Sensitivity Analysis

The Sensitivity Analysis module of SocLab allows to perform sensitivity analysis about one or several organization’s structural parameters or  Actors’ psycho-cognitive parameters. This page focuses on the usage of this module.

Preliminary clarifications

Sensitivity analysis is about to make some of the parameters vary from a experiment to another, in order to cease its influence on the results. A sensitivity analysis (or Experience in SocLab GUI)is a replication of simulation experiments.
A simulation experiment consists in several runs , each one lasting up to a certain number of steps. From a simulation experiment to another, some parameters whose influence is under study vary. They’re called Experiences Parameters in SocLab GUI.

Launching Sensitivity Analysis

This module is launched via the  Sensitivity Sensitivity Explorer  menu. Sensitivity Analysis module’s aspect is very similar to the Simulation module. See the Simulations section for the description of the elements they share. The main difference between  a sensitivity analysis experiment and a simulation experiment are:

  • Number of Experiences : The number of simulation experiments (i.e. a certain number runs, each one lasting  a certain number of steps) to be performed. Between two simulation experiments, the selected parameters vary within in the intervals defined in the parameters tabs (see next section).
  • Run : initiate the sensitivity analysis. Results are stored in a specific folder called Sensitivity , whose path can be chosen.
  • To open previous sensitivity analysis results, look for the file named as <model_name>_SensitivityInitialParameters.xls in the Sensitivity folder.

Selecting Experience’s parameters

The Experience's Parameters tab is where the parameters who will vary between each simulation experiment are selected.

parameteres selection

Parameters selction (click to enlarge)

There are three categories of parameters to be selected:

  • Simu Parameters are the psycho-cognitive parameters of Actors rationality (see Simulations section). Parameters variation can be applied for every Actor (the whole
    item), or each Actor separately.
  • theStakes that each actor (selected in Actors cell) put on each relation (selected in Relations cell).
  • the Solidarities of an actor (selected in the Actors cell) towards another (selected in the Solidarities cell).

Parameters whose sensitivity are to be studied are added or removed to the right panel list using right and left arrows buttons. For each parameters added to the list, the bounds of its interval within which it varies can be defined. First simulation experiment begin with the minimum value, second with the maximum value and the others with random values within the interval.

Don’t forget to click the accept button before you run the sensitivity analysis,  to validate the list of varying parameters.

Viewing Results

  • Option Actor : graphs show variation of average Satisfaction obtained during simulation experiments (on y-axis) according to one of the following, on x-axis : selected varying parameters value  OR  the average number of steps.
  • Option Relation behaves likewise, with relations states values instead of Satisfactions.

N.B. To retrieve the details of a specific run, launch the Simulation module and browse the Sensitivity folder.  All the simulation experiments folders are stored in this folder. By opening the <model_name>SimulationInitialParameteres.xls file, you’ll be able to retrieve the precise parametrization of a given experiment and plot the simulation results as usual.