Berlin  - Online forums have been around long enough that there has long since been one created for every possible topic, whether it be video games, medicine, legal questions or child rearing.

The forums allow interested parties to trade thoughts and pick up ideas from experts. But there's a hitch: not every forum is actually useful.

A good forum needs a strong moderator, says Jan Bruns of Computer Bild, a German computer magazine. Good moderating requires a balance between a hands-off attitude and "constructive, matter-of-fact co-operation."

That means jumping in to create new conversational "threads" when an existing one becomes bogged down by tangents. At the same time, a good moderator will seem to be a "passive authority" and act more like a regular member of the group.

A good indication of the strength of a forum lies in statistical data. If a forum can boast a number of longtime members, then that indicates that it is probably a useful and helpful portal. That means, for example, that tips in a technical forum are checked out to see if they actually work.

It's also a good sign if answers to questions include citations to other sources, said Astrid Auer-Reinsdorff, an attorney for IT law in Berlin.

It's always a good idea to see if the advice in an online forum is sound, says Auer-Reinsdorff. A user led astray by a misleading tip has no legal recourse against either the forum or the person who posted the tip in the first place.

There are exceptions if people post information from documents that contradict the law. Most forums have ground rules, setting terms of use and sanctions for violations, which can include blocking posts or users. Thus, checking to see how seriously a site takes its own ground rules can be another sign of how trustworthy a portal might be.

Another good sign is when a lot of users seem to know each other personally, says Claudia Eckert, a lecturer on information technology at Munich's Technical University. It's also good if the operator checks identities before allowing access and only makes content available to members.

Also check the operator's stance on IT security says Eckert, who is also director of the Fraunhofer Institute for Secure Information Technology. Pay special attention on its policy toward protection against hacking and data leaks.

Generally, one shouldn't initially reveal too much personal information. "In general, I should take care not to give out information that has a direct or indirect tie back to me," recommends Thorben Burghardt of the Institute of Information Systems and Management at the University of Karlsruhe. A person's name, address, hometown and telephone number should all remain secret.

Age is also a sensitive piece of data. "If necessary, in a forum, you can add or subtract a few years," advises Eckert. After all, one can never tell who's gathering and storing data to analyze it and eventually use it for their own purposes.

Even users of the most well-respected forums can still sometimes find their names gathered up into mass subscription lists if they click on a dubious ad, for example, warns Auer-Reinsdorff. Thus, the same rules apply in forums as anywhere on the web: any unplanned click can be one too many. (dpa)