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--> First of all, there are cultural differences as to what is to be considered indecent. As an example, we can see
how a similar problem is handled in a different medium, the movies. American films are often quite heavily
censored when shown in Europe, because of a high level of violent content which is considered perfectly
acceptable in the USA. On the other hand, European films are often re-cut or X-rated in the USA because
they contain too sexually explicit scenes for the general public. What is indecent then, in the sense that it is
considered not suitable for minors or the general public, varies between cultures. Similarly, filtering software
must be customized for different types of scanning in different languages.
--> Secondly, harmless words used in a non-English language may be blocked out by English-based filtering
software such as SurfWatch, CyberPatrol and NetNanny. As an example, consider the word 'sex', which is
part of the standard filter-out list in CyberPatrol -- in Swedish it can simply mean the number '6'. Other
words in the CyberPatrol list which are incompatible with Swedish are 'love' which is the name of a famous
Swedish author, and 'sade' which is the past tense of the verb 'say'. Other languages have similar
incompatibilities.
--> Finally, the filtering situation gets even more complicated when the subject who is to be blocked out speaks
two or more languages. It is a fact that many young people across the world today learn and speak more than
one language. Filtering software must then be able to handle combinations of filters for different languages.
3. System Solution
Our system, called the World-Wide Market, handles transparent transfer of information between as well as within
different language groups so that interactivity is preserved, while at the same time avoiding the above problems
with unsuitable material. The three problem areas described above are addressed in this section.
3.1 Scoping of Service -- to Clarify Responsibility for On-Line Material
The system uses scoping to give the service provider full responsibility and control over what is published on the
system. Thus, the service provider can decide what level of "indecency" is acceptable, and easily change that
level in accordance with changes in regulations, etc. This amounts to a voluntary restriction, which may not only
be of interest to a provider because of fear for legal action. Other motivations include that the provider wants to
focus the service and reduce the amount of processor time used for unrelated activity, to qualify for the PICS
(Platform for Internet Content Selection) rating system, etc.
The system is based on an extended version of the classified ads sections found in many newspapers. The scope
of such a system consists of actions, intentions and sections as in the following example:
-> Actions : (Register, Insert, Delete, Update, Search, Browse)
-> Intentions : (Sell, Buy, Donate, Receive Donation)
-> Ad Sections : (Automobiles, Books, Computers, Electric Appliances, Music Recordings, Real Estate, Rental
Contracts, Video Games)
Users of the system communicate by establishing relations between several enumerations, in effect building a
subset with items from the involved enumerations. They are free to communicate anything within this scope, but
they have no way of going beyond it. A user could for instance select the subset (Search, Sell, Automobile), in
effect formulating the sentence: "I would like to search the sell ad listings for an automobile."
The scope can easily be extended by for instance adding other sections to include dating service, pen-pals,
offer of services instead of products, etc.
3.2 Enumeration of Vocabularies -- to Define Characteristics of Acceptable Material
Instead of concentrating on what it is not acceptable to say, we take the much easier approach of deciding what it
is perfectly alright to say. We do this by implementing sets of pre-specified topics and vocabularies which are
strictly enumerated and necessary to make meaningful statements in the above sections. We thus avoid the pitfalls
and complexities of huge free-form text translation systems. Problems with judging performance of such systems
[King 96] also make us wary of that approach. The number of possible combinations of enumerated vocabularies