Each one of the Hypothesis modeling and evaluation Tools captures several assumptions about your project. The Assumptions Manager Tool provides a single place where you can view, organize, and prioritize all the assumptions upon which your project is based. Once you have selected a set of prioritized assumptions to focus on, the Evidence Gathering Tool is where you define experiments or evidence gathering activities to increase your confidence or reduce the uncertainty in your assumptions.
The goal of experimentation and evidence gathering is to increase confidence in the assumptions that the project is based on and reduce risk and uncertainty in the project opportunity modeling and risk analysis.
Whether you realize it or not, any innovation idea or concept is based on a lot of assumptions and areas of uncertainty. Some you may be consciously identifying as assumptions and others you many not. The Hypothesis modeling and evaluation tools are intended to help make more of those assumptions explicit and to the extent possible, attempt to assess the impact they may have on the viability of the idea.
When making decisions about investing in a project decision makers need to understand the risk involved in that decision. Risk is directly correlated with the uncertainty associated with assumptions. Reducing the uncertainty of key assumptions therefore helps reduce the project risk as well.
Narrowing the range of uncertainties in quantitative models helps increase their accuracy (which may either support or contradict your desired outcome).