If the groundhog doesn’t see its shadow, we have six more weeks of winter. But what if the user doesn’t see his or her treasured URL?

In that case it could get very wintry indeed, and that figurative winter might last much longer than six weeks.

Take, for example, the usually sure-footed Yahoo Last summer it quietly bought the eGroups discussion site. Suddenly last week, all the addresses changed to Yahoo Groups.

This made many users feel quite chilly toward Tim Koogle’s troops. “Did they warn users ahead? Nope! They didn’t even tell the list owners!” wrote Shel Horowitz. “For users who filter out messages from unknown URLs into a ‘spam’ folder, this was especially noxious,” he added.

“I suspect a lot of subscribers will have their stuff going directly to trash, and they won’t see ADMIN messages either. Only once these folks realize they’ve lost a week or so of mail will they try to investigate, and cause a lot of extra work for list owners, no doubt.”

Joan Faber, chair of the Association for International Business, has 11,000 members in 200 countries and was running a total of five lists on eGroups. “You had to go and add bells and whistles that are totally unnecessary… useless and confusing. It is a show of extreme arrogance.”

In the real world, change happens all the time. You put up new signs on a storefront and the old store is forgotten. But this is not true on the Web. Users have bookmarks and mail-handling procedures that change interrupts. So making changes in an ongoing business without notifying people beforehand can get you into real trouble.

People have long memories when they’re offended, but the Web can have a longer memory. Google caches pages regularly, so you can still find hundreds of eGroups pages using that search engine. This is true for any other major changes you may want to make on your Web site.

You can stop this if you want. Google’s cache of, for instance, carries no pictures, and clicking anywhere on it leads you to a page CBS.Sportsline created asking folks to wait for the new site, now under development by a unit of USA Networks. If you search for, now owned by Fashionmall, you’ll be offered a cache, but that link doesn’t go anywhere. News stories that are taken behind firewalls by portals or newspapers aren’t kept in cache, either.

So you can, if you (and your lawyers) like, fiddle with history and make your mistakes inaccessible through search engines’ cachea. But that does not mean you can completely erase the past.

Here’s an example. After I left Interactive Age Daily (I’d started their online daily in October 1994), CMP Media removed the paper from its servers. But a quick search of Google turned up a full page on a Thai server, a text issue cached at the University of Missouri, plus some quotes from an old issue maintained at the Open Software Associate’s Australian branch.

My guess is that the greater popularity of today’s Web means the mistakes you try to pull offline are even more likely to remain cached, somewhere, than my old work. It’s something to think about before you make any big changes.

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