"You can use a free Blendspace account to create linear lessons for up to 35 students to guide students through basic content. For instance, a middle school Biology teacher could create a canvas about photosynthesis and upload images and videos, plus their own text to help build student knowledge. You can also quiz students as they move through material using Blendspace's multiple choice quiz builder. Using the embed code and share links provided by Blendspace for each canvas, you're also able to add a canvas to your classroom website or to an Learning Management System like Edmodo. Teachers can also ask students to remix canvases or create their own. These canvases could be shared with the rest of the class for feedback or for homework review purposes. However, these remixes aren't necessarily a valid form of assessment, as a lesson can be cobbled together from online content without having to know much about the topic. You can make use of the gallery of canvases available to teachers who may want ideas. With a paid account, you can ask students to collaborate on lessons. Blendspace can be a great addition to the classroom, but it doesn't replace instruction."
Jim Lerman's insight:
This review by graphite tends to focus more on Blendspace's limitations than its strengths. The interface is simple to use and helps teachers, or students, to create multimedia presos quickly. However, as pointed out, the presos lead to learning that is quite linear. That having been said, teachers who have responded have rated Blendspace quite highly.
Blendspace has very recently been upgraded (Feb. 2014) with numerous improved features. See description on their blog