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Welcome to CSC 151! The official course description for this class is:

A lab-based introduction to basic ideas of computer science, including recursion, abstraction, state, information-hiding, and the design and analysis of algorithms. Includes introductory programming in a high-level, functional language. Prerequisites: None.

In other words, you will be introduced to the basics of computation, learning how to adequately describe and decompose problems of a computational nature so that you can effectively tell a computer the steps it should take to solve the problem. We will study some beginning concepts that make this process possible, easier to undertake, and often elegant. By the end of this course, you should be able to

  • Understand some fundamentals of computer science: algorithms, data structures, and abstraction.
  • Write computer programs (including design, documentation, development, testing, and debugging) in a high-level programming language, Scheme.
  • Read and interpret computer programs written in Scheme.
  • Solve problems using the functional paradigm, including techniques of recursion, higher-order programming, and side-effect-free functions.

While those outcomes relate to the particular disciplinary content of the course, we expect that this course will also provide you with more general outcomes.

  • Practice collaboration and active thinking
  • Sharpen general thinking, problem solving, and learning skills.

Why take CSC151?

Some basic knowledge about solving problems computationally can be useful in careers involving every major and concentration offered at Grinnell. (I invite you to challenge me with one if you are skeptical.) This course will outfit you with some versatile concepts that are applicable to most other programming languages. Plus, you get to be creative in many different ways, from problem solutions to finding new approaches to data. Creativity is highly encouraged!

Important Notices

  • Experience shows that CSC 151 exercises different parts of your brain than other courses (even other math and science courses). Expect some challenges, but have confidence that you can work through them and that you’ll come out of the course with much more knowledge.
  • Like learning a foreign language, learning in this course is cumulative: New ideas often build on ideas from earlier in the course. If you feel like you’ve missed something important, please come talk to me right away.
  • Computers have no common sense or compassion. They are complex, and sometimes they do things we don’t expect. When things go wrong, don’t blame yourself. Ask your instructor, your mentor, or a tutor for help.

In addition, we are using software that has been developed at Grinnell and may still have some bugs lurking within. It is entirely possible that it may crash for no good reason. Thus, you should develop a habit of saving your work frequently (or subconsciously twitch Control-S to save, as we do).


My goal is to help you learn as much as possible in this course; please let me know what I can do meet your learning needs. If you have a disability that requires accommodations, please contact Disability Services. Disability Services will work with you to determine your needs, and will provide you with paperwork outlining the accommodations you require. Please give me this paperwork at least a week before the course activity for which you need accommodations. If this timeline is not feasible for any reason, please contact me as soon as possible and we will work together to find a solution.

Elsewhere on this site, you can find additional notes on accommodations and my commitment to making materials accessible.

Basic needs security

Any student who has difficulty affording groceries or accessing sufficient food to eat every day, or who lacks a safe and stable place to live, and believes this may affect their performance in the course, is urged to contact the Dean of Students or the CRSSJ for support. You may also notify me, if you feel comfortable doing so, and I will do my best to help you identify and arrange other resources.

Textbooks / references

There is no required textbook for this course, as the material has been written by Grinnell faculty and is posted on this very website. However, there are some useful textbooks and references you may want to bookmark or keep handy.




My goal is for everyone taking this course to be able to demonstrate familiarity, fluency, and excellence with the course concepts. I would be very happy if you all met the goals above and received “A”s. The following weighting of individual activities will provide a basis for evaluation.

penalty only
Flash cards
Best Individual Work
5% (best of average quiz or exam grade)

Some work may be graded by someone other than the instructor. However, any questions or concerns about grading should only be directed to the instructor.

The grading scale for this course will be:


You may note that a score of exactly 90% could earn either a B+ or an A-. In this unlikely scenario, I will always choose the higher of the two grades. I also reserve the right to adjust this scale during the semester. You will be notified of any changes, and the scale will not change in the final two weeks of the course. You may ask me for your current grade in the class at any point; I will happily give you my best estimate based on the current scale and graded work so far, but these estimates are not guarantees of a specific final grade.

Good-faith grade guarantee: Because I realize that computer science may require a transition in the way you think, and different students adapt to that transition at different rates, in CSC 151 I reward effort as well as outcome. Hence, students who make a “good faith” effort in this class will pass the class, with at least a C+. A good-faith effort includes missing no more than two classes, turning in every homework assignment and at least 95% of the laboratory writeups, and spending the requisite time on each examination. A good-faith effort also includes following the course policies.


Your classmates and partner(s) depend on your contributions to learn new material and complete the required work for this course. Don’t let them down! You are expected to arrive on time and participate actively in every class.

Because your participation is so important, I will not grant excused absences except in particular and exceptional circumstances. I will deduct 2% from your final grade for each absence and 1% for each time you are late to class. These deductions are doubled if you do not send me a short note on or before the day of the absence or late attendance (e.g., “I will be unable to make it to class today” or “I apologize for missing class today” or “Another instructor has asked that I meet with them immediately after their class; I expect that I’ll be about ten minutes late to yours.”) I allot each student a 4% “penalty buffer”, which allows up to two absences (with notes) or four late arrivals (with notes) with no impact on your final grade. This policy is intended to give you the flexibility to deal with or personal or other issues (including job interviews) that require you to miss class.

I realize that there are a number of reasonable and expected absences. These include athletic events, academic conferences, course trips, and religious observations. Such absences do not count as unexecused absences provided you notify me of them at least one week in advance. I would prefer you meet with me early in the semester to discuss these instances.

I understand that some disabilities may require you to miss class. Ideally, these requirements are documented in your accommodations form. But I will do my best to make adjustments and accommodations in all cases.

If you need to miss more than two class periods for an exceptional reason (e.g. to attend an academic conference, deal with a family emergency, or due to disability or long-term illness) please talk to me as soon as possible and we will make an alternate arrangement.

If your are sick, please do not come to class. I would prefer that you reset and get better. Please seek medical care as needed. Student Health and Counseling Services (SHACS) offers health and mental health services to students. I excuse illness provided you notify me the day of class, preferably in advance of class. I do not require a note from SHACS or your doctor. Note, however, if you are ill more than a few times, I may discuss the issue with student affairs and may stop excusing illness-based absences.


Because much of our work in this course involves collaboration and discussion, I will also evaluate you on your class participation. Participating in class involves:

  • being present in class (physically and mentally)
  • coming to class on time
  • coming to class prepared
  • asking questions when appropriate
  • making positive contributions to class discussion by volunteering and when called upon
  • staying on task during lab exercises, and
  • working effectively with your lab partner(s)

Students who regularly meet these criteria can expect to earn an A- for their participation grade. I will reward students who regularly provide significant insights or guide discussion in productive ways with a higher participation score. Students who fail to participate regularly (e.g., demonstrating a lack of preparation or involvement during lab exercises) or who participate in counterproductive ways (e.g., by dominating the conversation, making inappropriate comments, or getting off-task) can expect to earn a lower score.

Weekly flash cards

As I note elsewhere, there is good evidence that making and using flash cards helps you learn the material. Flashcards are likely to be especially useful as you are mastering a new syntax and a new vocabulary.

This semester, we are experimenting with requiring each student to create flash cards. By 10:30 p.m. each Wednesday evening, starting on week two, you should submit ten questions and answers for flash cards. I will try to compile the cards into an Anki deck that I will distribute to you by the end of the day on Thursday.

Students who produce particularly nice decks of flash cards may receive extra credit.

If you find that you prefer physical flash cards to electronic, you should feel free to use the cards we provide at the back of the room.


We will complete labs in class almost every day. You will be asked to submit a subset of the lab work via email for most labs. Your grade on labs will account for 10% of your final grade. Labs will be graded on a complete/incomplete scale. Writeups are due by the start of class on the next day of class. In particular, a lab completed on Monday is due at the start of class on Wednesday, a lab completed on Wednesday is due at the start of class on Friday, and a lab completed in class on Friday is due at the start of class on the following Monday.

If you complete the lab on your own, you must acknowledge your partner’s contributions in your writeup. If you submit the lab together, only one submission is required. However, all group members are jointly responsible for ensuring a submission is made. (For example, if your partner told you he would submit a lab but he forgets to, you will both receive a zero.) For this reason, I recommend submitting labs while you are sitting together and including all named group members in the CC: line of the e-mail.

Submit your lab write-up by pasting the code or answers in the body of an email (do not send an attachment) to by class time the day it is due. If your writeup is not received by class time, it will be considered late.

The subject of the email should be of the form [CSC 151.01] Lab: Lab Title (Names). For example, the class instructors might title a lab writeup on lists as [CSC 151.01] Lab: Lists (Hamid and Rebelsky). Parties to receive credit (i.e., you and your partner’s name(s) if submitting jointly) should also be on the first line of the e-mail.


Your write-up should include your solution to each assigned exercise from the lab. If the exercise directs you to write Scheme code, include your Scheme code. If the exercise directs you to find out what the output of some expression is, copy and paste the output from the DrRacket console. If the exercise asks a question or asks you to explain something, write an answer in English. You do not need to copy the entire lab into your write-up (please don’t!), but do include the problem number for each exercise.


Lab write-ups will be graded on a binary scale, 0 or 1. You will earn a 1 if your write-up includes a solution or evidence of serious effort for each exercise in the lab and a 0 if the write-up was not turned in or if some assigned exercises are not attempted. If you were not able to complete some exercises because of their difficulty, you can still earn full credit by explaining where you got stuck and coming to talk with the instructor as soon as possible. In short, every diligent student should earn full credit for lab write-ups.


A homework assignment is due each Tuesday night at 10:30pm, except when there is a project or exam due. The homework is intended to help you learn and apply some new algorithms and ideas, rather than merely checking that you’ve learned the basic concepts (as the quizzes do). However, they are not intended to be huge undertakings. If you find the assignments are consistently taking longer than 3–4 hours, please talk to me.

I will give you instructions about what forms of collaboration are permitted on each homework assignment, but generally you will be allowed to work with one or two other students from our section.

When you work collaboratively on a homework assignment, only one submission is required. However, all group members are jointly responsible for ensuring a submission is made. For this reason, I recommend submitting assignments while you are sitting together and including all named group members in the CC: line of the e-mail. This also makes it easy for the grader to provide feedback to everyone on the submission.


The course will also include a substantial project, in which you will have an opportunity to exercise your creativity in working on a program over two weeks. I will inform you of the grading rubric when the project is assigned.


Each Friday, there will be a ten-minute written quiz covering one or two key ideas from the previous week. Because lab work is done in pairs, the quizzes are intended to check each individual student’s understanding of these ideas in a timely fashion (i.e., well before the examinations). If you (or the class as a whole) are missing a key concept, I want to revisit that concept as soon as possible so we can build on it in later lessons. Moreover, studies show that testing is a surprisingly effective learning device.

The course schedule includes 12 quizzes; I will drop your lowest quiz grade. Because the goal of the quizzes is to check that you have learned basic skills, an answer that is basically correct will receive full credit, even if there are minor syntax issues. For code, my rule of thumb is that the code is basically correct if I believe you could quickly make it work at the computer (and it uses the required ideas). A partially correct answer will receive partial credit at my discretion.

If you arrive to class late on a quiz day for any reason, please enter as quietly and discreetly as possible. In order to avoid distractions to your classmates, you will receive a quiz with whatever time remains and be asked to submit it with the rest of the class.

Quizzes are considered timed assignments, so if you have an accommodation letter that grants you additional time that is available to you on quiz days. You should meet with me during the first full week of class so we can determine the best way for you to complete the quiz.

Extra credit

To encourage you to support your peers, pursue wellness, and be an active member of the Grinnell community, I will award extra credit points for attending certain events or participating in certain activities. You can earn extra credit for up to eight activities, with no more than four in any broad category (peer support, wellness, academic/artistic), each worth an additional 0.25% on your final grade.


As opportunities for you to demonstrate your programming and design prowess, there will be three take-home exams. The following are their due dates (10:30 PM), though they will be distributed 5-7 days in advance of the due date.

  • Exam 1: February 19, 2019
  • Exam 2: March 12, 2019
  • Exam 3: May 7, 2019

You should find the exams challenge you to go beyond what we have done in class.

Take-home exams are open notes, open computer, and open instructor. However, because I intend the exams to assess your own individual understanding of the material, collaboration on exams is not permitted. You should not talk to anyone (except me) about take-home exams before they are graded and returned. You should not discuss the exam problems (nor your answers) with anyone else. This includes other faculty, class mentors, CS tutors, and any other student, including students who are not currently in this course. You should not give any information about your progress on the exam (e.g., which problems you have completed or which you found difficult), nor should you ask others about their progress. If you have any doubt about what is and is not permissible, ask the instructor.

I will not accept late exams except in special circumstances. If you believe you need to submit an exam late, you must contact me at least 72 hours before the deadline or I will not grant an extension.

Final exam

The final exam can be used to replace your lowest score on one other examination (unless you received a lower score because of a CAS decision). Although the final for this class is optional, you may end up deciding to take it. Therefore I encourage you not to make travel plans that will conflict with your final exam schedule.

Unlike the others, the final will be an in-class exam. Talking with other students during the exam will not be permitted. You may ask me questions. The exam will be closed-book and closed-computer, but you will be allowed to use one double-sided, 8.5x11 sheet of hand-written notes.


Work is due at the time and date specified in the assignment. Each calendar day your work is late will reduce your grade by one letter grade (exams excluded). Work must still be submitted by the due date if you have arranged a prior excused absence.

Because I am concerned about your health and well being, I may also accept late work (exams excluded) if

  1. you start the assignment at least three days in advance of the due date;
  2. you expend a reasonable amount of effort to complete the assignment by the deadline;
  3. you send me an e-mail attesting to facts 1 and 2 with whatever work you’d completed when the assignment is due;
  4. you go to sleep by midnight after sending that e-mail; and
  5. you make an appointment to talk with me immediately about any problems you had on the assignment.

Deadlines for assignments involving programming will automatically be extended by at least one class period if MathLAN is down for an unscheduled period of three or more hours during the two days preceding the assignment due date.

Absolute deadline: All work must be submitted by 5:00pm on Friday, 17 May 2019. This is College policy and cannot be waived for any reason.

Academic honesty

These are abbreviated/shared notes on academic honesty. You should also read my longer notes on academic honesty and the Computer Science Department’s academic honesty policy.

As students, you are members of the academic community. Both the College and I expect the highest standards of academic honesty, as explained in the Grinnell College Student Handbook.

Among other things, this means clearly distinguishing between work that is your own, and work that should be attributed to others. This includes ideas, examples, and code that you draw from labs and readings.

I expect that you will follow the collaboration policies in this syllabus and on each assignment. In particular:

  • When you explicitly work as part of a group or team, you need not identify the work of each individual (unless I specify otherwise).
  • In most cases, you may discuss concepts (algorithms, ideas, approaches, etc.) described in the readings, lab exercises, or during class with anyone.
  • While take-home exams are in progress, you may only discuss class concepts with your instructor, class mentors, and individual tutors.
  • All the work you submit (code, experimental data, write-ups, etc.) must be your own or that of your group. You must appropriately cite any code or documentation you copy or modify, including code provided by the instructor.
  • You must cite all non-syntax consultations (i.e., ideas about algorithms, help with debugging) from any source, including the readings, labs, provided code, and internal or external language references.
  • If you refer to another document when answering a question, cite that document. This principle holds whethery ou’re using the readings, your answers to a previous assignment of lab, a resource you’ve found on the Web, or, well, anything.
  • You must acknowledge and attribute any conceptual contributions by individuals not in your group. That is, you must give specific attribution for any assistance you receive. (This includes from tutors or mentors.) The suggested acknowledgment format is: “[Person X] helped me to do [thing Y] by [explaining Z].”
  • Any program results or output must be faithfully recorded, not forged. (A thoughtful explanation of unexpected behavior can often be a worthwhile submission and is much better than the alternative.)
  • You are responsible for safeguarding your work from being copied by others. This requires you to take reasonable precautions with hard copy printouts as well as file system permissions. (Note that MathLAN’s default permissions prevent others from viewing your files.)

As an instructor, I will meet my obligation to bring any work suspected to be in violation of the College’s Academic Honesty Policy to the attention of the Committee on Academic Standing, after which I no longer have authority over the matter.

Getting help

The Computer Science Department makes tutors for CSC 151 available for help in the open laboratory, SCI 3815. Class mentors also hold weekly mentor sessions, which will be announced in class. Individual peer tutors may also be available for regular, more intensive one-on-one tutoring. As the course gets underway, please let me know if you are interested in regular weekly individual or small-group tutoring. In some cases, I may recommend individual tutoring even if you do not request it.

Of course, you can also get help from me. Please come by during my office hours to discuss the course content, get any extra assistance, or just talk about how the course is going. Note that if multiple students have similar questions or issues, we may work together as a group.

If you cannot attend my scheduled office hours, you may also email me to schedule an appointment; please include multiple possible meeting times (at least two or three) so that I can find one that works for both of us.

I enjoy getting to know my students, but I prefer to reserve office hours for academic matters. If you would like to have a more informal conversation, I would be delighted to accept an invitation to eat lunch with you at the Marketplace, a bag lunch in the CS Commons, or even to take a walk together and chat.

Email is also a reliable way to contact me, but please allow 24 hours for a response during the week, or 48 hours if you send an email over the weekend.