Lesson 3.2: FiletypeAccess Lesson 3.2 slides hereIn the last lesson, you explored the site: operator.The next most common operator is called filetype:. Just as site: limited your results topages within a particular website, this is the way of limiting your results to files anddocuments of a particular kind.There are lots of different kinds of documents out there, including PDF files, flash files(SWF), Google Earth files (KML), Excel files (XLS), and more. A lot of manuals, forexample, will be in PDF format.Each type of file has an official three or four letter extension which tell you what kind ofdocument they are (e.g., PPT, PDF, DOCX). There may be some filetypes or fileextensions you may not know about, for example, CSV and DAT are commonly used torepresent globs of data that are out there in the world.CSV stands for comma-separated values, and it is a file type that is used to store largedata sets. What that means is that you can go find a CSV on a particular kind of dataand then download that data set and work with it. There are some others you might nothave encountered before--for example, KMZ, which is one of two file types used in theGoogle Earth product.One thing to remember about filetype: is that you can use it in combination with site:.So, if you say [site:stanford.edu filetype:pdf], you will get results that meet both of thosecriteria:
Try that KML extension from Google Earth. The way filetype works is you simply type[filetype:kml]. So, if you want to look for something like information on the Lewis andClark Expedition in Google Earth you would use: [lewis clark expedition filetype:kml]:
Once you get these results, what do you do with a KML file? Well, one thing you can dois to download it. You can right-click on the title and select "Save link as," which willdownload the file to your computer. You can then upload it into Google Earth or use it inother ways.Note that each of the results blocks in the image above has a link that says "View inGoogle Maps." Any time you see a link that says "View on" or "View as," you have theopportunity to download it into Google Maps and get a view of it. This wont be the sameas looking at it in Google Earth, but its a pretty good preview.
Another instance in which you would use the filetype: operator would be if you wantedto find massive data sets on tax rates, focusing on those CSV files. In that case, youmight use a query like: [filetype:csv tax rate]. You could further limit this search to CSVfiles on tax rates from the New Jersey government like this: [filetype:csv tax ratesite:nj.gov].