monica aresta's Profile

There are a couple of things that make patterns distinct from other forms of design guidance. One is that they are routed in practice – they are not simply “good ideas” or theories (not that there is anything wrong with those) but they are drawn from real examples of things that have worked to solve problems in specific contexts. Another is that they cannot just be based on a single example – a pattern can only really be called a pattern if it can be demonstrated to have worked in at least three distinct cases. We call this the rule of three. We recently reviewed all the “patterns” that have arisen from our workshops and most fall into the “candidate pattern” category – we think they might be patterns, we have one – occasionally two examples of the pattern – but we don’t yet have sufficient evidence to be confident that this really is a pattern.

Another is that they cannot just be based on a single example – a pattern can only really be called a pattern if it can be demonstrated to have worked in at least three distinct cases

We call this the rule of three