Your equation, taken as a heuristic, is quite good and illustrates that usability (or user experience) is multi-dimensional. This heuristic equation will have different terms for different categories of product, but it makes the point that we should be more specific when we speak of "the usability of the product".
There is an equation called "Baker's Equation" that is somewhat similar, but focused on the liklihood of success of assistive technologies. S = M/(P+C+L+T) Where S = Liklihood of success M = disabled person's motivation to complete a task P = the physical effort required to complete a task C = the cognitive effort required to complete a task L = the linguistic effort required to complete a task T = The amount of time required to activate and control a device. Chauncey > Take > findability + accessibility + predictability = usability, > > But add in emotional appeal, because as we all know, having read Norman's > Emotional Design, that products, services, things, that garner an emotional > response, people consider more usabile, whether they are - or not. > > And from Peter: > "The 'j' factor was inspired by Milton Glaser's life lesson #5... which > beautifully offers that "Less is not necessarily More", rather... > > "Just enough is More" > > 'Just enough' of what matters to our lives so that the experience feels > wonderfully satisfying. In life, there never is a set formula." > > f(j)+a(j)+p(j)/l + e(1-c)= u > > e = emotional appeal > f = findability > p = predictability > l = learnability > c = cost > ________________________________________________________________ Welcome to the Interaction Design Association (IxDA)! To post to this list ....... [EMAIL PROTECTED] Unsubscribe ................ http://www.ixda.org/unsubscribe List Guidelines ............ http://www.ixda.org/guidelines List Help .................. http://www.ixda.org/help
