I’ve been reading up a little on the difference between the domains by looking for some examples of each.
According to Wikipedia simple:
The simple / obvious / clear domain represents the “known knowns”. This means that there are rules in place (or best practice), the situation is stable, and the relationship between cause and effect is clear:
An example is following a recipe.
The complicated domain consists of the “known unknowns”. The relationship between cause and effect requires analysis or expertise; there are a range of right answers. The framework recommends “sense–analyze–respond”: assess the facts, analyze, and apply the appropriate good operating practice. According to Stewart: "Here it is possible to work rationally toward a decision, but doing so requires refined judgment and expertise. … This is the province of engineers, surgeons, intelligence analysts, lawyers, and other experts.
The complex domain represents the “unknown unknowns”. Cause and effect can only be deduced in retrospect, and there are no right answers. “Instructive patterns … can emerge,” write Snowden and Boone, “if the leader conducts experiments that are safe to fail.” Cynefin calls this process “probe–sense–respond”.
In casual conversation complicated and complex are often used interchangeably. An example of each is from here A Leader’s Framework for Decision Making
In a complicated context, at least one right answer exists. In a complex context, however, right answers can’t be ferreted out. It’s like the difference between, say, a Ferrari and the Brazilian rainforest. Ferraris are complicated machines, but an expert mechanic can take one apart and reassemble it without changing a thing. The car is static, and the whole is the sum of its parts. The rainforest, on the other hand, is in constant flux—a species becomes extinct, weather patterns change, an agricultural project reroutes a water source—and the whole is far more than the sum of its parts.
Ferraris are complicated, rainforests are complex.