"A theory of change is a concise, explicit explanation of: "If we do X, and Y holds true, then we'll achieve Z because a, b, and c." With this structure, the TOC makes clear how (if-then) and why (because) the project team expects or assumes that certain actions will produce desired changes for individuals, groups, communities or institutions in the environment where the project will be implemented. TOCs can be developed for different levels of the objectives hierarchy. A "high level" TOC articulates how successful achievement of the project's end-of-project objectives or outcomes (SOs) will be contributing to longer-term, broader, lasting change (project's goal). However, often TOCs are developed to describe the whole causal chain - from activities to outputs, from outputs to IRs, from IRs to SOs, and SOs to goal. In this case, the TOC typically splits into complementary "if-then-because" statements that focus on the changes that the design team is least certain about - where assumptions are greater, or evidence is less strong. Presenting a more comprehensive, multi-level TOC enables the design team to investigate and explain the interaction between various activities or strategies; in other words, it helps describe pathways of change. Pathways of change identify the connections between different preconditions, and how they relate to or mutually reinforce each other, and describe the sequence in which they are to be achieved." (Page 3)