Van der Heijden defined perceived enjoyment as "the level to which the activity of using a particular system or service is perceived as being nice and enjoyable" [42], and indicate that perceived enjoyment is a key determinant of users' attitudes and experiences in using a hedonic information ...
3. Testing the Keystone Theory in Social-Ecological Systems The Hawaiian Social-Ecological System as a Model There are countless social-ecological systems that could be chosen from around the world to model the theories explored in this paper, but in order to test the conceptual validity of ...