Purposefulness - whether somethings intended function matches its actual function
Quality - somethings forms synergize to a purpose that is greater than the sum of its individual elements - somrthings form functions toward its intended purpose with no other elements of its form detracting from or remaining inert toward its intended purpose
Most of the time you cannot envision a quality product unless you have already observed a quality reference
When making something new, instead follow a set of rules whose output produces quailty
Rule 1 - No more, no less - evaluate the function and make the form match
Rule 2 - Ease of use - form should be familiar but complete the function with as little thought toward the form as possible
Rule 3 - Granular contrast - form elements can clearly be divided but whose sum creates a non-contrast flow or information
Rule 4 - Balance - Phi - visual elements balance to reduce "overall contrast & disbalanace" to produce controlled contrast creating points of interest that drive information flow