Astronomers need specific skills for the job. Because the field blends physics and chemistry, astronomers need to know how to use scientific methods, such as observation and measurement, to answer research questions. To solve problems, astronomers need thinking skills, including logic, reason and judgment. Computer skills help them analyze large data sets or make complex calculations. Also, communications skills are invaluable. Astronomers write papers, reports and lecture notes that are technical, but easy to understand for students, the public and other astronomers. Public-speaking skills enable astronomers to present findings to peers.