While it is possible to get worm densities up to as much as 20 kg/m 2 or 4 lbs per square foot (Edwards, 1999), the most common densities for vermicomposting are between 5 and 10 kg/m 2 (1 to 2 lbs per ft 2).
A massive open online course (MOOC) is a model for delivering learning content online to any person who wants to take a course, with no limit on attendance. A short video about MOOCs and the connected age. Recent Spotlight.
Define 'MOOC'. The author of this book on crowdsourcing took a bold move in trying to define the term in a way that would make it clear when one entity (like the t-shirt company Threadless) should be considered an example of the phenomenon while another (like Wikipedia) should not.