The cardinal rule for kids' computer use goes something like this: "Put the computer in a high-traffic area where parents can walk by and see what the kids are doing on it." This is a great rule, but unfortunately, it's not always practical. In our house, the ideal location would be the living room, but when the 12-year-old is up regularly until 10 P.M. doing homework on the computer, watching TV becomes prohibitive. Plus, since Teresa and I often need to use our computers in the evening for writing articles like this one, getting the kids their own computers became a necessity. But once you move the computer into the bedroom, how do you not only make sure they're on task, but also make sure they don't accidentally stumble across something inappropriate for their eyes? After all, it doesn't take long, even with "Safe Search" turned on, for a Google search to bring up something embarrassing at best and traumatic at worst.

Enter parental control software. Various companies have offered filtering software, usually for a subscription fee, but if you have multiple computers in the house, a "per computer" monthly fee can get pricey. More to the point, it's not really necessary with modern operating systems, since they have parental controls built in.

Filter methods

All content filtering software works off of one of three principles that give a varying degree of freedom and a varying degree of safety.

• White List filters allow the user to access a select amount of content: certain approved websites and email and chat to and from only approved people. This is the safest filter method because the parent approves every allowed website before it can be accessed, and nobody can communicate with the child without the parent approving that person. The only possibility for inappropriate content includes a site drastically changing its content, the parent being unaware of a site's content when approving the site, or spam being sent from a zombie computer using an approved person's email address. This method has the drawback of preventing many sites from being accessed not because they're inappropriate, but because the parent just doesn't know about them.
• Black list filters prevent the user from accessing a set list of sites and from communicating with a select list of people. This is by far the least effective filtering method and should be avoided. This method just can't keep up with the fluid nature of the internet, especially with spammers using new domains and new email addresses from moment to moment. It's like trying to rid a city of cockroaches be squashing one at a time.
• Content filters work more like a censor, scanning a website before displaying it. Inappropriate content either prevents the page from loading at all or gets replaced with an alternative word or symbol, the text equivalent of "bleeping" curse words on TV. This works with variable results, as images are difficult to filter perfectly by even the best software, and any number of synonyms or double entendres can make a page's content inappropriate without using any words on the filter's black list of words.

Mac OS X Leopard

Previous versions of the Macintosh operating system have used strictly white list filters for parental controls in Mail, Safari (Apple's browser), iChat (Instant Messaging Client), and iTunes. However, Leopard brings in the option for content filters in Safari.

As previously, you can lock in the "Simple Finder," which will keep file management to the very basics, preventing desktop and file system chaos.

Mail and iChat settings remain largely unchanged, except that you can add allowed people instantly to the address book. It would be better to just have a setting like iChat: allow mail only to and from people in my address book. The result is the same, but it can take a few extra steps.

Leopard allows parents to limit what applications the child can access, which is necessary if you have applications like Skype, Firefox, or online games on your computer, not to mention Disk Utility, which can erase your hard drive. The content filters only restrict the Apple preinstalled applications, so allowing Firefox access, for instance, would make the filters in Safari pointless.

Leopard uses the same content filter on Safari as it uses on the built-in Dictionary, watching for an undisclosed list of words. When trying to access a page with one of those blacklist words, Safari will prevent viewing that page. That said, I was able to find some explicit pages with the content filter turned on just be using words they hadn't thought to add to the filter, so you can't rely on this filter exclusively. 

Leopard also allows you to use a combination of content filter, white list, and black list, blocking sites you want to avoid completely like YouTube or MySpace that you may not want your young one to visit at all, but allowing certain sites you know to always be safe, like techtalkforfamilies.com!

Leopard also logs every page your child has surfed to, including a section of blocked pages. Chat and Application use logs will keep you informed as to whether they were really working on homework all night.

Finally, Leopard allows you to limit "screen time" on both weekdays and weekends, plus automatically shutting it down at a bedtime you determine.

Overall, the improvements in Leopard fall short of expectations, giving parents a false sense of security without enough content control.

Windows Vista

Vista, on the other hand, offers the most robust control I've seen in a bundled operating system. It includes logs and schedules like Leopard, but the other controls not only expand on Leopard's content filters, but they also add additional control features.

Where Leopard can manually turn on and off individual applications, Vista can do the same, but it also has content filters based on ESRB ratings for games. Given that the Mac hasn't nearly the gaming potential that Windows does, it's not as important on the Mac, but the Mac can never be considered a serious gaming system for families if Apple overlooks game content filters. The Vista game filters work much like modern PVR filters, allowing maximum ratings, but you can also filter out games with specific content you want to avoid, so if you're more concerned about violence than innuendo, you can block games based on individual content flags. (Although one of the flags is "educational," and why you'd want to block edutainment is beyond me.)

Vista's web filtering was also done right. Besides a complete white list or black list system, it has a "Medium," "High," or "Custom" setting. The Medium setting allowed me access to all of YouTube, including some very explicit content that Leopard had blocked, but Vista blocked Wikipedia completely, whereas Leopard had only blocked certain (not enough, though) pages. The "High" setting allows access only to a select list of kid-friendly sites, but that opens up a lot more than you ever likely could by adding one site at a time. The question, then, is whether you'll trust Microsoft to determine which sites are kid-friendly. The "Custom" filter works like the "Medium" by blocking certain content with parent-defined filters, a smaller set of criteria than those listed for game filters, but for most kids, checking most or all of the boxes in "Custom" will open up most of the "safe" internet. That said, content filters can never catch it all, any more than spam filters can recognize every spam message, so you'll have to decide how much control you want. At least Vista gives you that fine-tuned control that Leopard lacks.

Parental filters are only one of many factors in choosing which computer is right for your child, and commercial (paid) filter systems nearly always give netter options than the basic filters built into an operating system, but in this generation of operating systems, Windows Vista's parental control system beats Mac OS X Leopard's system hands-down.

So let's hear it: how do you control content on your computer? Leave a comment!