Lex Parsimoniae is Latin for " Law of Parsimony ", which slipped out into its simplest form is the Law of what can be spared, should.
This is a theory that I have been studying for the past year and through observation believes that this can be applied to all situations that require a more efficient, functional solution. This paradigm has many names, but is best know as Occam's Razor. His razor suggests that when resources are limited or when speed of function is essential, design / complexity trade-offs should be based on what does the least harm to the probability of success, however that is defined.
Form is Function
There is a school of thought that beauty in design results in good function, but I prefer to subscribe the fact that just concentration on the functionality will by its very nature, create its own aura of design. Sometimes, the focus on functional efficiency inspires a feeling that goes beyond aesthetics and extremely give us the sense that its form is of a higher echelon.
Barrier To Entry
The brain is an amazing piece of kit. One of its most amazing functions is its ability to optimize when processing data. Each brain has been traced over many years (or maybe it inherently has the ability) to simplify individual objects into groups. Instead of seeing each individual blade of grass, the mind sees a field. Millions of pieces of data grouped into one object because it knows, to comprehend millions of pieces of grass would take and severe amount of effect. Effect that could be focused elsewhere. So it generalises to make life easier. This sort of information overload can happen in design as well; Too much will distract from your very objective. Remember that 7 Second Rule? If your web app or website has 7 seconds to impress then would not you prefer showing off your functional muscles? How useful your app is? and not long it takes to load the really cool (bandwidth crunching) design? Remember how easy it is to make your mind up about someone when you them for the first time. Same rules apply.
Just Do It!
"entia non sunt multiplicanda praeter necessityitem", or "entities should not be multiplied beyond necessity"
Egypt just remember, KISS – Keep it Simple, Stupid!