It's pretty capacious – everything from time management techniques to the willpower apps beloved of Rationalists to meditation might be seen as a form of MCSE. But I tend to mean something a bit more particular – the crafting of software to support or transform human thought processes (see Media Science Heroes).
Some notable Media Science Heroes, that is, people who pioneered the use of technology to enhance and extend the processes of human thought. This is an incomplete list and maybe focuses too much on individuals – eg, many people contributed to the Logo and Smalltalk and their associated schools of thought, not just Papert and Kay. But if I were to teach a course on Media Science these folks would make up a good chunk of the syllabus.