In his standard work on aspect , the linguist Bernard Comrie distinguishes two forms of time reference in language - aspect and tense. Tense ‘relates the time of the situation ... to some other time, usually to the moment of speaking’, whereas aspects are ‘different ways of viewing the internal temporal constituency of a situation’. Where tense distinguishes between situations taking place in the past, present or future, aspect draws a distinction between the perfective ; a situation viewed from the ‘outside’ as completed, and the imperfective; a situation viewed from the ‘inside’ as ongoing. The shift from narrative representation to interactive representation entails an aspectual shift like that from perfective to imperfective, from outside to inside the time of the situation being described. Narrative representation can thus be considered as analogous to the perfective aspect - always already completed by closure, apprehended as a totality as if seen from a distance and without the possibility of change, whereas interactive representation is analogous to the imperfective aspect - incomplete, seen from the inside with all the messiness and incoherence that this implies, ongoing.
It is important to recognize that aspect does not distinguish between different types of situation but between different ways of representing a situation, or more precisely between different ways of positioning the audience with respect to a situation. This suggests that perfective and imperfective aspect, and by analogy linear narrative and interactive simulations, correspond to two fundementally different modes of spectatorship.
If a story refers to a chain of events that have already taken place, that have been completed in some sense before the story begins (otherwise how could one tell a story about them?) what might an interactive story or simulation refer to? An interactive simulation appears to designate the conditions for events rather than the events themselves. The interactive simulation sketches a web of possibilities and constitutes a system for producing story events in time - a story engine. Closure - the cutting out and sequencing of events from the mass of possibilities - is effected by the spectator, albeit within a framework of conditions and possibilities designed by the author.
It is in the differing aspect of their respective modes of closure that we can locate the apparent disjuncture between the nature of interactivity and that of narrative. The moment the reader intervenes to change the story (at the nodes of multi-linear narrative or at every moment in a spatio-temporal simulator) is the moment when the story changes from being an account of events which have already taken place to the experience of events which are taking place in the present. Perfective becomes imperfective, story time becomes real time, an account becomes an experience, the spectator or reader becomes a participant or player, and the narrative begins to ressemble a game.