Impact of Student Time Spent on Performance in a CS1 Class, Including Prior Experience Effect

Computer science instructors have long advised students that success in CS1 requires many hours, such as 8-10 hours/week outside class time, but students often don't believe it. Recently, the most-widely used CS1 learning system (zyBooks), which is web-native and records student activity data, began providing instructors with data on student time spent reading and answering reading questions, solving small homework problems, and coding the programming assignments, all online and auto-graded, representing nearly all a student's time outside class. In our 300+ student CS1 course at a large state university in Spring 2022, we required all work to be done in the zyBook and analyzed student time, including analysis relative to self-reported prior programming experience. Students who completed the class averaged 6.1 hours/week, with a large standard deviation of 2.3, and averaged a B+. Students averaged 6.9 hours in weeks 1-5 leading up to the midterm, peaking at 9 hours in Week 5. We found that over 90% of students who averaged 9-12 hours/week earned As or Bs, even those reporting no prior programming experience. Spending under 4 hours/week nearly guaranteed failing the midterm, and almost no students who spent fewer than 6 hours/week got an A on the midterm (unless they had prior experience). We also found that measuring actual time is important because students overreport time in surveys. With this concrete time data available to share with CS1 students, the hope is that future students may be more likely to allocate the time needed for success in CS1.