Direct Hit is now powering most of HotBot's top results, a change that means clickthrough data is now heavily responsible for what appears in response to a search.
HotBot has not dumped Inktomi, but when there is relevant data from Direct Hit, those matches are presented on the first page of results, then Inktomi matches are listed next.
"We see this as a way for us to combine the true benefits of both of these technologies and provide people with the most accurate results," said David Pritchard, HotBot's marketing director.
Direct Hit is a system that measures what pages users select from search results and roughly how long they spend visiting these pages. In a very simplistic explanation, the more "popular" pages as measured by these factors rise to the top of the list.
HotBot had allowed users to view Direct Hit results in the form of a "Top 10" option that was presented along with Inktomi-powered results. If users selected the option, Direct Hit results were displayed in place of Inktomi's results. Now, Direct Hit data will appear in response to queries by default.
"We've made the change first and foremost because of the reaction we've had from our HotBot users. We had almost unanimous and unequivocal reaction from HotBot users praising the program and saying they greatly value this set of results," Pritchard said.
One question that often comes up when people consider the Direct Hit system is whether sites that are listed first in the results are given an unnatural advantage over sites listed further down. After all, the first sites will naturally attract more clicks than those buried in the results. Doesn't that mean they'll always continue to be ranked well?
The answer is that Direct Hit adjusts for these type of things. It knows the amount of clicks that a top ranked site would typically receive. If the top sites don't hit this average, they drop in rank. Similarly, the weight a click carries is magnified by how deep a site is buried. Five people visiting a top ranked site might not count for much, since a top ranked site should get many visitors. But five people visiting a site buried in the results carry much more weight in moving that site up the rankings.
With HotBot, Direct Hit says it has had to make yet a further adjustment, to compensate for the fact that the top listings in its refined results generate an even higher clickthrough than a typical search engine. For instance, it says the top spot in a typical search engine generates a 18 percent clickthrough, while its refined results shoot that rate up to 30 percent, because the match is much more relevant.
"We did have to make a change in the algorithm, and we've spent months figuring out what the right formula is," said Direct Hit CEO Mike Cassidy.
Keep in mind that I'm simplifying in the above examples, and there are other factors Direct Hit uses in its ranking algorithms. But the examples do give you a general idea on how the system works.
Another common question is whether webmasters can artificially boost themselves by simply clicking on their links many times. Direct Hit says it has systems in place to prevent this type of behavior, and I've not seen any evidence of the results being manipulated in the time I've watched the system. However, I think it has also been mostly ignored by webmasters. Now that Direct Hit results are the primary ones delivered by HotBot, it will be interesting to see if the system faces a stronger challenge by webmasters.
What if you don't like Direct Hit results? Professional researchers especially may not want user data interfering with complex queries they may construct. Generally, if you begin to use any of the advanced controls at HotBot such as field searching, Direct Hit won't have enough data to refine the results. Instead, you'll get all-Inktomi listings.
Aside from HotBot, Direct Hit also has debuted at ZD Net, where it is refining site specific searches. I was particularly impressed with how helpful it was when I came across the Direct Hit option last week. I was looking for articles about laser printers and was overwhelmed with the results that came up. But once I selected the Direct Hit option, I got a dramatically better set of results -- much more noticeable than the difference between Inktomi and Direct Hit results at HotBot. I wonder if Direct Hit's real strength may be in improving site specific searches, which are often woefully inadequate.
To use Direct Hit at ZDNet, just look for the "Top 10 Most Visited ZDNet Pages" link that appears just above the actual search results.
Finally, Direct Hit has always been a system that works with an existing search service, not one that can stand-alone. That's about to change. The company has developed its own crawling system, which means it can gather the raw data for customers without an existing search partner and then refine those results using its popularity measuring technology.
Getting Away From Words-On-The-Page Relevancy
The Search Engine Report, March 3, 1999
A sidebar to the above article that talks about the trend in getting away from words-on-the-page as a means of improving relevancy.
A Direct Hit on Inktomi?
Red Herring, Feb. 22, 1999
Some media have taken the Direct Hit-HotBot announcement as another slap against Inktomi. I think that's a bit strong. HotBot is not abandoning Inktomi, but the company will see a significant short-term drop in traffic from HotBot due to the Direct Hit changeover.
Searching In Dolby
Forbes, Feb. 20, 1999
Direct Hit is on a roll, and its main hurdle is that all the recent portal mergers push back the completion of deals.