By making clear the intended outcomes and the causal pathways leading to them, a program logic model provides the basis upon which planners and evaluators can develop a measurement plan and adequate instruments. Instead of only looking at the outcome progress, planners can open the "black box" and examine if the intermediate outcomes progress as planned. In addition, the pathways of numerous outcomes are still largely misunderstood due their complexity, their unpredictability and lack of scientific / practical evidences. Therefore, with proper research design, one may not only assess the progress of intermediate outcomes, but evaluate as well if the program theory of change is accurate, i.e. is successful change of an intermediate outcomes provokes the hypothesized subsequent effects in the causal pathway. Finally, outcomes may easily be achieved through processes independent of the program and an evaluation of those outcomes would suggest program success when in fact external outputs were responsible for the outcomes.