A Border Patrol Agent deciding whether an impending confrontation involves dangerous individuals, an Inspector determining if an alien should be admitted, a supervisory Special Agent deciding whether to open a case based on certain evidence -- all of these are DHS employees using their thinking skills. Every day, DHS employees use their thinking skills in countless decisions, determinations, and investigations. Thinking skills are by no means the only skills used by DHS employees, but they are the most important. They are used in applying rules, making determinations, making predictions, and in problem solving, on-the spot decision making, and complex, deliberate decision making.In spite of the importance of thinking skills, most people do not receive special training in thinking. Employees receive training in job knowledge and supervisors usually receive training in supervisory techniques. Those types of training help employees think about very specific problems. By contrast, the purpose of this module is to teach general thinking skills that can be applied to any subject or situation.In college programs, thinking skills are taught in logic courses. In addition, courses in research methods and statistics teach people how to collect and analyze data in order to draw correct conclusions. This manual draws heavily on the parts of logic and statistical reasoning that are useful to DHS employees.