https://emshort.wordpress.com/category/conversation-modeling/Start with older post, adapt from the original format to your custom technique, a lot of advice told there is actually format agnostic. Look for older first and work your way up.
Also all gdc vault lecture to 2014 are now free
http://www.gdcvault.com/freefilter by category, you will find relevant in game narrative (obviously) but also AI, design, production and visual arts!
There is numerous article on gamasutra too
http://www.gamasutra.com/category/design/Games relevant to the question are:
https://promweek.soe.ucsc.edu/https://emshort.wordpress.com/2013/02/26/versu-conversation-implementation/http://www.interactivestory.net/ (look for the paper)
http://gameai.com/wiki/index.php?title=The_Sims (obviously)
Myself have a simple model based on a "formal meter", ie you start as "stranger" and can end up "intimate", each stage build up through interactions until a lock, the lock is resolved through "ritual" (break the ice) that allow moving to the next "formal" stage and specific to that transition level. Affinity is independent as you can be "intimate enemy". Interaction are process through a filter that is "standards" (character's moral compass, evaluate actions) that change depend on "context" (based on a double scale of public space (mall) vs intimate space (toilet) and formal space (work) vs private (home) space yield different result). Standard strength are also modulate by "preferences" (evaluation of attributes) and "personality" traits (responses to events).
From a code point, actions are actually code object that take characters (as data) as inputs into its slots to process the events which is broadcast to all relevant objects (generally inside a room) to let them react back. It allow you to add events and actions agnostic to character, it allow too have specific actions depending on context. Character select actions based on affordances like in the sims.
Ultimately it will depends on the type of game you will make, so the main question are: what is the main progression of the game? what is the function of social within the gameplay? it will shape your requirement