Exams and Homeworks

Exams

Midterm exams will be in class meetings, as indicated on the Class Schedule.

Remember that your work will be graded primarily on the quality of your written reasoning. This includes:

the clarity of your thinking, as I can confidently infer it from what is written;
the validity of your arguments;
completeness of your arguments (clearly showing all important steps); and
the clarity of your exposition.

Having the correct numerical value or result at the bottom of the page is not equivalent or sufficient.

Related notes:

A more efficient solution using (the intended) more powerful methods from the course demonstrates better proficiency and is better reasoning, so to get full credit you should think about the intention of the question and the BEST way to solve it.
The instructor will infer your reasoning from exactly what you have submitted in writing, so make sure that you document all aspects of your reasoning that are relevant to the ideas of this course.
It is important that you disavow (cross it out) mistakes! This includes typos, realized errors, attempts that didn't work,... anything on the page that is not representative of the final form of your reasoning. It is fine of course to try something that ends up not working out or not making sense, but if you leave it on the page without crossing it out then you are presenting it as being representative of your understanding. If you aren't sure if it is right or wrong, you have to choose one way or the other -- it is not reasonable to expect to be able to gain points if it ends up being right without also being able to lose points if it ends up being wrong.
Graders are more likely to assess your explanations more generously if those explanations track the way ideas are presented in official course materials (the textbook, the class notes, the lectures,...). This advantage is a natural result of the simple fact that we know these resources and we know how you were exposed to them, and so it is easier to identify what valid ideas a potentially weak exposition might be attempting to describe and then to give the student a resulting benefit of the doubt. The other side of this is that you should NOT rely on outside resources such as in other books or online. Even if there is validity to what you find there, unavoidably you lose the advantage noted above. It is fine of course to look at outside resources as tools for helping you to understand the ideas in the official course materials, but you should not view them as alternatives or substitutes to course materials.
Clarity of exposition is essential in using math in practice, and is also natural evidence of good understanding of the ideas at hand. An obvious and important part of such clarity is the avoidance of ambiguity, and one part of this is the proper use of mathematical notations and terminology, consistent with their usage in the official course materials. The notations and terminology used in the course materials should be sufficient for all course work, and you are strongly urged to stick with these. If you use notations or terminology from outside sources, you are taking a risk -- they might be okay, but there are several ways that they might not be -- so this is not advisable. And of course you are taking an extreme risk if you just make up your own notations or terminology! :) If you feel you have a compelling reason to use notation or terminology that is not in the official course materials (and this should be unlikely), be sure to check with the instructor first to make sure that there isn't a problem that you might not be aware of.

This is a high bar, and of course there is a great amount of material in this course. So you should not plan to "study for the exam" in the few days preceding. Rather, you should think of studying for the exam as something that you do continually through the term. After every lecture you should immediately begin in earnest on the relevant homework exercises, seek out help from the various course resources on the exercises you are not sure about, and then with the homework complete start working immediately on polishing your proficiency on that material in preparation for the exam. The more timely the better, of course -- because the sooner that you maximize your proficiency on one topic, the more that proficiency will help you as you learn new topics that depend on it. Ideally, you should aim to go into every lecture already prepared to take an exam on the material from the previous lecture.

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On exams in this course, the exam packet must remain intact. You may not remove the staple, tear pages out of the staple (not even the scratch sheets!), or tamper with the exam packet in any way. Any such tampering can cause serious problems with the scanning process.

Work for a given question can be done ONLY on the front or back of the physical page the question is written on. Room for scratch work is available on the back of the cover page, and on the two blank pages at the end of the packet; scratch work will NOT be graded.

On exams in this course you must use black pen. This is because pencil does not scan well with stack scanners, and so work written in pencil will not be legible in Gradescope (and similarly for other colors of pen). Of course you won't be able to erase, but as noted above anything scratched out will be viewed as disavowed and will not be held against you. If you are concerned you might not have enough space, keep in mind the above notes about the backs of pages, and scratch pages. You may use a pencil for initial sketches of diagrams (only!), but the final sketch must be drawn over in black pen and you must wipe thoroughly all erasure residue from the paper.

You may use a straight edge to assist in your drawings, but ONLY if there is zero mathematical content on the item.

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If on the day of a midterm exam you are incapacitated due to illness, you must send to your instructor an Incapacitation Form (commonly called a "Short Term Illness Notification Form", or the acronym "STINF") before the scheduled exam time (unless that is not possible) in order to be excused. Please also document the nature of your condition in that STINF, or in a separate email. Note also important related discussions and references at the course website / General Policies / Short Term Illness.

Importantly, note that final exams are treated differently by Duke -- the incapacitation form will be disabled and any possible excusals must come from the student's academic dean. See details on this in the section "Absence from a Final Exam" on the T-Reqs page on Health Issues. Note, by the use of the term "extraordinary circumstance" in that discussion, you cannot assume that the dean will agree to excuse your absence.

Other than incapacitating illnesses as discussed above, excusals from midterm exams are generally given only in cases of university representation (e.g. travel for Duke's athletic teams) and religious observance (as recognized on Trinity's policy pages), per university policy. Other cases that would be excused are rare, and the student should be sure to obtain the instructor's excusal (which should not be assumed!) in writing before making any such conflicting plans; and having already made such plans before requesting such an excusal will not influence the instructor's evaluation of the request.

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Once the exam is marked and scored, your work will be returned to you through Gradescope. Your instructor will announce how scores on that specific exam can be interpreted on the 4-point scale (this conversion will be different for every exam, appropriate to the instructor's assessment of the difficulty of the exam).

All regrade requests must be submitted through Gradescope. The instructor will announce the window for submitting regrade requests when your work is returned; typically it will open about one day after your work is returned, and (for exams) will close about one week after your work is returned (or at the start of the final exam, whichever comes first). No late regrade requests are accepted. The instructor will give full and fair consideration to all submitted regrade requests as soon as they can. NB, the purpose of regrade requests is to give students the opportunity to point out objective errors in the grading (as these do happen sometimes), and they will be considered with the goal in mind of scoring the work accurately and fairly by the same standards that were applied to all other papers. Regrade requests are not likely to result in more points if they are not based on what was explicitly written on the exam paper, or if they are based on subjective interpretation of what is written, or if they are based on a disagreement about the standard of grading used for the question. Keep in mind also that, with the goal being accuracy and fairness, there is no guarantee that the resulting score won't be lower than the initial one, so you should submit a request only if you are confident that there has been an actual error in the grading.

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Students with SDAO accommodations should be sure to send their official accommodation letter to me as early as possible in the semester. In the interests of fairness to all students and in recognition of SDAO's authority on such matters, accommodations are given only to students for whom I have received an official accommodation letter from SDAO.

I will communicate detailed policies and procedures for testing accommodations to all such students in my class usually just a bit before the first midterm exam, but I welcome questions in advance if you are wondering roughly how things will work in this class. NB in most cases I do NOT use the Testing Center, so please do NOT request appointments with the Testing Center (unless I explicitly direct you otherwise).

Homeworks

For each homework assignment, the sections assigned are indicated on the Class Schedule; the exercises assigned are those on the Content Syllabus for those indicated sections. The due dates are also listed on the Class Schedule. All homework assignments will be submitted, graded, and returned through Gradescope.

Unexcused late submissions are not accepted. (The "late due date" indicated on Gradescope is there ONLY for students who have been excused.) Typically, excusals are given only in the cases of illness (Incapacitation Form), university representation, religious observance, and rare/compelling circumstances (such as a siblings wedding out-of-state).

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Gradescope works best with PDF submissions (please do not submit with JPG's!), and for most students the easiest way to do this will be by doing your initial work with pen and paper, and then using a scanner app to create the PDF. I have used Cam Scanner for the past several years and recently switched to Adobe Scan, and have found both to be effective and easy to use -- but there may be better apps and you are encouraged to find the one that works best for you. Using a tablet to create your PDF files directly is also acceptable for homework assignments, but be advised that this will NOT be allowed on the exams, and we advise you to do homework exercises on paper as part of helping you to prepare for the exams.

It is strongly advised that you spend some time learning how to use your scanner app most effectively. Issues that you should think about include getting good focus, avoiding glares, having sufficient lighting, cropping appropriately, getting sufficient resolution, and keeping file sizes reasonable. Again, gradescope works best with PDF submissions. Consider using the B&W or grayscale option with your scanner app to reduce file sizes while keeping good resolution. Be sure to have these issues all in mind as you do your scans and make sure that you will be able to submit a PDF in which all of your work is clearly legible.

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We do not have sufficient staff to grade all of the exercises on the homework. For each assignment, only a subset of those exercises will be graded (each out of 10 possible points), one from each of the submission groups designated for that assignment. When you submit your work for a given assignment, Gradescope will ask you to associate pages of your work to each submission group -- when you do, be sure to include all pages showing work for the listed exercises for that group. These page associations are critical to how the graders do their work. Upload with pages not associated correctly are not complete submissions; they might not be accepted by the head grader, or points might be deducted.

See the Class Grades section for information on how to interpret these scores on the 4-point scale. Similarly to exam grading, submissions of homework exercises are graded significantly for the quality of the reasoning -- not just the final answer -- so be sure to show your work and that your thought process is clear from what you have written. I encourage you to think of the homework exercises as being practice for the exams, so think about exam grading standards (see the Exams section of this page) as you work.

All regrade requests must be submitted through Gradescope. The window for these requests will typically open about one (business) day after your work is returned, and (for homeworks) will close about one week after your work is returned (or at the start of the final exam, whichever comes first). No late regrade requests are accepted. The homework graders will give full and fair consideration to all submitted regrade requests as soon as they can. See additional notes about regrades in the Exams section above.

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If an incapacitating illness prevents you from getting the homework submitted on time, you must send an Incapacitation Form to your section instructor in order for your late submission to be accepted and graded. Please be sure that your Incapacitation Form documents the nature of your incapacitation. If you submit your work on Gradescope late (the official due time is that indicated on the Class Schedule -- do not confuse this with the "late submission" date which may also be visible on Gradescope) without being excused by your instructor, it will not be graded and you will not receive credit for the work.

Calculators and Computers

Your homework assignment submissions may not include any references to or have any reliance on work done on a calculator or a computer, except on exercises that specifically instruct you to use such tools. You may use such tools to help you gain an understanding of an exercise, but then your written solution to the problem must be done entirely independently. The only rare exceptions to this policy would be exercises for which exact expressions would not be feasible to work with.

For the few exercises that do specifically instruct you to use a computational tool, you may use any computational tool you prefer. I discourage the use of hand calculators though, because their continued use is largely a result of institutional momentum and they are very unlikely to be in use in professional contexts. Also, note that Pratt prefers for their students to use either Matlab or Python. On these exercises, your submission should show (1) your input into the machine, (2) the output from the machine, and (3) your analysis/explanations that relate these to the original question and to the final answer (there should always be some of this -- even if it is trivial or obvious). You might submit this by printing the machine input and output and then annotating your analysis on that paper, or you could annotate electronically, or you can even just scan the computer screen showing the computer input and output as you are also scanning your other work on paper.

Calculators and computers will NOT be allowed on the exams. Since one of the primary purposes of the homework exercises is to help students learn the material in preparation for the exams, it is advisable to use calculators and computers sparingly while working on the homeworks.