That's why subjects are a convenient mode of organization for them. But teaching skills in labs apart from facts and cases tends to confuse students, and kills off their motivation for learning the skill. Likewise, teaching subject matter apart from the relevant skills is a bad idea because students find it difficult to use the subject matter in a context different than that in which they learned it. Many view history, for example, as a set of cases and facts, but this view ignores the skills that history packages, and drains the life and most of the value from it. The problems with subjects, however, go far beyond the artificial distinction between lecture and lab.
Subjects keep schools from effectively tying education into students' lives.
Some examples are politics, trucks, and animals. A domain is, like a subject, a collection of skills, cases, and facts. Domains, however, have a much more eclectic mode of organization. Domains organize things according to how they cluster in everyday human experience. Domains have three interesting properties.