The field of study surrounding interactive storytelling encompasses many disparate fields, including psychology, sociology, cognitive science, linguistics, natural language processing, user interface design, computer science, and emergent intelligence. They fall under the umbrella term of Human-Computer Interaction (HCI), at the intersection of hard science and the humanities. The difficulty of producing an effective interactive storytelling system is attributed to the ideological division between professionals in each field: artists have trouble constraining themselves to logical and linear systems and programmers are disinclined to appreciate or incorporate the abstract and unproven concepts of the humanities.