COS126

• Syllabus
• Meetings
• Lectures
• Precepts
• Assignments
• Exams
• Help!

Caution! You are looking at an out-of-date version of this website from Fall 2015.
To access the current version, click here.

Syllabus

Description. This course is an introduction to computer science in the context of scientific, engineering, and commercial applications. The goal of the course is to teach basic principles and practical issues, while at the same time preparing students to use computers effectively for applications in computer science, physics, biology, chemistry, engineering, and other disciplines. Topics include: programming in Java; hardware and software systems; algorithms and data structures; fundamental principles of computation; and scientific computing, including simulation, optimization, and data analysis.

Prerequisites. None.

Class Meetings. Class meets Tues/Thurs 10:00-10:50am. For more info, see the Meetings page.

Lectures. Lectures are pre-recorded and available online.

Precepts. Precepts meet twice a week, on either Tuesdays & Thursdays or Wednesdays & Fridays.

	Required reading. R. Sedgewick and K. Wayne, Introduction to Programming in Java: An Interdisciplinary Approach, Addison-Wesley, 2007. ISBN 0-321-49805-4. We will be referencing this text all semester. The lectures are based on its contents. (Labyrinth)
	Suggested reading.D. Harel, Computers Ltd.: What They Really Can't Do, Oxford, 2003. ISBN 0-19-860442-4. This is an introduction to theory that will be useful in the second half of the semester. (Labyrinth)

Staff

COS 126 is taught by a mix of research faculty, teaching faculty, and graduate students. Below you will find our contact information, but please keep in mind that it is almost always more appropriate to post your question on Piazza rather than emailing an individual staff member. Our office hours and precept schedule can be found on the "Help!" page.

Enrollment problems? Please contact Colleen Kenny-McGinley and Dan Leyzberg.

Bob Sedgewick Faculty Instructor	Dan Leyzberg Faculty Co-Lead Preceptor	Jérémie Lumbroso Faculty Co-Lead Preceptor	Alan Kaplan Faculty Co-Lead Preceptor	Donna Gabai Faculty Preceptor
Douglas Clark Faculty Preceptor	Andrea LaPaugh Faculty Preceptor	Stephen Cook Graduate Student Preceptor	Ted Brundage Graduate Student Preceptor	Ranjana Addanki Graduate Student Preceptor
Yuan Cao Graduate Student Preceptor	Aohui "Lawrence" Lin Graduate Student Preceptor	Kevin Boutarel Graduate Student Preceptor	Tong Zhang Graduate Student Preceptor	Ming-Yee Tsang Graduate Student Preceptor
Bingqing Li Graduate Student Preceptor	Daniel Munro Graduate Student Preceptor (ISC only)	Bianca Dumitrascu Graduate Student Preceptor (ISC only)

Precepts

Resources

This site. The website you're currently reading contains a wealth of documents and online tools for you to practice and study computer science, including the course lecture slides, online programming activities (with solutions), a Java code visualizer, and an archive of the past ten semesters' worth of exams in this course, also with solutions. A quick way to get back to this page is to type: princeton.edu/~cos126.

Booksite. As a reference to the required textbook for this course, we provide a companion website that has extra exercises and plenty of reference material so you won't have to dig though the textbook for syntax. That said, it is not a replacement for the physical book. The book is the only place to find a detailed explanations of the course curriculum. You will be responsible for a carefully reading of its contents on written exams.

Piazza. Piazza is an online forum where you can ask questions anonymously and get an answer from the COS 126 staff rather quickly. You can also read your fellow students' anonymous questions and the staff responses. We recommend reading Piazza a couple times per week to ensure that you are keeping up with your peers.

Blackboard. We use Blackboard in this course to distribute course announcements and grades.

Course software.This course has an associated software package called introcs that enables students to write and test code. Install it on your computer by following the instructions for your operating system: either Windows, Mac, or Linux.

Novice precepts. As of Spring 2015, COS 126 is offering two kinds of precepts: those intended for absolute beginners ("novice precepts") and those intended for beginners with some degree of comfort with computational/logical thinking ("regular precepts"). This entire course is designed to be approachable for students with no computing background, but we have found that absolute beginners prefer to have more time to cover the same topics and exercises in precept, so you may choose to register for either 80 minute or 50 minute precepts. If you want to switch from a regular precept to a novice precept, or vice versa, please contact the lead preceptors.

Cluster computers.For students who may not have a computer or for students whose computers fail during the semester, we provide cluster machines in Friend Center 017. Click here for information on using the labs.

GRADING

Grade weighting. Semester grades in COS 126 are composed of two two-part exams, worth a combined 50% of the grade, nine weekly programming assignments worth 40%, one final programming project worth the remaining 10, and staff discretion.

Curve. We typically do not curve grades in this class. You should expect that the cutoff for an "A" will be approximately 93% of the available points, for an "A-" you'll need approximately 90% and so on.

Midterm exams. There are two two-part exams during the semester. One set will be given in middle of the semester, and one set in the last week or so of classes. The exams have a written portion, worth 70% of the exam grade, and a programming portion, worth the remaining 30. There will be no final exam. No makeup exams will be considered without a Dean's recommendation and our preapproval.

Programming assignments. There are nine weekly programming assignments all equally weighted.

Final project. The final project is a large programming assignment, approximately the length of two weekly assignments. It is due at the end of Reading Period.

Late submissions. The weekly assignments in this course are due on Monday nights at 11:59pm. Submissions made at 12:00am will be marked late. If any part of an assignment is submitted late, the entire assignment will be marked late. Students have four free late days to use as they wish throughout the semester. To use a late day, students must check the checkbox on our online submission system, Dropbox, that indicates that their work is not complete. If the deadline has passed and the checkbox is not checked, submitted work will be graded as-is. Students who submit late work after they have used all four free late days will lose 20% of the possible points on the late assignment per day or partial day late thereafter. Outside of this policy, the only late work that will be excused is in the case of medical or personal emergency as indicated by a letter from a Dean, Director of Studies, or from McCosh Health Center. We will not accept any work for this semester after Dean's Date. You cannot use any late days on the final project.

Extra credit. Some of the assignments in this course feature optional extra credit sections intended for students who have completed every other part of the assignment first. In COS 126, extra credit points are only given a small discretionary value at the end of the term. Rather than adding the extra credit points to the total number of earned points in the semester, the course staff considers extra credit for students who end the semester close to a grade boundary, potentially pushing an "A-" to an "A" for example. Note that extra credit sections have stricter collaboration and late policies than the rest of the assignment: Extra credit may not be submitted late under any circumstances. Extra credit may not be discussed, even conceptually, with anyone except your partner and the course staff. Course staff are only permitted to clarify the wording of the extra credit, as we would on an exam question. Staff should not give hints or tips on extra credit nor help debug a student's extra credit code. Students working on a partnered assignment may choose to do the extra credit individually or together. You should decide this before you begin the extra credit.

Regrades. If you feel we have made a mistake while grading your work, please write a short note describing the potential mistake and attach it to the graded work. Return it to your preceptor within two weeks of the work being handed back.

Auditing COS 126. Auditors must identify themselves to the lead preceptors via email as soon as possible. Auditors will receive only automated feedback on work (i.e., immediate feedback in the submission system, as well as an e-mailed copy of the testing performed on their submissions). To earn audit credit, you must successfully complete all of the programming assignments and the final project (i.e., pass all Dropbox test cases), using at most four late days. Auditors do not take the exams in this course.

Collaboration

Ask for help. COS 126 is a challenging course that requires a significant time commitment for most students. If you fall behind, please (please!) ask for help! The course staff will be happy to go through the material with you and help you work on your assignments or study for our exams. There is no excuse for plagiarism.

Monitoring submissions. We actively police every submission made to us for every assignment and exam. We have archives of every imaginable source of solutions to our assignments including many years of Princeton students' past submissions. We compare these results both by automated systems that check for similarities in code structure and by hand. We take no pleasure in bringing cases to the Committee on Discipline, but we will continue to do so as necessary. It's our job to keep the playing field level for the vast majority of students who work very hard in this course. For an account of a recent cluster of plagiarism cases in COS 126, see this article in The Daily Prince.

Ground rules. In this course you may only receive help from people in the ways described below. You must acknowledge all the help you receive in the readme.txt file you submit for each assignment. You are not allowed to post questions about the course or about any of our assignments on any website other than our Piazza page. If you have any question whatsoever about what is allowed, please ask us!

Your work. When we talk about work, this includes code, comments, readme files, or anything else you create for this course.

• You must individually compose all of your own work during the term.
• Your work must never be shown or communicated to anyone who is taking COS 126 now or who might take COS 126 in the future.
• Abetting plagiarism is a serious offense. Offenders will be reported to the Committee on Discipline for investigation.
• You must never place your work in any public location (including websites, leaving printouts in a classroom, etc.). Password-protect your laptop if left unattended.
• You must never give a copy of your work to anyone, except for course staff.

The rules above apply both to finished and unfinished work. They continue to apply even after this semester is over.

In some assignments, you are given some code to begin with. Like other course materials, you are allowed to read and discuss the original code with other students, to figure out what it does and how it works. But once you make a change to the code, it becomes your work and the rules above apply to it.

Citing allowable references. Copying or adapting work that is not yours is only permitted if it comes from the course materials. If you do so, you must cite what you used.

• A sample citation:

      /* The formula below comes from "Luminance.java" on the booksite,
         http://introcs.cs.princeton.edu/java/31datatype/Luminance.java.html */
            return .299*r + .587*g + .114*b;
      

• It's optional to cite anything that the assignment or checklist tells you to copy.

Reading someone else's solutions (or partial solutions) for assignments (or anything similar to any COS 126 assignment) is not allowed.

Peer Discussion

You must individually compose your solutions for the course, but some common concerns may be discussed with other current students, or publicly on Piazza. Because of the rules above, these discussions must be kept at a general level, without sharing code or other work about assignments. For example, you may ask about:

• How to interpret an error message. E.g., "What does StackOverflowError mean?"
• Using the DrJava GUI or command-line interface. E.g., "How do you copy text from the Terminal/Command Prompt?"
• The definition of a piece of Java syntax. E.g., "What are the parts of a for loop?"
• Clarifying wording in lecture slides, readings, or the requirements specified by an assignment.
• Book/booksite/precept exercises or old exam questions.

Don't let someone be too helpful: it is not allowed for someone to lead you step-by-step through any part of an assignment.

Help From COS 126 Graduates

Anyone who successfully completed COS 126 in a previous term is allowed to assist you in the following ways, similar to what a lab TA would do:

• They may look at your code.
• They must not do any writing or typing (in short, "hands in pockets").
• They may help debug, but they must not give directions on what steps are necessary to complete the assignment.
• They should give thought-provoking suggestions rather than dictating what to change.
• While helping you, they must not look at any other solutions, including their own old ones.
• They can't give high-quality help if they need to rely on a reference. Please seek course staff, office hours, lab TAs or Piazza instead.
• They cannot help with extra credit at all.

Pair Programming

On certain assignments the collaboration policy is relaxed to allow working with a partner.

• Work with a partner whose skill level is close to your own.
• You must use pair programming: one partner types (the driver) and the other reviews the work, identifies bugs, and asks questions (the navigator). Swap roles each 30 to 40 minutes. Take breaks from coding to brainstorm and discuss high-level ideas.
• See: All I Really Need to Know About Pair Programming I Learned in Kindergarten (Laurie Williams and Robert Kessler)
• All work for that assignment must be done with both of you together, sharing the same computer screen. This includes debugging, testing, commenting, writing the readme, and submitting the files online.
• Come to office hours or the lab with your partner. Otherwise you cannot change your code while you visit.
• You should each keep a copy of your final submission.
• To transfer files between partners, you must use e-mail attachments or flash drives. Using file-sharing or pastebin-like webservices is specifically not allowed for security reasons.
• Do not log in to the CS dropbox from your partner's machine, and do not give your partner your CS Dropbox password.

If two students begin working on an assignment as partners and cannot complete it together, at least one student must contact the lead preceptor to request a partnership dissolution.

Taking COS 126 again.

If you took COS 126 (or part of it) before, you may look at your old work but you may not look at the feedback we gave you on your old work. What's more, you may not look at your old work on assignments where: you previously partnered; or you are partnering this time; or you were previously found responsible for plagiarism by the Committee on Discipline. In our experience, students who re-do all of the assignments from scratch are much more likely to succeed in the course, so this is what we strongly recommend.

Plagiarism

If anything about these policies is unclear during the course, please consult us and ask for clarification. Princeton's Rights, Rules, Responsibilities handbook asserts:

The only adequate defense for a student accused of an academic violation is that the work in question does not, in fact, constitute a violation. Neither the defense that the student was ignorant of the regulations concerning academic violations nor the defense that the student was under pressure at the time the violation was committed is considered an adequate defense.

We use software to compare student submissions. Pairs that are identified as similar are inspected manually by course staff.

Violators of the course policy will be referred to the Committee on Discipline for review. If found responsible, you will receive an F as a course grade plus whatever disciplinary action the Committee imposes. The typical penalty they impose for plagiarism is suspension from the University for one year.