Homework Policies
This page explains what homework assignments are for and how they are marked. Please do read What Homework Are For — the rest is logistics, but that part changes how you should use them.
What Homework Are For
Previous offerings of this course had a problem, and it was mine, not yours. You were assessed with 25-minute closed-book quizzes asking you to write out a model, define a property, or read a diagnostic plot. The only practice you got was homework — but homework then meant a two-week computational assignment, where you had a laptop, the internet, your classmates, and fourteen days. Those measure different things, and only one of them was being practiced.
So homework in this course is a different animal from what that word used to mean here: nine short assignments rather than five long ones, mostly on paper, in the format the quiz actually uses.
Homework close that gap. They are in the quiz’s exact idiom — same question forms, same expectation of a written answer, same absence of a computer for most of it — at about 1.3 times a quiz’s length. If you can do the homework assignment, you can do the quiz. That is the entire design.
A homework assignment is worth about 2% of your course grade. It is not there to sort you; it is there to tell you — before the quiz, while it is still free — whether you can actually write out a null model or read an ACF. If you look at the key before attempting the problems, you will get the satisfying feeling of understanding and none of the actual understanding. I have seen this go wrong many times, and it always goes wrong the same way.
Structure
Each assignment is worth 20 points and should take about 45 minutes: roughly 30 minutes of written work and 15 minutes at the keyboard.
| Problem | Points | What it is |
|---|---|---|
| Problem 1 | 7 | A short scenario with three sub-parts, walking the loop on one object |
| Problem 2 | 7 | Three standalone short questions, exactly in the quiz’s format |
| Problem 3 | 6 | The computational item, ending in a figure and a sentence of interpretation |
A homework assignment is 20 points and about 45 minutes. A quiz is 6 points and 25 minutes. A homework point is therefore worth roughly half a quiz point — homework is open-book, untimed, and scored at finer granularity, so a point buys less. Do not read “20 points” as three quizzes’ worth of work. If an assignment is taking you dramatically longer than 45 minutes, that is useful information and I would like to hear about it.
Logistics
- Homework are due at 9:00pm Eastern on the due date, which is always a Friday. Submit to Gradescope as a PDF with pages tagged. Failure to tag pages results in a non-negotiable 10% deduction.
- Late submissions are accepted up to 24 hours, at full credit.
- The solution key posts when the late window closes, one day after the deadline. No submissions are accepted after the key is public.
- The lowest homework assignment is dropped automatically.
- Collaboration is encouraged. Write up your own answers in your own words, and list who you worked with.
How They Are Marked
Every question is checked against the posted key. Two or three questions per assignment additionally receive written feedback.
Why the difference? Because a posted key and a grader do different jobs. If you defined the logit incorrectly or got the sample-size calculation wrong, the key tells you that, and a paragraph from the TA adds nothing. What a key cannot catch is reasoning that is plausible and wrong — and that is exactly what happens on questions like “why can two defensible null models give different p-values?” Those answers can read perfectly well and be wrong, and only a human notices. So written feedback goes where the key is insufficient.
Which questions get written feedback varies from week to week and is not announced in advance. This is deliberate: if you knew, you would optimize for those two questions, which defeats the purpose.
Problem 3 is not optional garnish. An assignment submitted without a serious attempt at all three problems, including the computational one, does not receive credit — it is not marked out of 14.
This is the only thing in the course keeping your hands on a keyboard between mini projects, and the wrangling it asks for (grouping, joining, handling gaps) is a skill this course expects you to build through practice rather than lecture.
Answers, Not Output
For the computational item specifically:
- Answer in sentences. Raw program output pasted into a PDF is not an answer to anything.
- Label your figures. Axis labels with units, a legend if there is more than one thing plotted. A figure that needs you standing next to it to explain is not doing its job.
- Avoid excessive precision. If you report a return level as 3.847261 m, you are claiming something about the sixth decimal place that your 40 years of data cannot support.