An e-mail from Matt...
Jae: skimming through your initial content on your blog pages...
Sub-group membership seems a key concept/challenge for me...
I wonder about whether "subgroupings" as categories are sometimes fixed and sometimes dynamic, depending on the qualities of a given group of people. There should be a name for this attribute of a crowd: how dynamic its subgroups are.
-"Subgroups" might be an emergent quality, or not... dependent on group.
Words I don't fully understand that need a working definition: crowd, group, subgroup.
One way to look at this would just be as sets. Sets have sub-sets. subsets may or may not overlap. set theory...
BUT, I also wonder about whether set membership is a Universal Truth, or is in the eye of the beholder, context dependent, etc. e.g. Each person in the room avoids the subset of ugly people and moves toward the center of the subset of attractive people, where these subsets are relative to each individual and may shift depending on context.
(other subjective qualities: dangerous, fast, large, etc...)
-matt
Yes! Good points.
ReplyDeleteWe need to define some sort of working terminology for groups, sub-groups, etc. Set theory would be a convenient way to describe the group membership of individuals, especially when it comes time to write down our ideas on paper with precise mathematical notation.
Here's my current train of thought on groups for evoDesign crowd purposes:
Crowd = the entire set of individuals contained in one phenotype
Group (defn. A) = a subset of a crowd (could contain the entire crowd) where the behaviors of all the individuals at a given moment in time are defined by the same set of genes -- i.e. these five guys have a flee value of 0.3, a hide value of 0.5, and a wander value of 0.2 so they are behaving like prey.
Group (defn. B) = the same as defn. A, but instead of just sharing the same behavior state an any given moment, the individuals in this type group would have the exact same state diagram and behavior gene makeup
Group (defn. C) = a subset of a crowd defined by locality -- i.e. those 3 guys over there in the corner.
I think we need all 3 notions of group defined above, but obviously we shouldn't use the word "group" for all three meanings. Any ideas on what we could call these three different meanings of the word group? Are there other possible definitions y'all can think of?
Group (defn. B) is definitely static. Groups (defn. A+C) have dynamic membership, which is interesting, especially when we start talking about behaviors defined by locality or interaction with other groups. One think to think about with regard to the dynamism of a particular group is explicitness vs. implicitness. Is the dynamic nature of the group membership defined by a variable or does it emerge from the interaction of a lot of behavior variables among a couple of groups? My guess is probably the latter and this is one of the things that makes crowd sim really interesting to watch! Thoughts?