The Good Enough Guide is intended for field-based project officers and managers. It aims to help them make impact measurement and accountability become part of the job. Impact measurement means measuring the changes in people's lives (outcomes) that result from a humanitarian project, striking a balance between qualitative and quantitative data. Questions that help identify what is working and what is not often go unasked during an emergency response. They are left instead to evaluators. As a result, information that could inform decision-making and save lives is sometimes discovered only after a crisis is over. One way of discovering the difference or impact a project is making is to ask the women, men, and children caught up in the emergency. For years NGOs have been promising to 'be accountable' to them: to seek their views and to put them at the heart of planning, implementing, and judging our response to their emergency. In practice, that is a promise that has proved hard to keep. A combination of factors - including lack of know-how, time, or staff, and the situation itself - too often make impact measurement and accountability no-go areas during emergency response.