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Corrected Code4Lib slides are up

…at the same URL.

I was, to put it mildly, incredibly excited about code4lib this year because, for once, I thought I had something to say. And I did have something to say. And I said it. But it was wrong.

I presented a bunch of statistics drawn from nearly a year of Mirlyn logs. The most outlandish of my assertions, and the one that eventually turned out to be the most incorrect, was that some 45% of all our user sessions consist of only one action: a search.

Unfortunately, I’d missed a whole swath of things I should have excluded. I’d remembered robots and stuff coming in from our link resolver and so on. I hadn’t counted on having to fight my own stupidity.

In short: catalog.hathitrust.org and mirlyn.lib.umich.edu share a common code base, as well as a Solr backend. I was correctly excluding all the HathiTrust stuff from my stats except for simple searches. What I ended up with was a whole lotta sessions with nothing in them but that search. Luckily, I noticed waaaay too many people coming in via the HathiTrust site (which I know doesn’t have a link to Mirlyn) and did more digging.

The slides have been updated with correct numbers. Luckily, even though the adjustment was pretty extreme, I don’t think many of my conclusions are invalidated, especially given corroborating evidence from an extensive survey conducted by our usability team (PDF). They conclude, among other things, that known-item searching is prevalent and relevancy raking is important across task boundaries.

The basic stats from the powerpoint, for those who don’t want to read all my notes:

  • 17% of all sessions have one action: a search
  • —In only 28% of all sessions does the user see the Record View
  • 75% of all logged actions that target an individual record (see the full record view, look at extended holdings, etc.) happen with a record in the top 6 search results
  • 7% of sessions involve a user adding a facet
  • 2% of sessions involve a user exporting records