Introduction to Untangling the Web

Not too long ago, the World Wide Web was used to display documents. Those documents contained an occasional picture or included the sound of Socks the cat meowing - and we all thought that was pretty amazing. Today things have changed. Quite dramatically! Dazzling multi-media is now common on the web. Every day it seems that some new undreamed of service or technological breakthrough appears on the web. Usually for free.

Do you want your name in lights on Broadway in New York City? You can do that free on the web.

Are you challenged by crossword puzzles? There are special plugins that turn your web browser into an interactive puzzle solver. Would you like to wander around Washington DC or through buildings that are still just architectural dreams?

Virtual reality sites, bubble viewers, and hemispherical cameras abound on the web to let you do that. Do you need to find something in a scholarly journal?

The JSTOR project lets you search over a million pages in 19 journals on the web. And that will soon grow to 5 million pages in 20 journals.

Today the web is used to send and receive multi-media mail, to read and post to multi-media newsgroups, to calculate loan payments, to obtain and distribute software, and even to do simulations of nuclear reactors. The web is no longer something you just look at. Now it something you interact with. Today's web delivers services, not just multi-media documents.

The web can also assist in education. Not just in elementary school and not just for simple rote learning of things like multiplication tables or the capitals of the United States. Today's web can be used - and IS being used - to help students learn the most complex college material. The same web tools that will be demonstrated here to teach physics could be used equally well to teach Art History, Architecture, Economics, Hebrew, Psychology, and courses from kindergarten to graduate school. But the web isn't a substitute for professors, classrooms, and textbooks. Instead it makes all of these much more effective. For example, here I have a Physics textbook, a workbook, and an assignment from a professor to learn more about Fourier Analysis before the next lecture on the topic. And, oh yes, I'm fortunate enough to have some web tools that will help me do that. Now many of you haven't a clue as to what Fourier Analysis is, but that is just the point. Neither do students when they start trying to learn it. Fourier Analysis is a fairly difficult topic for physics and engineering students. And learning or teaching it is not easy. But using the web can help make learning even something as arcane as Fourier Analysis, compelling and entertaining.

To show you how the web could be used to help a student learn a complex topic such as Fourier Analysis, I'm going to use Addison Wesley Interactive's "Active Physics". This is a package of workbooks, references to all common physics text books, and lots of web tools - including browsers, Java applets, Quicktime movies, and much more than you'll be able to see in brief demo.

Let me first select the topic - "10.10 Complex Waves: Fourier Analysis". Notice that any student who's ever used the web already knows how to use this software. (end inset) The hypertext links, the frames, and all the browser tools work as expected for all computers running any operating system - since that's the way the web works. A student, of course, would always read the descriptive material on the web and in her text book first - but then again maybe she'd just hop right in to the simulation - and that works just fine too. We'll just start up the first simulation in this topic (of the 130 or so in Active Physics). If we do get into trouble, there is on-line help and on-line exercises to help us out.

Our task here is to understand how a complex wave - that blue saw tooth wave for example - can be formed from a series of sine waves. First I will use one of the sliders to set "n" - the number of sine waves in the series - to one. The blue saw tooth is the wave we're trying to build, and the red sine wave is the first approximation. Not too good a fit, is it? The two boxes below, track the sine waves in the time and frequency domain. In less technical jargon, the left box shows each sine wave in the series and the right box plots the corresponding frequency - color coded to match the waves in the left box.

Lets add a few more terms by increasing "n". Even a few more terms gives a very good fit. By 6 or 7 terms, the fit is close to perfect. At this point you might want to vary some of the other parameters or try some of the other complex wave forms to get a better feel for how Fourier Analysis works. Or perhaps to better understand what it means to fit a wave with the sum of sine waves it would help to HEAR it as well as see it. I'll start up one of the dozens of video clips and let it show you how that's done.

You might have noticed that the simulations and video clips seemed to run very fast. Obviously I must have a very fast web connection here. But in fact everything you see is coming from a CD-ROM supplied with Active Physics. Nearly all the web tools can be used from a CD-ROM with no need for a network connection. Accessing all the movies and simulations via a remote network connection would probably be very slow. Getting them off a CD-ROM solves that problem. Of course we could put the contents of the CD-ROM on a network and use the links to the Addison Wesley web page for updates and supplementary material. But, strange as it may seem, a student does not need a network connection at all to use this web application.

You can see that the web is charging off in many new directions. While you were trying to catch up to the way the web was yesterday, it has changed dramatically - and will change even more in the future. This virtual seminar will try to untangle the web for you. It will explore some of the difficult technical concepts and administrative challenges. and try to make them clear. You'll see how to use some of the basic web features - and some features that are quite advanced. You'll learn some browser basics, and both basic and advanced searching. You'll also see how to do web publishing, how to build and display databases on the web, and you'll learn the important roles of Java applets, JavaScript, and ShockWave - among many other things. Along the way you'll also learn the basics of coding your own HTML documents and JavaScript scripts.I'll also cover administrative issues, so that you'll know what is required to have a web environment that encourages your users to publish on the web and to use it to get their jobs done better.

Although this seminar will not turn you into a webmaster or a Java programmer, it will help you use the web more effectively today and prepare you for the changes that are coming in the future. But you should be fore warned. The web is changing very rapidly. It should not surprise you to discover that some of what you'll learn here today, will be different tomorrow.

About CREN

© CREN, 1999

Contact Us