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Non Web-Ready Documents (part II):
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What's Wrong with PowerPoint Documents?
In the May/June 2004 edition of the DE Oracle, we talked about the problems with Microsoft Word documents as non-web ready documents, because of their susceptibility to viruses and other security vulnerabilities, their size, and the proprietary nature of the file format. PowerPoint documents are another file format that often creates problems in the online setting, though sometimes for different reasons. While some have taken issue with the use of PowerPoint in general as a communication tool (notably Ian Parker's article "Absolute Powerpoint" and Edward Tufte's "PowerPoint is Evil"), PowerPoint remains pervasive in business and in higher education. Like most of the components of the Microsoft Office suite, PowerPoint has been vulnerable to virus attacks since at least 1999. While the problem seems to be less acute than those suffered by Word, it exists nonetheless. The usual precautions are recommended here as well -- careful screening of received files, use of a firewall, an up-to-date virus scanner -- but there are no 100% guarantees. Microsoft has a page dedicated to helping prevent infection of PowerPoint files with viruses. Just like with Word, PowerPoint is a proprietary format. Effectively, if you want to work with PowerPoint files, you need to buy PowerPoint. It is true that the package comes as part of the popular Microsoft Office suite of products, but that is likely still far from including your whole audience. Microsoft does make a PowerPoint viewer available for free. People who do not have PowerPoint installed can download this software and view PowerPoint files, but not edit them. This does, however, involve another download and an additional installation of software.
Perhaps the overwhelming concern with regard to PowerPoint files is that they are extremely large. Typical PowerPoint files are megabytes in size. A very modest 25-page presentation with a custom background, mostly text, one graphic slide, and no animation can run over 2 MB. It is not uncommon to see presentations reach 10 or even 25 MB for the more graphically-oriented presentations. In early 2004, WebTycho's statistics showed that a third of its users dialed in to the system at speeds of 56Kbps or less. This means that these users could wait more than 5 minutes for the simple file to download before they could even see it. For the bigger files mentioned, that quickly balloons to more than 25 minutes or a full hour for the graphics-rich presentation. What Are Some Alternatives?Smaller PowerPoint FilesThere are some strategies to reduce the size of files that users have to download. The first, of course, is simply to create plainer presentations that rely more heavily on text and use graphics and other multimedia very sparingly, if at all. This only somewhat mitigates the problem, as shown by the 2 MB example above, and some might argue that reducing a presentation to just text undermines the whole point of using PowerPoint in the first place. But by reducing the file size, it makes the document more accessible for those on slower connections. Your readers will still need a PowerPoint viewer and have to scan the files for viruses, but 2MB is preferable to 10MB. Converting to PDF FilesA better solution is to convert PowerPoint slides to Adobe Portable Document Format files. These PDF files maintain the "look" of the presentation, but are not subject to viruses, and dramatically reduce the file size, even when many graphics images are used. The 2 MB file mentioned above came down to a relatively tiny 174 KB when converted to PDF -- more than a 90% reduction in file size. In addition, the PDF viewer is in widespread use among web users. As mentioned in the previous edition's article, however, there are some drawbacks to using the PDF format, most notably the costs associated with producing the files. Converting your PowerPoint files into PDF files gives the best of benefits to your readers; smaller files, no danger of viruses, and your readers are more likely to have the Adobe PDF viewer at hand than the PowerPoint viewer. However, this alternative does call for more work from the instructor in the beginning. Saving as Web pagesAnother alternative is to save your PowerPoint files as a web page so that they are even more easily viewed by your readers. Different versions of PowerPoint have had the ability to output the slides in a "Web"-friendly format, saving each slide as a graphic image and generating Web pages to hold and navigate among them. However, each version of the software seems to have approached the output differently, and the files are notorious for working poorly on browsers other than Microsoft's own Internet Explorer. This option also requires that you have a place other than WebTycho to upload these files, such as an account on the Polaris server. The DE Oracle does have articles on how to publish PowerPoint presentations in a Web friendly format; Publish a PPT 95/97 Presentation in HTML format, Publish a PPT 2000 Presentation in HTML format, and Convert a PowerPoint Presentation to a Single Webpage. "Streaming" the Slides
Perhaps the best strategy is to have the slides "stream". That is, that a file can start to be played while the information is being transmitted without waiting for the full file to have arrived. This is somewhat akin to driving over a bridge as it is being built in front of you. The advantage is you don't have to wait for the whole file to be downloaded -- or bridge to be built -- before starting to use it. There are several different approaches to streaming PowerPoint presentations. Some simply show reduced images of the slides one after the other. Others allow the user to navigate backwards or forwards through the presentation or to skip to slides wherever they may be within the presentation. More sophisticated solutions allow audio and even video narration to laid over the presentation. Again, the benefit is that no matter how big the file, the material can start to be played without waiting for the whole of it to be downloaded. In general, the presentations are viewed using plug-ins that most users have such as RealPlayer, Windows Media Player, or Flash. Several streaming solutions are available, and a discussion of the relative merits of each is beyond the scope of this article. However, some that we've experimented with include Accordent PresenterONE (free basic version of PresenterONE available for download), Impatica, AuthorGEN, and Microsoft Producer. So, while it's tempting to create material using PowerPoint, or to provide exsting material in that format online, there are some real problems with this, mostly related to the size of the files. Faculty members might consider keeping their presentations simple or converting them to PDF format or HTML. An increasingly popular solution is to "stream" the content by one of several means such that the audience doesn't have to wait for the whole file to be downloaded before they can watch it. URLs of Links Used on This Page
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