The direct interest can change from a child's interest in dogs to an adult's interest in behavioral psychology

Interest in a domain can vacillate between direct interest and indirect interest (Dewey, 1913).  While a young girl with a direct interest in dogs may be indirectly interested in dog training techniques, these interests may evolve as she matures; she may become directly interested in animal training and behaviorism studies, while becoming indirectly interested in domesticated animals.  Likewise, a student who is allowed to pursue direct interests in STEM classrooms will have an indirect interest in learning STEM as a means of pursuing their direct interest.  The indirect interest in STEM might evolve into a direct interest.