This webpage was copied and modified from previous
This policy statement is unfortunately necessary, thanks to the
actions of a tiny minority of students. If you have any
questions or concerns, please don't hesitate to ask in lecture,
in lab, during office hours, on Piazza, or by email.
Be honest. Cite your sources. We mean it. If you need help,
please ask. Don't be stupid!
Each student (or homework group) must write
their own solutions, in their own words, and must properly
credit all sources.
These are the same ethical standards that researchers are expected
to follow in their
formal publications. For comparison, see the guidelines
published by the
Association for Computing Machinery (ACM),
the American Mathematical Society (AMS), the
American Physical Society (APS), the
Institute of Electrical and Electronics Engineers (IEEE), and the
Society for Industrial and Applied Mathematics (SIAM).
For more information and examples, see any of the following:
If you have any doubts about whether something constitutes
plagiarism, talk to Jeff or the TAs, and err on the side of
Cite Your Sources
We strongly encourage you to use any printed, online, or living resource at your disposal to help you solve homework problems, but you must cite your sources.
There are only two exceptions to this rule. You are not
required to cite the following:
- If you use an idea from a book, cite the book.
- If you use an idea from a paper, cite the paper.
- If you use an idea from Wikipedia, cite Wikipedia.
- If you use an idea from CS StackExchange, cite CS StackExchange.
- If you use an idea from last semester's homework solutions, cite last semester's homework solutions.
- If you use an idea from another student, cite that student.
- If you use an idea from the bathroom grafitti at Kam's, cite the bathroom grafitti at Kam's.
- If you use an idea from your mom, cite your mom.
Submitting someone else's work without giving them proper credit
is plagiarism, even if you have the other person's explicit
Citing your sources will not lower your homework grade.
Allowing someone else to use your ideas without giving you credit
is also an academic integrity violation.
Official course materials (lectures, lecture notes, homework
and exam solutions from this semester)
Sources for prerequisite material (which we assume you already
know by heart)
Use Your Own Words
Verbatim duplication of any source,
even with proper citation, is plagiarism. In particular:
Classes in some other departments allow and even encourage
verbatim copying in small doses. For example, if you want to
claim that an expert holds an important or controversial
opinion, it is usually better (more honest, more accurate) to
quote them verbatim, instead of rewriting their opinion in your
- Copying verbatim from the lecture notes is plagiarism.
- Copying verbatim from a textbook solution manual is plagiarism.
- Copying verbatim from old CS 374 or 473 homework or exam
solutions is plagiarism.
- Submitting work done entirely by another student is
plagiarism, even if that student is part of your
- Allowing another student to copy your work verbatim is also
an academic integrity violation, even if that student is
part of your homework group.
But computer science classes are different. We won't ask you to
defend a hypothesis or opinion using evidence or rhetoric. What
we will ask for are formal, logical, mathematical arguments.
Expert opinion is irrelevant here; the math must speak for itself.
In particular, we are asking you to demonstrate your expertise
in formal, logical, mathematical reasoning. You can only
demonstrate expertise in something by actually doing it. (The
same argument goes for programming classes. Your MPs are not just
asking you for working code; they are asking you for
evidence of your ability to independently produce
That said, if you want to use an algorithm from Jeff's notes in
your solution, just use it (and cite it) and carefully describe
any necessary changes.
Immortality. I notice that as soon as writers broach
this question they begin to quote. I hate quotation. Tell me
what you know.
— Ralph Waldo Emerson, Journals (May 1849)
Students frequently overuse direct quotation in taking
notes, and as a result they overuse quotations in the
final paper. Probably only about 10% of your final
manuscript should appear as directly quoted
matter. Therefore, you should strive to limit the amount
of exact transcribing of source materials while taking
— James D. Lester, Writing Research Papers (1976)
Don't Be Stupid
There are several more serious ways to violate the university's
academic integrity policies, such as collaborating with or copying
from another student during an exam, hiring an impostor to write
homework solutions or take exams for you, changing the answers on
a graded homework or exam before asking for a regrade, falsely
claiming to have submitted a homework or taken an exam, and
modifying or destroying other students' graded work. But you
already know not to do anything that stupid!
These penalties are consistent with
the CS department's recommendations.
In accordance with department,
policy, we report all academic integrity cases to the
Computer Science department, to the student's college, and to the
Senate Committee on Student Discipline. We also report offenses
by computer science graduate students to their advisors. Multiple
offenses, even in different classes, can result in suspension or
Our high expectations for graduate students extend to issues of
academic integrity. A notice of any cheating offense by a
graduate student will be entered into their file, where it will be
seen by the student's advisor, as well as their qual, prelim, and
thesis committees. Many professors refuse to advise MS or PhD
students who have committed even a single cheating offense; the
risk to our professional careers if a student acts unethically
in research is simply too high.
If you cheat, you may be signing your own academic death warrant.
Regardless of whether it constitutes plagiarism, or whether you
get caught, getting too much help on your homework will hurt your
final grade. If you don't learn how to solve algorithmic problems
on your own,
you will perform poorly on the (closed-book, closed-notes)
exams, which make up 70% of your final course grade. Several
students with ≥90% homework averages have failed this course.
The default penalty for cheating on a homework problem is a
grade of zero on the entire homework set, which we
will not drop when we compute your final course
grade. (In practice, the effect of this penalty is about half
of a letter grade.)
- The default penalty for cheating on an exam is a grade of
zero on the entire exam, which we will not
drop when we compute your final course grade. (In practice,
the effect of this penalty is roughly two full letter grades.)
The penalty for a second offense of any kind, or a
particularly egregious first offense, is an F in the course.
Groups of up to three people are allowed
to submit a single solution for each homework. Every member of
the group receives the same grade and the same credit for the
entire assignment. That means every member of the group is
responsible for the entire assignment.
Group solutions must represent an honest
collaborative effort by all members of the group. In
particular, groups must not delegate one problem to
each group member; only the students who actively worked on a
problem may add their names to the solution.
At a minimum, you must read, understand, and approve anything
submitted with your name on it. Allowing someone else to add
your name to a solution to which you made no contribution is
This does not mean that every student in a group must contribute
good ideas or must help in the actual writing of
every group solution. Asking "stupid" questions, proposing bad
ideas, shooting down bad ideas, working out examples (even if they
don't appear in the solution), uncovering bugs, and even just
acting as a sounding board for other group members are all
If a submitted homework contains plagiarized material, we will
separately determine each student's culpability (if any) and
penalty (if any), in accordance with
Code. By default, every member of the homework group will
be given the same penalty. (Again, this is the same standard
that is applied to coauthors of research papers.) If you cheat,
you are not only endangering your grade, and possibly your
academic career, but your colleagues’ as well.
As illustrations, consider the following scenarios. All scenarios
involve a group of three students (A, B, and C) collaborating on a
three-problem homework set, who argee in advance that each student
will write up and submit the solution for one problem — A will
handle problem 1, B will handle problem 2, and C will handle
problem 3 — with all three names at the top. Variants of all
these scenarios have actually happened. Yes, even the last two.
Each student writes up a complete solution for their
problem, in their own words and properly citing of all
sources, but with no involvement from the other group members.
The students then email their solutions to each other; after
some discussion, everyone agrees to submit all three solutions
exactly as written. Each student submits the solution they
wrote, with all three names at the top.
All three group members first discuss and jointly work out
sketches of solutions for all three problems. Then each
student writes a detailed solution to their individual
problem, in their own words and properly citing all sources.
With no further discussion, each student submits the solution
they wrote, with all three names at the top.
Each student writes up a complete solution for their
problem, in their own words and properly citing of all
sources, but with no involvement from the other group
members. With no further discussion, each student submits
the solution they wrote, with all three names at the top.
All three students are guilty of plagiarism and would
receive an undroppable zero on the entire homework set.
- All three group members first discuss and jointly work
out sketches of solutions for all three problems. Student A
later finds a solution to problem 1 on the web and submits it
without proper citation, with all three names, with no further
discussion with B and C. Students B and C independently write
up solutions to their problems, properly citing all sources,
and submit them with all three names, with no further
Student A is guilty of plagiarism and would receive an
undroppable zero on the entire homework set. Students B and
C followed the rules; their problem 1 would be
Student B finds a solution to problem 2 on the web and
submits it verbatim with all three names at the top of the
first page, as the group agreed. A and C had no knowledge
of student B's plagiarism, and no other involvement in
solving problem 2. Students A and C collaborate on
problems 1 and 3, with no involvement from student B, and
submit a properly written solution with all three names,
as they had agreed.
All three students are guilty of plagiarism, although for
different reasons. All three students would receive an
undroppable zero on the entire homework set.
The solution for problem 3 is a verbatim copy of another
source. Immediately after submitting the homework, but
before the plagiarism is discovered, all three students drop
the course. None of the students responds to the initial
charge of plagiarism or to repeated emails from the
instructor asking to discuss the situation.
All three students are guilty of plagiarism. An academic
integrity infraction is added to their permanent records
even though they dropped the course.
All three group members discuss and jointly work out
sketches of solutions for all three problems. Student A
later finds a solution to problem 3 on the web and emails
the text (copied verbatim) to student C, with a clear
citation to the original source. Student C copies the
text of student A's email verbatim into his solution,
without consulting or citing the original source, under
the mistaken belief that the text is student A's own work.
All three students submit their respective solutions with
all three names at the top, with no other involvement by
the other group members.
Student C is technically guilty of plagiarism, but they
would probably receive only a warning. Problem 3 would
be forgiven for
all three students.
Each student writes up a complete solution for their
problem, with no involvement from the other group members.
A and C write their solutions in their own words, properly
citing all sources, but B copies their solution verbatim
from another source. B and C email their solutions to the
entire group. A does not respond to B and C's email or send
their own solution. After some discussion (without A),
B and C agree to submit their solutions exactly as
written, with only B and C named on the first page. B never
reveals that their solution to problem 2 was plagiarized. A
also submits their solution to problem 1, with all three
names on the first page, without B and C's knowledge or
Let's go through this one carefully.
- Student A is technically guilty of facilitating
plagiarism, but would probably receive only a warning,
along with (droppable) zeros on problems 2 and 3.
- Student B is guilty of plagiarism and would receive
an undroppable zero on the entire homework set.
- Student C followed the rules. They would receive a
(droppable) zero on problem 1; their problem 2 would be
they would be strongly encouraged to find new
- The instructor has a headache.
Almost every instance of plagiarism I have seen was motivated by a
combination of two factors.
Desperation: The student
feels overwhelming pressure to improve
their performance, despite gaps in
their understanding. The student
might be overwhelmed by work in other
classes, or financial pressure to
graduate, or parental/cultural
expectations. This might be the
hardest course the student has ever
taken, and their merely good performance is a blow to
their aspirations or self-image. The student may be
the feeling that they really aren't good enough to be here
(despite evidence to the contrary), and that their fraud
will be uncovered if they admit that they can't do
something. The student might have trouble with English, and
therefore worries that rewriting someone else's text would
distort the meaning. Perhaps the student is dealing with
depression, serious illness, divorce, or a death in the
family. Or maybe the student simply sees no way to satisfy
the instructor's unreasonable or unclear expectations
If you find yourself in this situation,
ask for help! If you need help understanding the
material, come to office hours, ask questions in class, ask
questions on the newsgroup, talk to your fellow students.
The instructional staff will even make extra appointments to
help guide you through the material or give you feedback on
tentative solutions, but only if you ask. (But
please remember that our goal is to help you master the
material, not just to help you get a better grade.)
If you think a homework problem is unclear, please ask
for clarification. Your confusion might indicate a gap in
your understanding of the course material, but it might also
indicate that the question is poorly stated, unfairly hard,
or even impossible.
Our job is to help you learn the material;
please let us know if we aren't doing our job.
We do expect solutions to be written in clear, coherent
English. If you are thinking of copying someone else's
words because you are uncomfortable with English, you are
probably better off taking a class to improve your English
instead of this course.
Asking for help does not make you "look stupid". Quite the
opposite—it means you are smart enough to recognize your own
limitations and work to overcome them. Asking for
clarification is not an insult to the instructor or the TAs.
Quite the opposite—questions are valuable feedback that we
can use to teach more effectively. Everyone suffers
from Impostor Syndrome occasionally,
including your professors.
Most importantly, please remember that your grade is not a
statement about your intelligence, your potential for
success, or your worth as a human being; it's only feedback
about your mastery of the course material.
If your situation is very serious, or not directly
related to this class, you may prefer to discuss your
situation with your department or college advisor, a family
member, a trusted friend, or
counseling center, but please talk to someone.
Different expectations: The student is used to an
academic culture where plagiarism is tolerated or even
encouraged. Maybe they come from a high school with
litigious parents who discourage teachers from punishing
cheaters. Maybe they come from a country where students
are expected to parrot back their instructors'
exact words to demonstrate understanding. Maybe cheating
was inconsistently or ineffectively enforced in their past
classes; they've seen cheating students succeed (getting
higher grades, or even better jobs) where honest students
Please be aware that our standards for academic
integrity may be different than what you're used to. This
point is especially important for international
students. The standards we apply in this class are a
proper subset of the standards applied to
and most other
professional scientific researchers. (Fortunately,
we don't have to worry about
and author ordering policies,
accurate recording and reporting of experimental results,
or ethical issues with
human or animal test subjects.)
Our job as instructors is to help you master the course
material. We ask that you write everything yourself so
that we can make an honest assessment
of your facility with the course material, and
therefore give you useful
feedback. We allow wide latitude in choosing the
resources you need to learn, because we believe that
freedom will help you learn more effectively. We trust
that you will use those resources responsibly and
ethically. Plagiarizing other people's work to improve
your grade is an abuse of that trust. It is unfair to us
and to your fellow students.
We are painfully aware of differences in cheating policies
and their enforcement in different classes, both within
and outside the computer science department. Within the
guidelines of the
Code, the university gives faculty broad discretion
(under the rubric of academic freedom) in defining what
constitutes "cheating" and how stringently cheating
policies are enforced. Sometimes these differences lead
students to believe that cheating policies are overly
restrictive or inconsistent, and so can be justifiably
We believe that our policies are fair, but even with the
best of intentions, people make mistakes. If
you believe that any policies in this course are unclear,
unfair, or inconsistently applied, we strongly encourage
you to voice your concerns
to the instructor,
any of the teaching asisstants, and/or
the department administration.
If you wish to complain anonymously, feel free to
send me an anonymous private message on Piazza, or leave a
note in my mailbox, with my assistant Elaine Wilson, or
under my office door.
Apathy: Very rarely, students cheat simply because
they want a good grade (or a degree) at all costs, with no
thought whatsoever for learning or fairness. We have
absolutely no sympathy for these students. You have every
right to rob yourself of the educational opportunity you
(or your advisor, or your parents) have paid for, but
don't expect us to help you.
Last modified: Wed 2019-01-16 17:23:51 UTC 2019 by Sariel Har-Peled