Display size study

More than half of students (58%) in a recent study couldn't read content displayed on a 70-inch flat panel in an average-sized classroom. The findings are consistent with the 4/6/8 Rule for display size recommendations, a "long-standing guideline commonly used by AV integrators and installers for determining the appropriate sized displays for different environments," as well as the InfoComm DISCAS draft standard, according to a press release. "Using the DISCAS draft standard to calculate the Farthest Viewing Distance for Basic Decision Making, a 70-inch display would not be recommended for viewing text-based educational content at distances of approximately 18 feet and beyond."
(2016). Choosing the right classroom display.  EPSON.
http://www.epson.com/cgi-bin/Store/jsp/Landing/education-classroom-projector-display-size-vs-flat-screens.do?ref=van:us-classroomdisplaysize