Filtering
Notes
- All filters over block and all filters under
block.
- No two filters were created equal.
- Satisfaction with a filter is often based on
educational philosophy and is not a good gauge unless viewed in that
context.
- Filters and/or monitoring by themselves are NOT a
solution.
Blocking
- Keyword filtering results in the most blocking of sites that should
not be blocked because the word appears on the site.
- IP blocking results in the most blocking of sites that should not
be blocked, because they share the same IP gateway as inappropriate sites
- Black lists often block based on political, social, or business
agendas. This is becoming
increasingly popular.
- Domain name blocking is the most efficient and desirable method, but
is the least likely to be implemented, because it presents significant
problems for the filtering company bottom line.
- Schemes that combine varying degrees of Keyword, IP blocking, and
Domain name blocking that interact, provide the least disruptive type of
filtering.
- Closed systems restrict access to everything but the resources
within the system. They can range
from low cost, locally created access lists to expensive learning
environments.
Monitoring
- Packet sniffing provides a method of protecting students
without blocking anything, but can have serious privacy issues attached.
- Room design and teacher monitoring is a non-technical strategy
that could be implemented with the least objectionable technical strategy.
- Examination of log files can be time consuming. The efficiency depends on the expertise
of the person examining the logs.
-
Rating Systems and
Standards
- These can be browser
based or dedicated software
- The relationship between systems and
standards is often misunderstood.
- PICS is a
standard with which web authors can indicate what kind of content is on
their site.
- Third parties can create a system that
uses the standards to set blocking criteria.
- Rating systems reflect the values of the
groups that create the
Filter Logistics
- Client based may be a small-scale solution. Updating lists can be a problem. Expense must be examined. Easiest to
circumvent.
- Server based is usually the most cost effective and requires
the least amount of technical maintenance. Unblocking sites is a factor
that must be looked at closely because of philosophy and time needed.
- Servers can be at the school,
district, state, or ISP level.
Each comes with its own set of considerations about time, cost,
procedures and policies.