If the SAMR model is new to you here is a brief explanation of the four letters that make it up:
S- Substitution - Tech acts as a direct tool substitute, with no functional change.
A - Augmentation - Tech acts as a direct tool substitute, with functional improvement.
M- Modification - Tech allows for significant task redesign.
R - Redefinition - Tech allows for the creation of new tasks, previously inconceivable.
The SAMR Model begins with Substitution (as in read the poster from the bottom up to more clearly understand the model), moving to Augmentation, then Modification and finishing with Redefinition.
The SAMR model is the work of Ruben R. Puentedura, Ph.D. from M.I.T. For more information on the SAMR model check out his website at http://hippasus.com/rrpweblog/.
For an indepth look you may want to check out the presentation from August 23, 2012 with the title "The SAMR Model: Background and Exemplars."
Via Beth Dichter