A quick introduction to BLAST

yep, I've become a videoblogger, at least sometimes. See the first video below. Be kind in the comments, this is a new thing for me. This video introduces the different blast programs, discusses word size, and how blastn works, the blastn score and the E value. The treatment is light and not too in depth, but as I said, it's an introduction.
A quick introduction to BLAST from Sandra Porter on Vimeo.