This one is interesting, but not surprising. GG describes describes Google's stemming as "some stemming" and then says that it is better to have the actual word on the page. Does that mean that webmasters still have to optimize for all word forms?
[Link to quote
Industry-specific terms, slang terms, precise terms, and sloppy terms. Check out your logs to see what users are typing. If users are typing
configure my widget
compile my widget
then you'll want to make sure you also mention widget configuration, reconfiguring your widget, widget compile errors, widget customization, etc. The spread of words that 100 people will use when they have the same information need is staggering. Be thinking about what queries your missing because your page has the word "configure" but not the word "configuration." Note that Google does some of this semantic analysis (e.g. some stemming), but it's better to find the words from your own pages instead of Google having to guess that your "compile" page also deals with "recompilation."