CS50 Syllabus

See cs50.ly for what’s new and why. See cs50.ly/faqs for FAQs.
Email heads@cs50.harvard.edu with questions.

You are expected to

https://cs50.harvard.edu/

You may take this course Satisfactory/Unsatisfactory (SAT/UNS) or for a letter grade. Even though first years may not ordinarily enroll in both a Freshman Seminar and another non-letter-graded course in any one term, they may take both CS50 and a Freshman Seminar SAT/UNS. When taken for a letter grade, CS50 meets the General Education requirement for undergraduates for Empirical and Mathematical Reasoning.

Whether taking the course SAT/UNS or for a letter grade, you must ordinarily submit all nine problem sets, take one test and one quiz, and submit a final project in order to be eligible for a satisfactory grade unless granted an exception in writing by the course’s heads.

Final grades are determined using the following weights:

Problem sets and the final project are evaluated primarily along axes of scope, correctness, design, and style, with scores ordinarily determined by scope × (3 × correctness + 2 × design + 1 × style). Scores are normalized across teaching fellows at term’s end, so mid-semester comparisons among students of scores are not reliable indicators of standing.

Although you must submit all nine problem sets, your lowest score among those problem sets on which you received perfect scores for the axis of scope will be dropped when final grades are determined.

Know that CS50 draws quite the spectrum of students, including "those less comfortable," "those more comfortable," and those somewhere in between. However, what ultimately matters in this course is not so much where you end up relative to your classmates but where you, in Week 11, end up relative to yourself in Week 0.

Each student’s final grade is individually determined at term’s end. Remarkable effort and upward trending are considered, as is input from the teaching fellows. The course does not have pre-determined cutoffs for final grades. The course is not graded on a curve. Those less comfortable and somewhere in between are not at a disadvantage vis-à-vis those more comfortable.

Ordinarily, you may not enroll in courses that meet at the same time or overlapping times. However, you may enroll in CS50 and another course whose meetings overlap fully or partially with CS50. To do so, enroll in the other course via my.harvard.edu, and then email enrollment@fas.harvard.edu to have CS50 manually added to your Crimson Cart as well. You do not need anyone’s permission or signature, and you do not need to petition the Administrative Board.

No books are required or recommended for this course. However, you might find the below books of interest. Realize that free, if not superior, resources can be found on the course’s website.

C Programming Absolute Beginner’s Guide, Third Edition
Greg Perry, Dean Miller
Pearson Education, 2014
ISBN 0-789-75198-4

Hacker’s Delight, Second Edition
Henry S. Warren Jr.
Pearson Education, 2013
ISBN 0-321-84268-5

How Computers Work, Tenth Edition
Ron White
Que Publishing, 2014
ISBN 0-7897-4984-X

Programming in C, Fourth Edition
Stephen G. Kochan
Pearson Education, 2015
ISBN 0-321-77641-0

CS50 officially meets on Mondays and Wednesdays, from 1pm until 2:30pm in Sanders Theatre, but you are only expected to attend in person the course’s first lecture on Wed 8/31 and last lecture on Mon 11/21. If you’ve a conflict, though, you’re welcome to watch those lectures online.

Other lectures are filmed in Sanders a few days in advance, with videos thereof released on Fridays so that you have access to problem sets' material earlier than in past years; you are welcome but not expected to attend those filmings. On Wednesdays, CS50 holds "walkthroughs" in Sanders for students who would like additional guidance on problem sets; you are welcome but not expected to attend those walkthroughs.

A schedule of lectures, subject to change, appears below.

Lectures are supplemented by weekly, 90-minute sections led by the teaching fellows. Different sections are offered for those less comfortable, those more comfortable, and those somewhere in between. You will be asked for your sectioning preferences on Problem Set 0, and you will be assigned to a section (and teaching fellow) shortly thereafter.

A schedule of sections, subject to change, appears below.

* Course-wide and filmed.

Office hours are opportunities for help with problem sets alongside the course’s teaching fellows and course assistants.

Office hours begin on Wed 9/7. A schedule of office hours will appear on the course’s website.

Integrated into problem sets are "walkthroughs," videos that offer direction on where to begin and how to approach problems. At 1pm on most Wednesdays in Sanders Theatre, the course also offers walkthroughs for students who would like additional guidance on problem sets; you are welcome but not expected to attend.

Available after problem sets' deadlines are "postmortems," videos via which the course’s staff explore actual solutions to problem sets. You are encouraged to watch postmortems for insights into how else you could have (or should have!) implemented your own solutions.

For students who avail themselves of the course’s other resources but still find themselves struggling, the course offers tutoring, to the extent possible, providing opportunities for students to work with the course’s staff one-on-one or in particularly small groups. To arrange, contact the course’s heads.

Nine problem sets are assigned during the semester. Each is due by noon on a Monday. Late work is not ordinarily accepted, except in cases of emergency. Although you must submit all nine problem sets, your lowest score among those problem sets on which you received a perfect score for the axis of scope will be dropped when final grades are determined.

A schedule of problem sets, subject to change, appears below.

Due by noon on Mon 10/17 is a take-home test that will cover Weeks 0 through 5 (and Problem Sets 0 through 5). The test is open-book: you may use any and all non-human resources during the test, but the only humans to whom you may turn for help or from whom you may receive help are the course’s heads.

Due by noon on Thu 11/17 is a take-home quiz that will cover Weeks 0 through 10 (and Problem Sets 0 through 8), with emphasis on Week 6 (and Problem Set 6) onward. The quiz is open-book: you may use any and all non-human resources during the quiz, but the only humans to whom you may turn for help or from whom you may receive help are the course’s heads.

The climax of this course is its final project. The final project is your opportunity to take your newfound savvy with programming out for a spin and develop your very own piece of software. So long as your project draws upon this course’s lessons, the nature of your project is entirely up to you, albeit subject to the staff’s approval. You may implement your project in any language(s) as long as the staff approves. You are welcome to utilize any infrastructure, provided the staff ultimately has access to any hardware and software that your project requires. All that we ask is that you build something of interest to you, that you solve an actual problem, that you impact campus, or that you change the world. Strive to create something that outlives this course.

Inasmuch as software development is rarely a one-person effort, you are allowed an opportunity to collaborate with one or two classmates for this final project. Needless to say, it is expected that every student in any such group contribute equally to the design and implementation of that group’s project. Moreover, it is expected that the scope of a two- or three-person group’s project be, respectively, twice or thrice that of a typical one-person project. A one-person project, mind you, should entail more time and effort than is required by each of the course’s problem sets. Although no more than three students may design and implement a given project, you are welcome to solicit advice from others, so long as you respect the course’s policy on academic honesty.

Extensions on the final project are not ordinarily granted, except in cases of emergency. Lateness of submissions is determined down to the minute by submissions' timestamps. Submitting more than seven minutes late is equivalent to not submitting at all.

From 7pm on Thu 12/1 until 7am on Fri 12/2 is the CS50 Hackathon, an epic all-nighter during which you can dive into your final project’s implementation alongside classmates (from Harvard and Yale alike!) and staff. If you choose to partake, you’ll be asked to propose three milestones for yourself that evening: a "good" one that you intend to achieve no matter what; a "better" one that you think you can achieve; and a "best" one that you hope to achieve.

Dinner will be served around 9pm, second dinner will be served around 1am, and those still standing around 5am will be treated to breakfast at IHOP.

From 11am until 4:30pm on Fri 12/9 is the CS50 Fair, an epic display of final projects. Not only is the CS50 Fair a venue at which to see classmates' projects and demo your own, it is an opportunity to mingle with students, faculty, and staff from across campus as well as recruiters from industry. Attendance is expected of all students.

Also in attendance are popcorn, candy, and a raffle with (fabulous) prizes. Family and friends are welcome to join.

This course’s philosophy on academic honesty is best stated as "be reasonable." The course recognizes that interactions with classmates and others can facilitate mastery of the course’s material. However, there remains a line between enlisting the help of another and submitting the work of another. This policy characterizes both sides of that line.

The essence of all work that you submit to this course must be your own. Collaboration on problem sets is not permitted except to the extent that you may ask classmates and others for help so long as that help does not reduce to another doing your work for you. Generally speaking, when asking for help, you may show your code to others, but you may not view theirs, so long as you and they respect this policy’s other constraints. Collaboration on the course’s test and quiz is not permitted at all. Collaboration on the course’s final project is permitted to the extent prescribed by its specification.

Below are rules of thumb that (inexhaustively) characterize acts that the course considers reasonable and not reasonable. If in doubt as to whether some act is reasonable, do not commit it until you solicit and receive approval in writing from the course’s heads. Acts considered not reasonable by the course are handled harshly. If the course refers some matter for disciplinary action and the outcome is punitive, the course reserves the right to impose local sanctions on top of that outcome that may include an unsatisfactory or failing grade for work submitted or for the course itself. The course ordinarily recommends exclusion (i.e., required withdrawal) from the course itself.

If you commit some act that is not reasonable but bring it to the attention of the course’s heads within 72 hours, the course may impose local sanctions that may include an unsatisfactory or failing grade for work submitted, but the course will not refer the matter for further disciplinary action except in cases of repeated acts.

Harvard plans to record audio, photos, and video of Computer Science 50 (CS50) lectures, sections, office hours, seminars, and other events and activities related to CS50 (the "Recordings"), with the aims of making the content of the course more widely available and contributing to public understanding of innovative learning (the "Projects"). The Recordings, or edited versions of them, may be made available to other Harvard students, to students at other educational institutions, and to the broader public via edX, the Internet, television, theatrical distribution, digital media, or other means. It is also possible that the Recordings may be used to make other derivative works in the future. Students may elect not to appear in photos and video used in the Projects and may still participate fully in CS50.

When you submit Problem Set 0, you will need to sign online an Acknowledgement and Authorization in the following form:

Unless you opt out as described in the Acknowledgment and Authorization, you are agreeing, by attending CS50, that your participation in CS50 and related activities may be recorded and used by Harvard in connection with the Projects without further obligation or liability to you, even if you do not sign any authorization.

If you have any questions about the above, contact recordings@cs50.harvard.edu.