# Defining your Simulation

A Truman simulation is the simulated social media environment that a research participant experiences.

Each individual Truman simulation is based around the moment the participant joins the site. T₀ is when they joined. Every post, comment, or actor behavior on the site is in reference to this point in time. For example, a behavior can be defined to happen at -12:30, which is 12 hours and 30 minutes before they joined, or 62:31, which is 62 hours and 31 minutes after they joined.

As a result, participants will always receive the same Truman Simulation (negating any manipulations based on experimental conditions and the participant's own posting behavior) since the simulation is based on the relative time to when a participant created their account and not based on absolute time. Therefore, you will also have many parallel simulations during the study.
