Internal characteristics

Internal characteristics is part of the Cognitive architecture.

Forgetting model

The counterpart of learning is forgetting. Agents may forget knowledge or information if they are not solicited during the simulation. Using a bit of knowledge during a step is enough to be sure that this bit will not be forget today. Forgetting has different modes:

  • it could be random
  • based on the age of the information

Randomly selected

You define a probability to forget, combined with the length of the knowledge, it will define the number of bits that will be forget during the day. If this rate = 0, agent will forget any bits of knowledge; if rate =1, every bit will be affected by the knowledge.


If you don’t use Symu, with a forgetting rate of 0.1, you may loose 0.1* 20 bits = 2 bits of knowledge today.

Standard deviation define the level of randomness you want around the forgetting rate.

Oldest knowledge

If the oldest knowledge mode is selected, only the oldest knowledge is eligible to be forgotten. It is based on it’s TimeToLive parameter. If set to -1, information will last during the simulation, otherwise it is compared with the age if the information to decide to forget it or not.

Partial forgetting

Then you must define the how every bit of knowledge is affected. If partial forgetting is chosen, the partial forgetting rate define how much an agent loose at each step, otherwise, the bit is completely forgotten. You can define the minimum level of information that left for each bit.

Risk aversion

The risk aversion parameter affects whether or not an agent can make a particular decision. The risk aversion parameter prevent an agent from acting on a particular belief. Agents who are risk averse will still be able to communicate their knowledge and beliefs like any other agent, but will never be able to make the corresponding decision.