Attention span and learning differ. What you need to do to get your point across cannot be one formula fits all.
Readers - Reads everything/ Does not believe that it is work unless it has prose beyond 250 pages
Skimmers - Can retain 3 points. Needs to be 1 page and should be understood by all. Try the cabby first
Tearers - Cannot read until they criticise it
Discussers - Cannot read or understand unless explained. Usually prolonged discussions
Writers - Most difficult to get the point across - need to contribute to understand
You can do MBTI and other tricks to type cast your boss, but gettng your OWN fundamental definition of the boss is critical to get YOUR message across.