[ update: slightly revised stats are available here! ]
We've just started collecting in-depth data about how students are searching Summon (keywords entered, facets selected, etc) and I thought some of you might be interested in an early analysis from the last 7 days (just under 40,000 separate searches by 2,807 students)…
- On average, students used 4.5 keywords per search (the mode is 3 keywords and the majority of searches used 3 keywords or less — view graph) 
- 30.6% of searches used at least one facet to refine the results 
- 11.7% of searches were refined using the content type facet (e.g. newspaper articles, book reviews, books/ebooks, journal articles, etc)
- 9.5% of searches were refined to just items with full text available online
- 9.2% of searches were refined by publication date 
- 7.2% of searches were refined to just articles from scholarly publications (including peer-review)
- 3.4% of searches were refined using the language facets 
- 2.6% of searches were refined using the subject term factes
- 2.3% of searches used a Boolean operator, with AND being by far the most common (2.23% of searches) 
 – One student copied & pasted the following 356 word title & abstract into the search box!
Peter J. Shaw, David J. Rawlins Article first published online 2 AUG 2011 DOI:10.1111/j.1365-2818.1991.tb03168.x 1991 Blackwell Science Ltd Issue Journal of Microscopy Volume 163, Issue 2, pages 151–165, August 1991 Additional Information(Show All) How to CiteAuthor InformationPublication History SEARCH Search Scope Search String Advanced >Saved Searches > ARTICLE TOOLS Get PDF (1119K) Save to My Profile E-mail Link to this Article Export Citation for this Article Get Citation Alerts Request Permissions Share Abstract References Cited By Get PDF (1119K) Keywords Confocal microscopy;three-dimensional fluorescence microscopy;point-spread function;deconvolution;computer image processing SUMMARY We have measured the point-spread function (PSF) for an MRC-500 confocal scanning laser microscope using subresolution fluorescent beads. PSFs were measured for two lenses of high numerical aperture—the Zeiss plan-neofluar 63 × water immersion and Leitz plan-apo 63 × oil immersion—at three different sizes of the confocal detector aperture. The measured PSFs are fairly symmetrical, both radially and axially. In particular there is considerably less axial asymmetry than has been demonstrated in measurements of conventional (non-confocal) PSFs. Measurements of the peak width at half-maximum peak height for the minimum detector aperture gave approximately 0·23 and 0·8 μm for the radial and axial resolution respectively (4·6 and 15·9 in dimensionless optical units). This increased to 0·38 and 1·5 μm (7·5 and 29·8 in dimensionless units) for the largest detector aperture examined. The resulting optical transfer functions (OTFs) were used in an iterative, constrained deconvolution procedure to process three-dimensional confocal data sets from a biological specimen—pea root cells labelled in situ with a fluorescent probe to ribosomal genes. The deconvolution significantly improved the clarity and contrast of the data. Furthermore, the loss in resolution produced by increasing the size of the detector aperture could be restored by the deconvolution procedure. Therefore for many biological specimens which are only weakly fluorescent it may be preferable to open the detector aperture to increase the strength of the detected signal, and thus the signal-to-noise ratio, and then to restore the resolution by deconvolution. Get PDF (1119K) More content like thisFind more content like this article Find more content written by Peter J. ShawDavid J. RawlinsAll Authors ABOUT USHELPCONTACT USA
…sadly, Summon failed to find a result for that as we don't subscribe to the article!
 – Normally, you search Summon by entering your keywords then, after the results appear, you select facets to refine your search and each facet selection invokes a new search. So, if you ran a search and then select 2 facets, that will be logged as 3 separate searches (1 without any facets, and 2 with).
 – Mostly, the publication date facet is being used to limit the search to the X most recent years.
 – The vast majority of the content in our Summon instance is in English and, apart from one search that refined the results to just Italian, every use of the language facet was to refine the results to English only.
 – Boolean operators have to be entered in UPPER CASE in Summon, with an invisible AND being implict in any multi keyword search that doesn't include Boolean. Looking at the searches queries that included a Boolean operator, 6% were entered entirely in upper case, implying that the user wasn't conciously invoking a Boolean search.