Although the current multiagent scenario does not allow for communication, there has been some very interesting work done on how heterogeneous agents can nonetheless reach ``agreements,'' or make coinciding choices, if necessary. Humans are able to reach tacit agreements as illustrated by the following scenario:
Imagine that you and a friend need to meet today. You both arrived in Paris yesterday, but you were unable to get in touch to set a time and place. Nevertheless, it is essential that you meet today. Where will you go, and when?Rick Vohra posed this question to an audience of roughly 40 people at the AAAI-95 Fall Symposium on Active Learning: roughly 75% of the people wrote down (with no prior communication) that they would go to the Eifel tower at noon. Thus even without communicating, people are sometimes able to coordinate actions. Apparently features that have been seen or used often present themselves as obvious choices.
In the context of MAS, Fenster et al. define the Focal Point method [26]. They discuss the phenomenon of cultural (or programmed) preferences allowing agents to ``meet'' without communicating. They propose that, all else being equal, agents who need to meet should choose rare or extreme options.
On a similar note, conventions might emerge over time. Walker and Woolridge propose biasing agents towards options that have been chosen, for example, most recently or most frequently in the past [91]. Rather than coming from pre-analysis of the options as in the Focal Point method, conventions emerge over time.