Session 5-30

After the last session, I feel like I should shift my focus a bit back to the theoretical side of the endeavor. I will spend some time going through the entries available through the WSC07 archive and see if I can find some relevant stuff.

Note (while I'm back to literature research): DOI numbers - so far I didn't find them for ANY of my source papers. Either I'm being stupid here, or the system isn't nearly as universal as Paolo made it sound. Anyways, getting the formalities right has a relaitevly low priority right now. I'll see what I can get done on the run, and leave the rest for later.

Minutes 5-29

Meeting in Paolo’s office, today at 14:30. List of major topics and findings follows:

• We discussed the model overview and its 4 stages/levels: the environment, the modifiers („Personality Traits“, „Internal Variables“), the Variables („influenced by perception“), and the behavior.

• I could not provide convincing arguments as to the nature of the individual variables being [0,1] intervals, other than it representing a first working assumption. This should be clarified in future versions.

• The role of the modifiers (obviously my term; I’ll just stick to it until I can decide on something more fitting) was discussed, especially regarding their natures definitions as compared to other terms and constructs commonly used to describe personalities (e.g. those of „the Big five“). It might be worthwhile to get a better overview here, but all in all I got the impression that I was on the right track here, especially after discussing the conceptual closeness of my „insecurity“ and „leadership“ terms with the notions „status“ and „power“. Still, from the theoretical background point of view it would be nice to be able to provide some alternatives here.

• Another important topic was my (intuitive? At least somewhat unreflected) inclusion of a decay mechanic within the handling of an agent’s arousal level. Paolo was right here in assuming that I merely included it in the first place because, well, I felt that merely increasing an important variable like that over time would not represent a very natural process. I will have to see if I can somehow back up either approach with some literature, but I must confess that I am now intrigued to go with an unrestrained arousal level first; I quite liked the idea of “Gefangensein in einem Zustand”. Otherwise, a more concrete theory of how disengagement actually works could be helpful. Tony Higgins was named as a possible source.

• Also mentioned was the problem of consistency (and therefore the possible occurance of dithering), which is not currently explicitly addressed in the model (that is, agents show little consistency in their states other than that introduced by the fact of small step changes). I’ve taken the hint that I should probably think about the implementation of some more explicit and endogenous mechanism to handle this, like some kind of “momentum” of change. Right now, however, I feel like this has a relatively low priority, since said mechanism could probably be built on the current handling, which (while maybe not being perfect with regard to artifacts) still provides some basic functionality.

• Also discussed were more technical aspects of the programming environment, such as the possibility to include external functions (Java,…), and the importance of wrappers to analyze over multiple runs (something that I will definitely look into once the analysis moves into main focus).

• Finally, the last (but certainly not least) major topic was literature, where I agreed to do further background research (“persons/institutions/journals”) on the existing bibliography. In addition, Paolo showed me two new (and apparently promising) sources for papers, namely the ACM/WSC ’07 (several landmark papers and tutorials) and BRIMS/SISO ’07 (emphasis on list of recommended readings).

Session 5-28

Going to work on a number of smaller things today. Main goal is to rework the existing modifiers, and finally introduce the one that handles the aggression level.

Raw Stream:

Session 5-28 Opened (Programming)

Review existing code & notes ("getting back into the mindset")... DONE
Implementing the "perception range slider" (so far, I was using "in-range" to crudely simulate the limited perception/action radius of individual agents, with values picked more or less randomly. A centralized way to control this could be helpful, though.) ... playing around with parameters a bit, seems to work nicely... DONE
Add an additional color to indicate violent behavior in different blocks... DONE
Implement a behavior function SKELETON for support...
SUB Think about mechanics of support behavior (scribble break)
... DONE
Implement a behavior function SKELETON for "spectating" (default)... DONE
Rework modify-safety function ...
SUB introduce ratio into calc... POSTPONED (need a better way to handle ratios first; I'll think about this later)
SUB take acts of hostile violence into account (they shout decrease an agent's safety level somewhat, or even more if the hostiles have an advantage in numbers) ... DONE
SUB make safety a value between 0 and 1 ... DONE

-SALAD BREAK- ... BACK

Test new modify-safety function... seems OKAY.

Add to the arousal-modifier: density-dependant increase... DONE. For now I ended up using this: 4 agents per patch are "normal" (no modification), everything above increases the 0-1 arousal value by (n-4)/10.

Implement aggression-level modifier/handling ... LEFT FOR TOMORROW.


Session closed.

It became pretty late; seems like I'll have to leave the agression-level handling for tomorrow. Other than that, things seemed to come along nicely.

Bibliography

Work in progress...

Postmes, R.; Spears, R. (1998) Deindividuation and Antinormative Behavior: A Meta-Analysis. Psychological Bulletin.
http://psy.ex.ac.uk/~tpostmes/PDF/postmesspearsPcychBull98.pdf

Haddock, D.D.; Polsby, D.D. (1994) Understanding Riots. Cato Journal. Volume 14, Number 1.
http://www.cato.org/pubs/journal/cj14n1-13.html

Russel, G. (1998) The Anatomy of a Riot. Psychology Today, Nov/Dec 98.
http://psychologytoday.com/articles/pto-19981101-000017.html

Reicher, S. (2001) The Psychology of Crowd Dynamics. Blackwell.
http://www.uni-kiel.de/psychologie/ispp/doc_upload/Reicher_crowd%20dynamics.pdf

Wijermans, N.; Jorna, R.; Jager, W.; van Vliet, T. (2007) Modelling Crowd Dynamics: Influence factors related to the probability of a riot http://www.rug.nl/staff/w.jager/Wijermans_ESSA_2007.pdf

Jager, Popping, van de Sande: Clustering and Fighting in Two-party crowds (2001)
Journal of Artificial Societies and Social Simulation, 2001
http://jasss.soc.surrey.ac.uk/4/3/7.html

Hello, World!

Moved the Journal to this platform. The plan is to keep an up-to-date bibliography here, as well as the regular "done-this-and-that"-style and/or reflective journal entries. I'm still looking for a convenient way to keep an updated version of the program code accessible from this site, but we'll see about that.