Virtual Classroom: a Model

Rationale:
While attending various conferences devoted to online teaching and learning I noticed
that many of the individual experiments and implementations presented there,
different as they were, had many elements in common.
This article is my attempt to step back from the implementation level and gather
these common elements into a comprehensive model of online classroom,
which, hopefully, will be applicable in different settings.
Strictly speaking, it is not a theoretical model but rather a practical blueprint,
hence it contains multiple examples of, and references to actual tools
that fulfill the various requirements of the model.

Table of Contents:

1. Introduction

What constitutes a classroom? When confronted with this question, what often immediately comes to mind are the elements of the physical infrastructure from classrooms we spend so much of our lives in: a blackboard, rows of desks, cabinets full of instructional materials, an overhead projector... This is quite legitimate and not surprising, as it is the image our brains are most likely to evoke when we close our eyes and try to imagine "a classroom". Yet this way of thinking about it has profound limitations, because, at the most basic level, classroom is a space where structured and planned teaching and learning happens, and this can happen under a palm tree, in a tent in the middle of a desert, and in many other places, where most or all of the infrastructure of a Western-style classroom is simply not available. In most of those places this could, of course, be changed by building a school and bringing in the needed equipment, but in one environment this will never be possible: the online "virtual classroom". Here it is not merely a matter of deprivation, to be alleviated by more resources; quite the opposite: online learning requires an extensive - and often costly - infrastructure of its own and so it is, at least at the moment, a domain of the well-to-do nations. Growth in global prosperity will not make it disappear (as it may be the case of open-air classrooms in remote villages) but rather contribute to its expansion. Therefore, when attempting to create a model of a classroom in the online environment, it is no longer useful to think in terms of blackboards, backpacks, textbooks, and desks; instead, one needs to look at its essential elements from a very different angle. In my own attempt I chose to focus on what is happening in a classroom and divided it into five distinct categories, which thus became part of the universal  model, applicable (I hope) to both the physical and the virtual environments:
  • Presentation
  • Discussion
  • Practice
  • Testing and grading
  • Social interactions
It is not my intention here to propose a new definition or a theoretical model of classroom learning; my five categories were arrived at intuitively rather than  empirically. Their purpose is to ensure that the practical model of a virtual classroom, which I'm about to fill with suggested technological components, is complete. This article is targeted, primarily, at those, who build virtual classrooms, in the hope that it will serve as a customizable blueprint and a checklist to help them develop online learning spaces that are at least as effective and versatile as those in the physical world.
 

2. Presentation

Live presentation is probably the most common method of knowledge dissemination in the world of structured learning. Its forms and its place in the classroom underwent significant changes in recent decades, but it remains an important tool in any teacher's arsenal, and, if done well, a powerful one. In today's classrooms presentation is no longer limited to lecturing from behind a lectern or to simple show-and-tell, but can be augmented with rich multimedia elements made possible by slide projectors, VCRs, CD players, television, and, most recently, computers. Although some critics decry the overuse of multimedia and dismiss it as "edutainment", its contribution to the learning process can be quite significant, and, for better or worse, students now expect it as naturally as their parents expected the squeak of chalk on a blackboard.

While it may be at least a decade before we may be able to offer our students the sensation of touching a fish or smelling sulfuric acid online, most visual and aural experiences available in a "real" classroom can fairly easily be recreated in the virtual world. In fact, the World Wide Web, which initially consisted mostly of hyperlinked text files spiced with occasional images, has evolved into a world where images and sounds are becoming the primary conveyors of meaning (to the dismay of the advocates of the disabled). Gains in modem speed and improvements in compression algorithms have enabled most users to view high quality, full color images; to listen to audio broadcasts or download music clips; to view real-time or recorded video; to be entertained or informed through interactive animation.

2.1 Text and images

As it is no longer possible to experience the Web on a text-only browser like Lynx, it would make little sense to limit our choice of media for presenting content in a virtual classroom. Making text and images available to the students is incredibly easy these days. Each of the dominant OS platforms (Unix, Windows, MacOS, Linux) has at least one good Web (or HTTP) server available for free or at a very reasonable price. Among the best and most popular are: FastTrack, Enterprise, Internet Information Server, and WebSite Professional. They are relatively easy to setup and administer, in most cases providing the webmaster with a browser-based, visual interface and a good selection of tools, including fine-grained access control. Publishing content onto one of those servers has also become easier; FastTrack and Enterprise provide a "one-button publishing" mechanism, which, when used with Netscape Composer, allows the user to edit or create a page - in a WYSIWYG environment - and place it on a server simply by providing a URL to it; Microsoft FrontPage, a powerful add-on to the Internet Information Server, has features that greatly simplify Web site creation, such as drag-and-drop publishing and templates.

As if it weren't simple enough, software such as Trellix and Net-It Central omit the use of Web page editors entirely and instead automatically convert almost any type of document provided by the user - including popular office applications such as Word, Excel, PowerPoint, etc. -  into Web-accessible files. Dragging-and-dropping a document into a desired folder not only triggers the conversion process, but also positions the new file in the appropriate place in the site's hierarchy of links, which are then automatically updated. Besides speed and simplicity, another advantage of using this process lies in its ability to preserve the original layout of a document, often lost in the more intrusive conversion to a standard HTML. However, this means that the documents cannot be viewed in a standard browser and that some sort of a viewer (a plugin or a Java applet) must be provided. Also, these solutions tend to be expensive and thus are more appropriate for big corporations or large departments, where significant number of documents created in specialized applications need to be disseminated via an intranet. In smaller endeavors this is unlikely to be cost-effective.

Finally, many of the ready-made virtual classrooms provide content publishing mechanisms of their own. Some, such as TopClass, do require that a person doing the publishing has some knowledge of HTML coding; others supply simple fill-in forms which curtail formatting but turn the posting of material into a cut-and-paste operation. (I'll keep mentioning the ready-made, integrated environments throughout this article, whenever one of their components fits the category under discussion. More about them in the section on Testing and Grading, where their advantages are most evident, and in Appendix A, where I compare and contrast the integrated packages with the "patchwork" approach to building virtual classrooms.)

2.2 Audio and video

Disseminating audio and video via the Web can also be done through standard HTTP servers, simply by placing the files in appropriate directories and linking to them from a Web page, so that users can download them to their computers and play them back at their convenience. However, due to typically large sizes of these files and thus long downloads at modem speeds, the preferred method of online audio and video presentation is "streaming". This method transfers only a small portion of the file at a time - usually no more than a few seconds - to be played back immediately, while the next portion is being downloaded in  the background. The biggest advantage of streaming lies in its immediacy, but since it is heavily dependent on network conditions, low modem speeds or congestion often result in "choppy" audio or low frame rates, sometimes to the point of turning a video clip into a slow and grainy "slide show", as download can no longer keep up with playback, and packets of data are being dropped from the stream in order to speed up transfer.

Streaming also usually requires a specialized server, such as RealNetworks' RealServer G2 or Microsoft's Windows Media Services, although most HTTP servers are capable of streaming certain file types as well. The good news is that basic versions of streaming servers, perfectly sufficient for individuals, groups, and small institutions, are available as free downloads from their vendors. They may lack more advanced features, e.g. real-time broadcasting, or limit the choice of compression algorithms for encoding content, but these are not likely to be used in basic applications anyway. Setting up and administering such a server is not very difficult, especially under Windows NT with its familiar graphical user interface. Several attempts were made in recent years at breaking the chokehold of RealNetworks and Microsoft on Web delivery of streamed multimedia by circumventing the server requirement (examples include Emblaze and VideoNow), but most quickly faded into obscurity, with the notable exception of Macromedia Shockwave, which remains especially popular for delivery of interactive animation with sound.

My comments about the relative ease of use and low cost of tools for multimedia streaming do not automatically apply to real-time broadcasts of audio and video, where the levels of cost and difficulty are somewhat higher. Preparing a multimedia file for on-demand streaming may be time consuming but its hardware and software requirements are often quite low. For example, one can easily add spoken narration to a set of PowerPoint slides by recording it via an inexpensive microphone onto a local hard drive, and then export the file into a "streamable" format to be placed on a RealServer G2 or Windows Media Services server. Upon playback, the slides will advance automatically and the users will be able to listen to the narration via a set of computer speakers or headphones. All of this can be done quite effectively on a 133 MHz Pentium-class computer with a 16-bit sound card and a 28.8 modem.

2.3 Real-time multimedia

In contrast, a real-time broadcast of slides and audio (not to mention video) requires not only more powerful hardware, but also bigger, more stable network throughput, and full-featured server software, which may cost from several hundred to several thousand dollars, depending on the number of simultaneous streams and other factors. Launching a real-time multimedia event is also a few notches more difficult than creating files for on-demand playback. It may require, for example, a good grasp of such networking concepts as unicast and multicast, and assuring that all clients to be connected to the event stay within a fairly narrow range of acceptable hardware and software. The plethora of options for real-time delivery of multimedia adds a bit to the confusion, at least initially. Let's examine those options briefly:
  • One-way versus two-way communication. Streaming servers from RealNetworks and Microsoft mentioned above deliver multimedia in a classic broadcast fashion, i.e. in only one direction: from the server to the connected clients,  while software such as Netmeeting or CU-SeeMe are more akin to telephone (or videophone) appliances, where all connected users can switch between receiving and sending fairly easily.
  • Point-to-point vs. multipoint connections. Often (although not always) the two-way communication severely limits the number of participants in a single event, sometimes to two only. It may be due to high bandwidth requirements of such sessions or to non-technological obstacles, e.g. several people trying to talk at once are much closer to cacophony than discourse. The streaming servers, on the other hand, allow much larger numbers of participants, in the range of tens or hundreds, without much of a deterioration in the event's quality.
  • Unicast vs. multicast mode of delivery. In the more prevalent unicast mode, all clients receive their streams directly from the broadcasting server, so the size of the audience is limited by the throughput of the "data pipe" connected to the server. In the newer, more efficient multicast mode, the central server delivers the broadcast to a number of intermediary servers, to which the clients then connect. Bandwidth bottlenecks can be prevented by distributing the clients among a greater number of servers or by introducing yet another layer of servers between clients and the broadcaster. However, many networks have not been configured yet for handling multicast.
Two-way communication and multipoint connections are clearly preferred in a virtual classroom but the technology to make it possible in the Web environment has only started to emerge and so the tools are hard to find, expensive, and unreliable. The list of leaders in this area is fairly short and includes:
  • Centra with its Symposium, a sophisticated tool offering multiway audio conferencing, application sharing (several users editing single MS Word document or inputting formulas into single MS Excel spreadsheet); whiteboard (several users scribbling on a white space or annotating an image); collaborative Web browsing (also known as "Web tours"), floor sharing (at the discretion of the session leader, an audience member can temporarily take on the role of a presenter); group breakout sessions, textual chat, polls and quizzes, post-session surveys, threaded discussion, and virtual hand raising
  • Placeware with its Conference Center, similar to Symposium, but built around the metaphor of a real-life auditorium, with a stage, rows of seats, etc. Narrated sideshow is the primary mode of presentation here, although Web tours and whiteboard capabilities are provided as well. Live sessions can also be recorded for on-demand playback later.
  • DataBeam with its neT.120 Conference Server, which allows Netmeeting clients to overcome their limitations and engage in a truly multipoint session with two-way audio and video, and the Learning Server, a ready-made virtual classroom, where the Symposium-like conferencing client is but one component of a feature-rich, complex environment.
There have been a few more or less successful attempts at creating some sort of "middle ground", i.e. combining the cheaper, more reliable, one-way video and audio communication tools with low-tech multiway solutions such as traditional phone conferencing or textual chat. One particularly good example of such a hybrid is the Interactive Broadcasting Suite from Netpodium. It uses the relatively mature and ubiquitous RealMedia technology for delivery of the audio portion of a slide show presentation, while allowing users to send typed questions to the presenter and to express their opinions by responding to live polls. Interestingly enough, even some of the vendors of the more cutting-edge tools  (e.g. Placeware) advocate using standard phone conferencing with their products rather than the built-in IP audio mechanisms, which can be quite challenging to an average user.

To summarize: choices for online presentation of educational content are aplenty and cover a wide range of media, from text and images to animation, to audio and video, to narrated slideshows, to live application demonstrations. Some of those choices are still quite costly and relatively tricky to implement, but many are free or inexpensive and do not pose a challenge when it comes to installation or maintenance. Furthermore, clever combinations of the simpler tools may create environments that are as robust and feature-rich as their sophisticated cousins, but at a fraction of the cost.
 

3. Discussion

We all know the main reason for organizing students into classrooms: to make it possible for one teacher to teach multiple students (hopefully effectively). It is cheaper and more practical than to have a teacher work with one student at a time. Another important reason, often overlooked throughout the history of world's educational systems, is that in a classroom students will also learn from one another.  In fact, good teachers will frequently step aside and encourage free flow of knowledge, experiences, and unique perspectives their students bring into the classroom. There are, of course, multiple ways of doing this, but the most common is engaging students in conversations relevant to the topic of study. These conversations may involve the class as a whole or groups of students; that may be structured or spontaneous; they may take place inside or outside of the classroom; may be initiated by the teacher or the students themselves.

Holding conversations (discussions) online is relatively easy and very often takes the form of sending/receiving e-mail messages to/from a group of people. However, given the limitations of this method:

  • each user has to organize and maintain his own archive of messages in a discussion
  • file attachments sometimes get lost or are made unreadable as a result of the transfer process
  • the only way to connect messages in a discussion is by including ("quoting") the text of some or all previous messages in the body of subsequent ones
one should really look into alternative discussion mechanisms, all the more that powerful, inexpensive alternatives are aplenty.

My perennial favorite is O'Reily's WebBoard - a $699 stand-alone server with long list of features and easy-to-use, intuitive interface which requires only a Java-enabled browser for full functionality. Armed with a browser and a URL, a user can log into any discussion board on the server, see the hierarchy of postings at a glance, read messages, compose and post a new message (or a reply), even engage in a real-time chat session with other users, who happen to be connected to the server. Nothing fancy - just the basic features of almost every other discussion group server. Where WebBoard really shines is in the implementation of these features and in a handful of other ones, not always present in other packages:

  • multiple "virtual boards" can be created, each with its own URL and a set of discussion topics. (The license places no limitation on either the number of virtual boards, number of topics in each, or the number of user accounts).
  • split-window view allows the user to browse postings in any order, without losing sight of their place in the overall hierarchy
  • file attachments (including images, documents, sounds, even small programs) may be posted alongside messages
  • users can edit or delete their own postings at any time
  • fine-grained access control can block specified users from posting to or even seeing particular topics
  • support for mailing lists means that users who choose to do so, can receive and post discussion messages via e-mail, without using their Web browsers, but with the advantage of having a structured archive of the discussion maintained for them and available at any time.
All this makes WebBoard an undisputed leader of the pack, with other solutions lacking in features (e.g. Caucus), requiring third-party servers (e.g. Allaire Forums), or being grossly overpriced (e.g. eShare Expressions). However, an interesting alternative has been presented by eGroups and Delphi Forums, both offering discussion boards - hosted on their servers and supported by advertising banners - entirely for free. Although not as robust as WebBoard and presenting somewhat of a risk due to lack of control over the server, these offerings can be quite attractive to schools and colleges with limited financial and human resources, by allowing them to save not only on the cost of the software itself, but also on hardware and maintenance costs.

4. Practice

Whether it be carpentry, calculus, or screenwriting, practice is an inextricable part of the learning process. That's why schools spend large sums of money on lab equipment, why teachers assign and grade homework, why "deliverables" of all sorts (posters, models, essays, project documentation, etc.) are required in almost every classroom. As I already mentioned, it is (still) very difficult or impossible to recreate the entire range of a student's classroom experience in the online environment; one cannot expect a basketball team members to meet for their practice in a chat room, or to educate a car mechanic without having him work on a real car. Obviously, certain disciplines will fit more readily into the online environment than others, or even tap into learning opportunities that are hard to come by in the real world.

Let's consider, for example, foreign language classroom. Audio and video technology have already added significant enhancements here, but the Web is adding even more and new ones. Students are now able to interact with native speakers of practically any language as if no physical distance existed; huge number of cultural artifacts, including museum collections, radio broadcasts, newspapers, TV guides, bus schedules, etc., become available without requiring the student to travel abroad; it is easier than ever to approach the teacher and the other students with questions and requests for assistance. Powerful tools have also been given to students in other disciplines, who can access or even control sophisticated scientific instruments in remote locations; gather enormous quantities of data in very short time; run simulations of complex systems that would otherwise take years and huge budgets to monitor.

4.1. Synchronous

In fact, in many areas today one can practice acquired skills without rising up from a desk chair. What is required is access to the tools necessary for a practice session, and a communication channel with the instructor. Both requirements can often be more easily met in the online environment than in the "real world", even in settings where some "hand-holding" is necessary, i.e. for the teacher to be present while a student goes through the steps of the practice activity. In such a setting  one would probably want to use online communication software that allows remote control or application sharing. Taking control over someone's computer at a distance is not a new concept and, contrary to what some people may think, does not require telepathy ;-). Hackers have been at it for many years. The challenge is with making it visible, so that someone, whose computer has been taken over, can easily follow all the actions of the person currently in control. This challenge has been successfully met in products such as PC Anywhere, Timbuktu Pro, or Netopia Virtual Office. Any one of the three solutions can be used, for example, by a teacher to show how to use a particular feature of a complex program; or to invite a student to demonstrate his level of familiarity with that feature; or to correct mistakes students may be making while using an application. They can also be used to exchange files between two connected computers, so that the "fruits" of a student's practice assignment can be transferred to the teacher for comments and evaluation.

Application sharing works on the same principle as remote control, but instead of taking over the entire operating system of a host computer, the remote "controller" is allowed to operate only on a specified application, say, a word processing program or a database design tool. It is also limited to applications running under  Microsoft Windows and not available to users of Macintoshes or Unix workstations. In most cases it is necessary to obtain and install specialized client software, such as Microsoft Netmeeting (an undisputed leader in this category), but successful attempts have been made at making this functionality available to Web browsers through a Java applet. WebEx Meeting is a wonderful example of such an attempt; any user with a Java-enabled browser can start an ad-hoc conference session through the WebEx Web site and invite others to participate. Unfortunately,  while many powerful features of online conferencing (chat, whiteboard, slide presentations, document sharing) are available to users for free, sharing of live applications requires a paid subscription to the service, and the price is quite steep. However, it may well be the first of many such solutions, which may end up being adopted by the next generation of - hopefully still free - Web browsers.

4.2. Asynchronous

Of course, not every practice requires a real-time participation of the instructor. In most cases the student is simply given an assignment, instructions on completing it, and a deadline; it is then up to the student to find the time to do it and to deliver the product, while the instructor may or may not intervene in the process.  It is not difficult to setup an online environment that would support this mode of practice. At the minimal level even simple e-mail messages with file attachments might be all that's needed. Or setting up a folder on a server for the students to ftp and retrieve or post files. At a little more sophisticated level one may want to reach for tools that enable transfer of files through a Web browser; that keep track of subsequent versions of a file; that allow viewing a file without downloading it and opening its native application. DocuShare from Xerox fits these requirements perfectly and even throws in a few more features, such as scheduling (e.g. for setting up milestones and deadlines), bulletin board (for reminders and comments), and a powerful search engine, capable of looking inside of files. TeamWave Workplace goes even farther and provides an impressive selection of tools not only for storing but also for creating content: database, drawing board, flowchart designer, and more. It also works well in both the synchronous and the asynchronous mode; authorized visitors to the Workspace can work on their own projects at their own time and pace, but whenever there is at least two of them connected at the same time, they have the option of engaging in a number of synchronous activities, such as chat, collaborative browsing, or modifying a common object (e.g. a database). It is truly a remarkable tool, despite the fact that its interface is one of the ugliest around and that it requires installation of a separate client, written in Java. These shortcomings are easily forgiven when one considers that a comparable tool such as eRoom costs 5 times as much per user...

5. Testing and grading

Let me begin this paragraph by stating that I have serious misgivings as to whether testing should be treated as an essential component of an online learning environment. Clearly, it still has an important place in the real classroom, but even there it has been overshadowed by the emphasis on projects, portfolios, teamwork, etc. Furthermore, each step of the educational ladder means less reliance on tests and more on other means of evaluation; for example, a  graduate student encounters far fewer tests than a junior in an undegraduate program. In both the online and the real-life environments testing alone provides a good number of challenges: making sure that the person taking the test is the one expected to; providing unique test questions for each student; timing the test; automated evaluation of multiple-choice and yes/no answers; etc. When one adds to it the requirement of shielding each student's grades from the curiosity of his classmates (luckily, a non-issue in most countries outside of the US, where grades are simply posted for all to see), the challenges become overwhelming. Therefore, it is hardly surprising that even bold experimenters, like the team behind the Florida High School, require their online students to take tests and exams at their local schools.

Personally, I am not very fond of ready-made, integrated "virtual classrooms". To be fair, they do have advantages over "patchwork" solutions (see Appendix), but one doesn't have to be a technological genius to find and implement a suite of tools that, combined, will offer more power and a greater range of features than any prefabricated package currently on the market. However, there are not that many vendors offering tools that focus on testing and grading, and those that do, tend to charge so much for them, that it makes little sense not to turn one's attention toward integrated solutions, as most of them offer this feature at no additional charge; unless, of course, testing and grading is all one needs.  Blackboard CourseInfo, as well as its free version, Blackboard.com, offer rudimentary but sufficient gradebook, and forms for building simple tests and quizzes.
TopClasss is less intuitive and more confusing to navigate than both Blackboard offerings, but its testing capabilities are slightly more robust, offering support for several types of questions (true-false, multiple choice, essay, etc.), automatic grading, and reports for monitoring student's progress. The eCollege System takes it all off the teacher's head by promising to custom-build an online course around the content provided by the teacher and to his specifications. The course is then hosted and maintained on eCollege servers, eliminating the need for costly hardware purchases and for setting up complex security mechanisms locally.
 

6. Social interactions

Classroom is a social place. Getting to know other students, forming friendships, chatting about common interests, expressing one's emotions -  for better or worse, those are all important elements of the environment we call "classroom". In the "real" world they occur quite naturally, prompted by the sheer physical proximity of the students to one another, without any intervention from the teacher (sometimes despite teacher's efforts to the contrary...). It isn't so in the "virtual" classroom, where students have little or no chance of meeting each other in person, and where extra effort is often needed for social interactions to occur. One may feel tempted to abandon these efforts for the sake of concentrating on the didactic side of online teaching, but this is a shortsighted strategy, likely to have a negative effect on the overall learning experience of the students.

The good news is that most of the tools that support online presentations, discussions, and practice, can be used to support social interactions as well. With some, those interactions may even happen as naturally and spontaneously as in the "real" world. For example, participants in a Placeware Conference Center session appear to be seated in "rows", up to eight people in each, where they not only see the names of people in their row, but can strike a conversation at any time, either by typing messages in the supplied chat window, or using their microphones to converse via voice. Given the fact that neither the presenter, nor other audience members are even aware of in-row conversations (unless they themselves move from one row to another), this feature seems to be serving primarily as a socializing agent. So much so, that the presenter has the option of turning it on and off, like a teacher putting a finger on his lips and ordering the students to be quiet and listen (albeit much more effectively...).

Chat servers can be used for online meetings and brainstorming sessions, but also for informal chit-chats about movies, weather, hobbies, etc. When a tool like WebBoard is used for online discussions, teachers often create a conference called "Introductions" and ask the students to submit short messages describing their background, interests, and any other personal information they may want to reveal, including their photos. This serves as a good "icebreaker" and helps build the sense of camaraderie among students that otherwise may feel quite isolated. Rather than turning into repositories of dry statements about people's educational backgrounds, these introductory conferences often hold very personal, even intimate messages. I've seen a posting from a student whose hobby was playing a guitar and who chose to attach several sound clips containing samples of his play. Another student, deeply involved in a homosexual relationship, wrote beautifully and eloquently about her partner in this relationship.

Finally, videoconferencing software such as Netmeeting or CU-SeeMe may help us attach a face (and facial expressions) to a name and a personal statement left on a discussion group server. In fact, pushing video streams through network bottlenecks in order to show students a "lecturing head" adds little educational value to a lecture and tends to be distracting. Much better return on investment (metaphorically speaking) can be provided by using videoconferencing as a medium for getting to know each other and for social interactions.

Appendix

Creating a virtual classroom is like buying a house; the first one we see has beautiful bathrooms, but the living room and the kitchen are simply too cramped; the second one has a dining room worthy of a castle, but the rest is horrible; the master bedroom in the third is ten times better than the bedrooms in the previous two. Wouldn't it be great, if we could buy only the parts we like in each house - bathroom here, living room there... - and then glue them together into a dream house? (Chances are, we would end up with a house that looks simply awful from the outside, but is it really that important...?). While this is impossible, at least for the time being, in the world of real estate, it is a valid choice to those of us who are thinking of having virtual classrooms: we can go and buy a prefabricated solution or attempt to put one together from independently purchased components. Both approaches have trade-offs, some trivial, some quite significant: simplicity for features, convenience for customization, easy administration for modularity. The table below lists those in detail.
 
Ready-made environments
Custom-built environments
Monolithic; unused parts can not be easily removed or new parts added. Modular; parts of the environment can be added or replaced almost at will.
Generally easy to setup and administer. Various components are setup and administered separately.
Consistent, homogenous interface. Interface may vary from one component to another.
Single account gives user access to all the features. Multiple accounts for a single user are often necessary.
Particular components are often not as robust as those in tools built around a single component (e.g. a chat server). Freedom to choose the best components currently on the market (e.g. best chat server, best discussion group server, etc.).
Long-term commitment to a single vendor. Multiple vendors, minimal commitment.
Remote-hosting option usually available. Usually require in-house installation and maintenance.
Rigid; new technologies incorporated at the discretion of the vendor. Flexible; makes it easier to follow and incorporate new technologies.

©1999 Vlad Wielbut and the Alliance for Community Technology