The goal of data collection is wisdom. In the estimation world wisdom means knowing when it’s safe to bet your shirt on this new project you want to initiate. If you keep that perspective in mind it becomes much easier to identify what information you need to make wise decisions and what data you have to have to generate the necessary information. Every data item you collect costs time and money, transforming that data into information cost more time and money. So be frugal, figure out what you need to know to make you choices the correct ones and you will be that much closer to being happy and wise.