* Classroom Hours: Most colleges assign credit hours based on the number of hours per week a student is expected to spend in class *and* outside of class (studying, homework, projects). A 1-credit course might involve only 1 hour of class per week, plus a commensurate amount of outside work. A 3-credit course would be more like 3 hours of class, plus additional hours of outside work.
* Laboratory Hours: Science courses often have a lab component. Lab hours can contribute to the total credit hours for a course.
* Independent Study: Some courses, particularly at the upper-level undergraduate or graduate levels, might be structured as independent study. The credit hours reflect the expected workload even though there might not be formal classroom meetings.
* Credit by Exam: Some colleges allow students to earn credit by demonstrating proficiency through exams, such as CLEP, DSST, or AP exams. Passing these exams can grant you college credit without taking the corresponding course.
* Experiential Learning: Colleges sometimes grant credit for relevant work experience, internships, or other forms of experiential learning. These credits are usually awarded based on a formal evaluation of the experience.
In short, there's no single answer to "how do you get one credit." It depends entirely on the specific course and the college's policies. You'll need to look at the course catalog or syllabus of the specific course you're interested in to understand how many hours of class and out-of-class work will be required to earn that one credit.