This is a demo of a Google Linked CSE (Custom Search Engine) service. Linked CSEs search over domains and pages that are specified in a file that defines the particular instance of the CSE. In this example, the links (to pages and domains) that are searched over by the CSE are extracted on-the-fly from the appropriate OpenLearn unit XML document, providing a custom search engine that will search over the pages and domains linked to from the particular course, as well as over the whole of OpenLearn).
Each OpenLearn unit thus in principle can be used to define a custom search engine on the subject area covered by the unit *if* the unit contains links to appropriate 3rd party websites.
This approach is easily generalised, for example to using lists of links relating to a course pulled from the OU ROUTES service, or lists of links on a particular subject area pulled from Intute.
To search over sites referenced from a particular Openlearn unit, go to http://ouseful.open.ac.uk/openlearnplayground/openlearncse.php?cc=openlearnUnitCode (eg http://ouseful.open.ac.uk/openlearnplayground/openlearncse.php?cc=T180 for T180_8).