As a physician who specializes in difficult cases, maybe I can provide a slightly different perspective: What Google has done with Google Scholar has been to incorporate the PUBMED database (a database of all scholarly journals) as well as the database of OMIM (a database of inherited diseases) into its search protocol. Physicains (including myself) often will use the above two databases for aiding in the diagnosis of specific disease. You will also notice that the proper use of terminology helps (for example, the use of the term "nyctalopia" instead of the more common term "night-blindness") will help eliminate some common misconceptions. As the google search term is based on linkage, it may actually place the truly unusual diagnoses at the bottom of the list - To be fair to the public databases that have been instrumental in advancing American scientific progress (both the above databases are public domain as they are setup and run by the National Library of Medicine), the study cited above would be truly illustrative if it actually did a comparison between Google results and Pubmed results (www.pubmed.org).