This section describes the steps required to set up a probability distribution for an uncertain input parameter. We will use the project closed_homogeneous__transient.ckprj from the samples<release_number> directory to illustrate the various options that are available. These instructions assume that you are already familiar with the Parameter Study facility as described in Using the Parameter Study Facility and the Pre-processing and Reactor Properties panels described in Setting up a Parameter Study in Chemkin Getting Started Guide. The sub-sections Opening an Uncertainty Analysis Dialog for Chemistry Properties—Opening an Uncertainty Analysis Dialog for Species-specific Properties below describe how to get to the uncertainty-analysis dialog from the interface for different types of input parameters. Setting up a Probability Distribution for an Uncertain Input Parameter then describes how to supply the distribution characteristics for the selected input, once in the uncertainty-analysis dialog and how to complete the remaining uncertainty-analysis set-up.