Evolution of expertise refers to the slow transformation of competences, know-how, education, and skills that the people working in specific field possess. There are three specific reasons for this constant evolution of expertise.

First is the change in customers' expectations and needs. Every generation of customers has new types of needs.Customers learn to expect certain basic level of quality or know-how, and year by year they start to expect new types of things.

Second is the change in technology and technics that are available to be used in the field. For instance the development of ICT brings new competence requirements to almost all knowledge intensive fields almost every year. What are the basic technologies and technics that beginners need to handle, and what are the really esteemed technologies and technics that only an expert is expected to handle, change in every generation.

Third is the change in labour markets and in society. The rules, markets, competition, foundations of education, processes and structures of the society are in constant change. New branches of expertise and professionals start to cooperate with the people in the field, and people with new types of educational and vocational backgrounds start to enter the field. They bring new types of practices and methods along. Furthermore, even the whole extension and definition of the filed is changing. In many fields, the answers to guestions, what are the new and old branches of the field, where are the centres and peripheries of the field, what things are underground or in interphases of the field, who are the true professionals of the field, and what kind are their usual backgrounds, change in every generation. That is what we call evolution of expertise.