Tuesday, February 21

Yahoo -Advanced -Search AND MSN anti-contextual ads

I was using Yahoo today and discovered what I believe to be a bug in their advanced search functionality. The minus (-) operator does not appear to function correctly.

See for yourself.
  1. First, try a search for "valves".

  2. Next do a search for "valves -pumps". The first result is for www.breastfeeding.com, which does not have any on-page mentions of the word valve. Furthermore, it contains the word "pumps" very prominently in relation to breast feeding "pumps & pumping."

  3. Finally, just to see the extent of the brokenness, do a search for "valves -12345678910111213". Hopefully, I have picked a string unlikely to occur in any common search result. However, instead of returning the original set of results, we are back to breast pumps and motor sports.
It's very surprising to see this from Yahoo. Has anyone else noticed this? None of the other major SEs have this problem. Time to file a bug report. However, Yahoo appears to be missing something I think is important:

In light of Yahoo's "Social Search" initiative, I hope I'm not the only one who sees the irony in this.

In the process of showing this to co-workers, we stumbled upon another interesting "feature", this time in MSN. MSN ads do not handle the minus operator. Try a search for "valves -pumps".

The "contextual" ad results are exactly what we subtracted from the query, with some stemming! Try just "valves" to see the difference. Thanks to my co-worker, Joan, for pointing this one out to me. Possibly a result of the way their ad code is parsing the query terms?

That's about does it for today's search engine "feature" round-up.


  1. I noticed the same thing about Google's "-" operator. It is also broken. I made a comment about it on Battelle's blog, here.

    So it's not just Yahoo and MSN that can't quite get it right.

    The wierdest thing about the Google search is that the query "olympics -torino" doesn't make the video search box go away.. but "olympics -chevrolet" does! I'd honestly like to hear the explanation for that one.

    However, the latter query still does not make the chevrolet ad go away.

  2. I do see your point that the "-" operator does not work properly for the context ads on Google.

    However, it appears to work fine for the Organic search results. This is not the case for Yahoo.

  3. I found this article interesting and was going to click on an ad for you, but unfortunately the only contextual ads Google offered up were about breast pumps. go figure.