent users, RealNetworks has the following options; Internet Solution I, 100 Concurrent Users, $5,995, with support and upgrades at $2,395, total $8,390; Internet Solution II, 200 Concurrent Users, $11,195, with support and upgrades at $4,475, total $15,670; Internet Solution III, 400 Concurrent Users, $21,595, with support and upgrades at $8,635, total $30,230.

          A colleague of mine pointed out that the $29 cost of the RealPlayer Plus is hardly a burden for most web surfers, so I asked him to fund it’s installation on just the 1,200 machines my students typically use. Placed in the context of growing demand and stagnant budgets, even the extremely reasonable cost of the RealPlayer Plus is a significant disadvantage.

          For many Web site developers, and most distance learning content-creation efforts, NetShow’s free tools for streaming audio and video should suffice. It is my opinion that RealNetworks’ current advantages, the ease of use of their encoder and the use of SMIL to coordinate multimedia streaming, are likely to be short-lived. I expect the Microsoft product line to incorporate the most popular of these features within the year. In fact, the beta version of a new product created to address some of these concerns, Windows On-Demand Producer, became available after I finished researching this article (Windows Media, 1998). Using the criteria described here, I chose Microsoft’s NetShow Services.


          Selecting Media:

          Having made the choice, let’s examine the types of streaming media one can create using NetShow Services. While others use more and different classifications, I contend that there are only three basic types of files you can produce using any of these products; Video, Audio, and Synchronized Audio. Video and audio files may be streamed either live, as the event occurs, or from an archived file saved to the NetShow server. The process of creating synchronized audio files makes them suitable only for archived streaming.

          Video files are the newest, and get all the attention. From a basic perspective, video files include both an audio signal and a series of images played back as rapidly as possible. While new compression and decompression (codec) techniques included with streaming technologies make these files much better than was possible even a year ago, with greatly enhanced audio and much better video quality, the resulting video experience is still no where near VHS tape. The typical streaming video is small (160X120), and the frame rate is typically between 8-15 frames per second (fps). While video compression techniques have improved, and we can now make tradeoffs between the clarity of the images displayed and the frame rate, it is the audio quality of these video files has experienced the most dramatic improvement. Software developers have come to realize what many of us already knew. In the complete multimedia experience, audio is often more important than video.

          Audio files have been available longer. They are inherently smaller in size, and compression techniques for audio have been found that work very effectively for each of the different types of audio. A symphony orchestra has more variability and requires a much greater dynamic range than does a single person speaking. Codecs have been developed to address these differences.

          Synchronized Audio files are not really new in concept. I suspect that most of us have experienced an annotated slide show using a 35mm slide projector and a cassette tape. With the advent of client-side processing in web browsers using scripting languages like JAVA or VBScript, these types of media presentations became possible on the web. In effect, an audio file is streamed to a client and embedded in that audio file are commands that cause other types of media to be downloaded and displayed on the client machine. These images or text messages can be embedded in the stream and rendered in the MediaPlayer or they can be "URL flips," or commands that cause an image or html coded page to load to a target frame in the client browser.

          While perhaps not perceived as state of the art, Synchronized Audio files have several attractive characteristics for distance education and training environments. In terms of the necessary bandwidth, illustrated audio presentations are a step up from streaming audio and at least one step below streaming video. If you anticipate that your target audience will have lower bandwidth capabilities and your content will benefit from illustration, then synchronized audio may be a viable solution. Even when you can determine that your learners have access to higher levels of bandwidth, you may choose to use higher-quality, less frequent, still images rather than poorer-quality video. If you remember that a second of broadcast quality video is really a collection of 30 images shown in a rapid sequence, then the question becomes, do you really need all those pictures?

          This is not a rhetorical question. One of the fundamental principles of instructional media design may be obvious, but I think it bears repeating. Each aspect of instructional media (graphics, sound, video) can aid learning, it can be neutral, or it can detract from learning. Although it is very easy to become enamoured with the gee-whiz aspects of motion video at 30 fps, the focus must be its effect on learning. In my experience, and in most of the settings in which it’s employed and evaluated, visual motion by itself has little effect on learning (Reiber, 1994). In some specific cases, such as when the underlying instructional objective includes motion (e.g. Newton’s Laws of Motion), or when used to direct the attention of the learner, putting visuals in motion does contribute to learning and retention. I suggest that you use motion only when you believe it will contribute to your learning objectives, and not just because it’s technologically possible.

          Once you’ve selected an appropriate delivery media for the transmission of your instructional material, it’s time to get the hardware and software configured to create your streaming file.


          Setting up NetShow:

          There are two primary components of NetShow Media Services. NetShow Tools includes the software necessary to create and edit ASF files, and NetShow Server adds a service to Windows NT Server 4.0 that serves, or streams, these ASF files.

          Setting up NetShow Tools: 1. I chose a Windows95 machine to accomplish the encoding function. This happened to be my laptop machine, a Gateway Solo 9100 (PII 266/128MB of RAM). The recommended minimum hardware configuration for Win95 is a P133/32MB RAM. I also installed the software on a Dell Optiplex GX1 (PII 400/192MB of RAM) desktop computer running Windows NT. When not encoding ASF files, these machines do all the others things they’ve normally done.

          2. The laptop shipped with a videocapture card (one of the reasons I chose it). I installed the Microsoft recommended Winnov VO Video Capture Card in the desktop machine. This card is getting very popular in live streaming environments and is giving the other recommended cards (Intel Smart Video Recorder III, Osprey-100) some serious competition at a lower price.

          3. I installed the NetShow Tools software, downloaded from the Microsoft Web site, on both machines. Following this installation, I connected my camcorder to each machine, then ran the encoder from the Start/Programs/NetShow Services/NetShow Encoder menu. In both cases, the Encoder found the video source without incident.

          Configuring the NetShow Server: 1. Select an NT Server 4.0 machine as the NetShow Services box. Win95 does not support the NetShow Server Services. The NT 4.0 server in my office (PII400/128MB of RAM) also had IIS 4 installed and had been running as a Web server. Microsoft recommends running separate machines for these two services (IIS and NetShow), but supports running both on the same machine, and I’ve not experienced and difficulties thus far. I recommend locating the NetShow server and the Encoder machines on the same LAN when possible.

          2. Install the NetShow Services software by executing the NSSEVER.EXE installer, downloaded from the Microsoft Web site. Following the installation, select Start/Programs/NetShow Services/NetShow Administrator.

          3a. If you want to serve archived ASF files, you’re practically finished. Place the encoded ASF files in the proper "root" directory (default is C:\asfroot) and they’re ready.

          3b. If you want to serve or broadcast live ASF streams, there is another step. Create a Broadcast Unicast Publishing Point (easy to do via a NetShow Administrator wizard) linked to your NetShow Encoder machine. This publishing point remains active after you close the NetShow Administrator. The wizard also creates HTML code for use on your Web server. Performing these three basic steps engages the NetShow Services machine in the archived or live Webcasting operation.


          Using NetShow Tools:

          NetShow Services ships with the tools listed in Table 1 below. The NetShow Tools are installed on the machine that takes the audio and video signals, digitizes and compresses them, and provides them to the NetShow Server for distribution. Using these tools, either alone or in combinations, you create and or convert streaming content (NetShow Services, 1998).

          Table 1

          NetShow Tools



NetShow Encoder

Allows you to take an audio or video source, compress it, and either store it to ASF or send it to NetShow Services to distribute the feed.

NetShow T.A.G. Author

Allows you to take still images and audio, and combine them to make an illustrated audio presentation. Can also add markers, URL flips, and Visual Basic® or JavaScript™ events into the stream.

PowerPoint Publish to ASF

The PowerPoint® Publish to ASF add-on allows you to give a PowerPoint presentation into a microphone connected to your PC, and then take the slides and the narration and easily and automatically create a NetShow illustrated audio presentation at the custom bandwidth you specify.

NetShow Indexer

NetShow Indexer utility for cutting Advanced Streaming Format (ASF) files, and editing properties, markers, and script commands.


MS-DOS command-line utility that allows you to take a precompressed AVI or QuickTime (.MOV) clip and convert it directly to ASF.


MS-DOS command-line utility that allows you to take a precompressed WAV audio file and convert it directly to ASF.


          The Encoder is the primary workhorse of the NetShow tools package for creating live ASF streams. Compressing live audio and video in real time is an extraordinarily processor-intensive task. The Encoder should be on your best machine, and should be solely dedicated to this task. No unnecessary services or programs should be running while the Encoder is operating. It’s counter-intuitive to me, but the higher the target data rate, the higher the processor requirements. For example, if you’re encoding live video targeted for 56-Kbps consumption or higher, Microsoft’s recommended machine is a Dual Pentium II 233 MHz or DEC Alpha 533 MHz. The same video source targeted to a 28.8 Kbps stream, the recommended machine is a Pentium 200 MHz. The Encoder always creates an archived file of the live stream, so it can be used to create archived ASF files, but other tools may be more appropriate. When creating archived content, hardware requirements are greatly reduced because the operation no longer need occur in real time.

          The rest of the tools provided are used to create and edit archived files from various sources. The primary workhorse of this team of software products is the T.A.G. Author. To create archived ASF files using the T.A.G. Author you begin by selecting or creating still images and audio files. You then insert these into the T.A.G. Author. You can then sequence the audio and video files, add text and "menu items"—called markers, and insert URL calls to other html pages that will render to a target frame on the same web page as the embedded Media Player.

          The PowerPoint Publish to ASF wizard is the simplest path to creating streaming Synchronized Audio files for those already familiar with PowerPoint. If PowerPoint 97 is already installed on the machine to which you choose to install NetShow Tools, the Publish to ASF command line is added under the Tools menu of the PowerPoint program. You can use the Record Narration command under the Slide Show menu of the PowerPoint program to record audio that will be associated with each slide as you advance through a slide show. After saving this file as a PowerPoint Presentation, you simply select Publish to ASF from the Tools menu and the presentation is encoded to your chosen target bandwidth (e.g. 28.8 modem). Your PowerPoint slides, whether primarily text or graphics, will be synchronized with your audio annotation and ready for streaming to your learner’s Media Player.

          NetShow Indexer allows you to edit, in a very limited way, existing ASF files. You can shorten or cut an ASF file and insert or edit markers or script commands. For the most part, you will not want to consider ASF as a format suitable for editing. To accomplish edits of any real substance, the original, or source materials will need to be saved and recreated using another tool like the T.A.G. Author.

          The VidToAsf and WavToAsf programs are useful for those who already have powerful programs for editing and compressing, respectively, video and audio files. Neither of these programs is intended for the inexperienced multimedia content creator. Properly prepared video and audio files, created in another software program (e.g. Adobe Premiere, SoundForge) can be converted to ASF format using these utilities. While basic, these utilities are powerful. For instance, markers and URL flips can be inserted in the stream, and an external audio file can be used to replace the audio file associated with the .avi video file.

          There are also some third-party tools available that can help speed the processes or provide enhanced functionality. One of the most complete third-party solutions is VivoActive Producer 2.0 for NetShow (Vivo.com, 1998). This $695 product provides a more user-friendly interface to creating NetShow ASF files. The company states that Producer 2.0 for NetShow is your one-stop, total solutions package, and the first and only single application that allows you to generate both live and on-demand streaming media in Microsoft’s ASF file format.

          Before I spent the $695, I’d want to try out the, now available and free, Windows Media On-Demand Producer, co-developed by Microsoft and Sonic Foundry. Microsoft advertises that this product simplifies the creation of streaming media content for both experienced and novice streaming media authors (Windows Media, 1998).

          Before creating your ASF files, you’ll want to consider the how you want them used and displayed by your users. There are several ways to extend the capabilities of ASF files, and more narrowly define the experience of your learners. These features involve advanced HTML coding, and a basic understanding of scripting languages, but their use can greatly enhance the look and function of your multimedia instructional materials.


          Incorporating ASF Files Into Multimedia Webpages:

          ASX Files: You can provide a link directly to your ASF file, or from a link in your Web page to an ASX file stored on your Web server. At its simplest level, an ASX file is a redirector file. It transfers control of the data from the Web browser to the Microsoft Media Player application so that the data can stream. When accessed by the Web browser, it loads Media Player and points it to the location on the streaming server that houses the actual ASF file. The Media player then looks on the streaming server and plays the ASF stream.

          There are several characteristics that recommend the use of these ASX redirector files. One important advantage is that users will not download your ASF file. Your ASF file streams to the Media Player and is displayed, but not saved, on the client machine. This feature has obvious advantages as you think about intellectual property and copyright issues. In addition, using ASX files can help assure the delivery of your ASF media by rolling over delivery to other servers. In the event that network traffic, noise, or other factors keep your ASF file from being properly delivered, then your ASX file can tell the player where to find another copy of the ASF in as many backup locations as you choose. ASX files allow your ASF files to open sooner, without requiring the user to choose between "opening or saving" the file. In cases where the client can't connect using an MMS protocol, they switch to another protocol listed in the ASX file, such as the HTTP protocol. This process ensures that the content reaches the client regardless of certain network problems such as firewalls or high network traffic.

          The ASX file is a simple text file. You can create them in any text editor (e.g. Notepad). The ASX text file must specify; the protocol (either HTTP or MMS), the name of the server, a virtual directory (if necessary), and the name of the ASF file. All four of these variables are typically contained in a single line of code, but the ASX file may contain more. An example of a more complete ASX file could look like this:

              <ASX Version = "3.0" BannerBar = "Fixed">

              <ABSTRACT>This text will show up as a Show Description</ABSTRACT>


              <Ref href = "mms: your.NetShow.server.com/demo.asx>

              <ABSTRACT>This text will show up as a ToolTip</ABSTRACT>

              <TITLE>The title for the ASF stream</TITLE>

              <AUTHOR>The name of the author</AUTHOR>

              <COPYRIGHT>1998 Your Company</COPYRIGHT>

              <MoreInfo href = "http://www.your.web.server.com/index.html>


              <BANNER href = "banner1.jpg"> </BANNER>

              <Logo href = "icon.jpg" Style="mark" />

              <Logo href = "icon.jpg" Style="icon" />


          Embedding the Media Player: There are two main ways to play the ASF file (called by the ASX file). You can have the file play in a stand-alone Media player, or embed the Media player in a Web page. In stand-alone mode the Media player runs as a separate application. You start playing an ASF in stand-alone mode by opening the ASF from the Media player, or you can use a hyperlink in your Web file to trigger the ASF to start playing. An embedded ASF appears in the Media player, which in turn is embedded in a Web page. To embed the player in the Web page so that it can be viewed by all browsers (Internet Explorer, Netscape, and others), use an object tag containing an embed tag and a noembed tag (see sample code below). In the script commands you use to embed the player, you set the property that identifies which ASF (orASX) file to play. By setting parameters within the object and embed tags, you can also dictate what player controls will be displayed and how the player will perform. The following script shows the Media Player control and several of its properties.

              <!-- Object Tag for Internet Explorer -->

              <OBJECT ID="NSPlay" WIDTH=160 HEIGHT=128 CLASSID="CLSID:22d6f312-b0f6-11d0-94ab-0080c74c7e95" CODEBASE="http://www.microsoft.com/NetShow/download/en/nsasfinf.cab#Version=2,0,0,912">

              <PARAM NAME="FileName" VALUE="mms: your.NetShow.server.com/demo.asx ">

              <Embed type="video/x-ms-asf-plugin" src="mms: your.NetShow.server.com/demo.asx "

              filename="mms: your.NetShow.server.com/demo.asx "



              <a href="mms: your.NetShow.server.com/demo.asx ">Start the NetShow Presentation in the stand-alone player.</a>

          How you set the parameters in this ASX file determines how Media Player will work. There are a lot of tricks you can do by manipulating the player control properties. For example, you can make the player transparent, displaying an image (or your logo) in place of the Media Player until an event that you specify occurs. By setting a property, you can play an ASF file automatically when any particular Web page is opened. For more information on setting the player control properties, please see the Windows Media (1998) Web site.

          Using Frames and URL flips: Your ASF file can open up the user's browser and bring up a Web page. With this feature, you can also set up a series of URL flips. These are web pages that load automatically when called by your ASF file. When you're planning your presentation, be aware that any Web pages you call up will also take up bandwidth. Also, URL flips are not precise since you cannot tell how long it will take a browser to download the Web page. You may wish to keep these pages text-based or you might use only pages with small graphic sizes for faster downloads.

          The easiest way to add URLs to your ASF file is using the Microsoft NetShow T.A.G. Author. In the Insert menu, select Add Url. Specify a time for your script command, and type in the complete URL. If you're embedding your ASF file into a framed HTML page, you can have the URLs appear in accompanying frames. Just include the name of your target frame where you want the Web page to appear (e.g. http://www.agdist.edu/index.html&&targetframe). You can include any URL in your ASF file. Media Player does not check, locate, or open the URLs. When Media Player comes to a URL, it sends the URL to the default browser, which then locates and downloads the URL. If the computer playing the ASF file does not contain a browser or cannot access the URL for any other, the URL is ignored and the ASF stream simply continues. URL flips add the ability to include an additional channel for the delivery of text and graphical content in support of your streaming media.



          In reading this introductory document, hopefully you have concluded that successful preparation of streaming multimedia is rooted in precise planning, preparation, systems testing and verification, and an overall understanding of the many variables involved. Few undertakings could be described as more interdisciplinary than the Webcasting of multimedia instructional materials. Of course, the same can be said of many pursuits in Web content development. In addition to content experts and instructional designers, expertise in broadcast production and engineering, telephony, computer systems, and network administration is required. Few individuals hold levels of expertise across such a diverse range of disciplines, so Webcasting is inherently a team effort. Input and expertise will be required from a number of people working together as an instructional development team. Conversely, if this document has convinced you that Webcasting your instructional content is just too big and expensive an effort, then I’ve failed to a large degree.

          I believe that using these techniques you can create more robust communications channels for the delivery of instructional media, creating a more effective learning environment for a more diverse group of learners. Should you choose to adopt these methods as a delivery strategy, you will not be alone. Listed below are a few examples of instructional programs being facilitated and or delivered using these technologies.


          Examples of Streaming Content:

          Cornell University, Dr. Michael Ushay

          Medical School Grand Rounds, delivering physicians' lectures to audiences at 20 hospitals.


          Stanford Online Course, Doug Brutlag

          MIS231 Computational Molecular Biology


          Stanford Online Course, Kevin Rudd

          EE182 Computer Organization and Design


          North Carolina State University, Rick Klevans

          CSC311: Introduction


          Michigan State, Charles Severance

          EGR 124: History of the Internet






              Grush, M. (1998). Raising the bar for networking in education: The next generation internet. Syllabus, 12, (4).

              Johnson, N. (1997). Getting video on the web: Closing in on a moving target. DV Magazine. August. pp. 29-40.

              Multimedia Research Group Inc. (1998). Homepage. <http://www.mrgco.com/> [accessed 11/29/1998].

              NetShow Services. (1998). NetShow Homepage. <http://www.microsoft.com/netshow> [Accessed 9/15/1998].

              Ozer, J. (12/15/1998). Microsoft vs. RealNetworks. PC MAGAZINE. 17, (22). p. 36

              Paden, D. & Barr, M. (1980). Computer assisted instruction in an elementary college economics course. Computers and Education. 4, pp. 259-267.

              Rieber, L. (1994). Computers, graphics, & learning. Dubuque, IA: Brown & Benchmark.

              Vivo.com. (1998). VivoActive Producer 2.0. <http://www.vivo.com/products/prod4ns/jumpns.htm> [Accessed 11/11/1998].

Windows Media. (1998). Windows Media Services Homepage. <http://www.microsoft.com/windows/ windowsmedia/default.asp> [Accessed 11/20/1998].