agents from the groups with the least number of participants interact.

-   \[s:hb\] Deep hierarchy: Each turn $g-1$ agents join to the group with largest number of participants (that is, there is only one group to which each turn $g-1$ agents join).

-   \[s:hc\] Random hierarchy: Each turn $g$ random agents interact.

Above, by participants we understand the total number of individuals that were merged into an agent.

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   ![Diagram of the interaction ordering for aggregation schemes for $g=2$: Shallow Scheme — each turn two agents from the least numerous groups interact, Deep Scheme — each turn a single participant joins the previously formed group.[]{data-label="fig:aggregab"}](aggregation_a.pdf "fig:"){width="45.00000%"}   ![Diagram of the interaction ordering for aggregation schemes for $g=2$: Shallow Scheme — each turn two agents from the least numerous groups interact, Deep Scheme — each turn a single participant joins the previously formed group.[]{data-label="fig:aggregab"}](aggregation_b.pdf "fig:"){width="45.00000%"}
                                                                                                                                                     Shallow Scheme                                                                                                                                                                                                                                                                                                        Deep Scheme
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For some models, the way in which groups are formed is irrelevant for obvious reasons. This is the case for Random Responder, Best Decides, Direct Signal Sharing and Truth Wins. The result is always the same and is equivalent to the simplest situation without any hierarchy. The models, which are 