03.How we tested
We tested 15 net filtering software programs for performance, ease of use and flexibility, against 11 categories of potentially harmful material:
Abuse/exploitation — hurting or injuring by maltreatment; ill-use. Forced sexual activity.
Circumventors (proxies) — sites that allow access to blocked content and web pages by re-routing browser requests, 'circumventing' filtering software in the process.
Crime (illegal activity) — an act committed or omitted in violation of a law.
Drugs — any article intended to affect the function of the human body or animals.
False positives — mistakenly blocking non-offensive and possibly helpful sites, such as sex education.
Guns — projectile weaponry.
Hate speech — written/verbal attacks on a person or group on the basis of race, religion, gender, or sexual orientation.
Pornography — sexually explicit pictures, writing, or other material.
Terrorism — the unlawful use or threatened use of force or violence by a person or an organised group against people or property with the intention of intimidating or coercing.
Violence — physical force exerted for the purpose of violating, damaging, or abusing.
Warez (illegal software) — commercial software that has been pirated and made available to the public via the Internet.
All software was configured with the filters set to their default levels, as it is impossible to test all the different variations of settings for each program. Their performance was assessed using 'on-access' real time testing. For each of the categories, we entered a descriptive phrase into a search engine and collected 15 website addresses that contained explicit material. This list of sites was then used to test each filtering package in turn on cleanly installed systems.
Peformance was gauged on how well the filters blocked (or didn’t block) the material. We checked an additional 15 URLs for false positives, which is where the program blocks a legitimate site due to some misinterpreted language or image.
We also checked whether the programs could detect harmful material via a number of other mechanisms such as:
- Email attachment
- Email body
- Instant messaging
- Archived file
- Moved/copied/renamed/open file
- Removable media (USB key, external hard drive)
- Finally, we took note if any of the programs had a significant performance impact on web surfing.
Ease of use
This was evaluated taking into account software installation, updating and support information, as well as navigation and layout.
This was assessed based on the features, options and settings that were available. For example, filters that included advanced management capabilities scored higher than those filters that didn’t.