Web conferencing is optimal when a meeting is basically a form of broadcast, where one person does most of the talking but there may be a few questions from the listeners. The technology is also effective when the speaker works from a document such as an earnings report or a PowerPoint presentation.

For global meetings, Web conferencing surpasses teleconferencing for broadcasting purposes because differences in language or time zones are exacerbated with teleconferences. With a shared document, the meeting can be more inclusive for a longer period of time. Conversely, if teleconferencing is used for broadcasting, the meeting should be shortened accordingly.

There are times when a meeting demands real interaction, and videoconferencing seems like a viable solution. But be forewarned that the technology leaves a lot to be desired, particularly when an international crowd is involved.

A year or so ago, I was on a global project for a large American electronics company where the Irish contingent felt (quite justly) that their needs were not being respected by the team as a whole. The company’s solution was to hold meetings using videoconferencing.

It was a nightmare. First of all, a lot of these videoconferences started at 1 p.m. (6 p.m. Irish time) and went on in the way of undisciplined meetings everywhere. When I was on (and I was on a lot), I tried to include our Irish colleagues, but I often failed?forgetting to look in the camera when things got interesting and neglecting to respond if the people in Ireland raised their hands.

By using videoconferencing purely as a substitute for an in-person meeting, we forced everyone to put in the same amount of time?and even more attention?that they put into a regular meeting. Yet we got only the illusion of personal contact.

Videoconferencing works better when only a few people are involved and when the meetings don’t have much formal structure. In essence, videoconferencing is fine when used by two people with Web cameras having a short conference but falls short when used by 20 people from three countries in an all-day marathon.

To facilitate communication on a global scale, there are three rules of thumb for using these technologies in a more nuanced way. First, the more broadcasting there is in a meeting, the more appropriate teleconferencing or Web conferencing is. But don’t expect the broadcast to be as effective as in-person broadcasts. Second, conferencing technologies put more strain on participants, so make videoconferences or Web conferences shorter than the corresponding meetings would be, and involve fewer people. Third, don’t expect any technology to substitute for travel. The remote participants at a Web conference just won’t take away what they would if they were meeting in person.