On March 2nd I wrote an article for the Federated Search Blog: On credibility of search results. 
The article asserts that a federated search engine is only as good as the quality of the content to which it provides access. While the major consumer-oriented search engines may provide more search results overall, it is left to the user of the search application to sift through the search results to identify which content represents credible scientific and technical information.
OSTI doesn't suffer from this quality issue. As stewards for DOE research output, OSTI only disseminates the most credible information. Below are just a few examples of OSTI's commitment to providing only vetted quality information via its federated search applications.
ScienceAccelerator.gov  provides access to only credible information via federated search; ScienceAccelerator.gov empowers researchers and the science attentive citizen to search important information resources of the U.S. Department of Energy's (DOE's) scientific and technical information.
Beyond DOE, Science.gov delivers 200 million pages of authoritative U.S. government science information from 14 federal agencies that participate in the Science.gov Alliance .
At the global level, WorldWideScience.org  serves as a worldwide science portal to the most credible information from international government agencies and from organizations sanctioned by their governments.
As OSTI grows and the scientific and technical information we provide expands, the quality of information we provide will always remain high.