Even as the wrangling about the use of filtering software rambles on through the legal system, column aficionados have peppered my eMail with questions about some of the more practical aspects of content-screening programs.

Although there are lots of mixed messages in the media about filters, one important fact seems to be getting through to just about everyone ... except maybe some of the politicos: There is no filtering software that is 100-percent effective. In fact, all of this software has flaws that allow inappropriate material to slip through the gaps in the data network and, at the same time, blocks perfectly innocent (and often educationally useful) material.

The same is true of acceptable-use policies (AUPs). But while all AUPs are only as good as the people who implement them, well-reasoned and clearly written AUPs give users a better chance to make things work--including content filters.

While software filters use software to screen incoming material or block access to certain web site addresses, well-written AUPs can also make it more difficult for objectionable material to be received or accessed. No, the AUP does not lurk in the network like some super filtering algorithm. But it does establish some important parameters for how the internet is used and sets the policy for how filtering software is used. The symbiosis between filters and AUPs has several components.

The first and perhaps most important is the notice provided under the AUP that tells parents up front that any filtering software used by the school district is imperfect and that there is no guarantee that some objectionable content will not slip through. It also gives notice to users that trying to disable or circumvent the filters is grounds for withdrawal of internet privileges or other disciplinary actions.

A good district-wide AUP (you do have the school board adopt the same AUP for all your schools, don't you?) also will provide guidance to your information technology (IT) personnel on how to set the options on filtering software and what features are mandatory when selecting a filtering package for procurement and installation.

For example, many AUPs require that all filtering programs be capable of logging the time, date, and duration of internet sessions to the specific user (through a log-on capture feature) as well as to the final destination (in other words, tracking where the user wanders on the web). Of course, as some school districts have discovered to their chagrin, this type of logging program requires constant monitoring to have any real value. As in most aspects of the information age, simply collecting data doesn't do much good unless you actually use it.

Your AUP includes some important choices that guide the installation of your proxy server filtering software. One good choice made by many school districts is to block all access to "chat room" facilities on the internet. In these cases, the AUP establishes the policy that internet access cannot be used to chat online. Some school districts have a limited-use intranet chat facility that cannot be accessed from outside the internal school district network, but the education value of these activities is questionable. Most school districts also block "news group" access, which eliminates a major source of pornography and other cyber weirdness.