Today, the vast majority of websites are still designed and built by talented generalists, and there’s absolutely nothing wrong with that. It’s just that some of the larger and more complex sites do require composite teams of specialists with a singular focus. Experts in information categorisation, human computer interaction or interface design. They also need people who specialise in specific programming languages, databases, security, or application architecture. The history of all human progress can be counted by the increased specialisation of individuals amongst a group, and I see this as a good thing.
So we have this strange dichotomy that the term webdesign can be used to describe both a novice and an expert, a neophyte and a master. This is where the Dunning-Kruger effect comes in. If you’re not familiar with this concept it’s the observation that novices suffer from the illusion of superiority and tend to rate their skills much higher than experts because they don’t fully understand the breadth of the field they need to master. Or to use a much quoted aphorism, “they know what they know, but they don’t know what they don’t know”. By comparison, experts tend to know more, but are also more conscious about what they don’t know, hence making them less sure about their expertise.
— From Andy Budd’s What’s in a name: The duality of user experience