We received 11 contest entries this quarter and were impressed by the creativity and probability know-how the entries showed!

Winner: Derek Chong, Modernizing Community Moderation

Runner Up: Soraya Fereydooni, Extra Credit Project

Honorable Mention: Joshua Shongwe, Judicial Perspective on Systemic Privilege

Honorable Mention: Andrea Pasinetti, Using Data on Student-Teacher Ratios and School Capital Investments to Predict Educational Outcomes for Middle and High School Children in New York State

The final problem set is now available. You will implement two machine learning algorithms, Naive Bayes and Logistic Regression. You will then use these algorithms to make predictions on heart tomography, Netflix movies and ancestry.

Quiz #2 is released. Your personalized PDF is available here. If you have issues downloading your PDF, please email the staff mailing list (cs109 @ cs.stanford.edu) or post privately to Edstem so that we can email you your exam as soon as possible. The LaTeX template is available here.

This take-home, open-book, open-notes exam is to be completed individually, and is due on Thursday, 5/21 11:59pm Pacific time.

The quiz should correspond to about 2 hours of active work time (plus any typesetting). The Gradescope assignment submission portal will be up through the end of the 24-hour window, so please make sure your final submission is uploaded by then. Also please make sure to tag your PDF submission pages to each question answered.

If you have an emergency situation where you are unable to set aside a few hours to complete the exam in this timeslot, please email Lisa and Cooper at any time. We will try our best to accommodate you.

Good luck!

The penultimate problem set is now available! This problem set has only 8 questions (plus extra credit).

How are you doing so far? Please fill out an anonymous feedback form here: https://forms.gle/DnWbEd5G95Dm5muF9. We'll keep the form open through Friday night, May 15.

We have adjusted the grading rubric as follows (more info in Administrivia handout and EdStem Discussion). To get a satisfactory grade in this course, you must:

• Present passing work on 6 of the 7 following components: Problem Sets 1 to 5, Quiz 1, and Quiz 2;
• Present passing work on Problem Set 6; and
• Have a weighted final course grade of at least 65%.

Quiz #2 for CS109 is coming up: It is Thursday, May 21st, 12:00am-11:59pm Pacific. It should correspond to about 2 hours of active work time. The quiz will cover material up to and including lecture 17, which includes up to part of Problem Set 5. PS5 will be released by tomorrow so that you have extra practice. Practice exams, section handouts, and psets are all great ways to study.

Review session: Tim, one of our outstanding TAs, will be hosting a review session on Saturday, May 16th, 12:00pm-2:00pm Pacific, accessible via this Zoom link. The session recording and materials will be posted on the quiz website afterwards.

If you have an emergency situation where you are unable to set aside a few hours to complete the exam in this timeslot, please email Lisa and Cooper at any time. We will try our best to accommodate you.

If you're looking for older concept checks to aid your studying, we've included links to PDFs of them down below in the schedule.

Errata (May 10): The starter code has been updated to fix an error with probSymptom(i, f, c). Please re-download the starter code if you have already started working on the coding question. Thanks!

Problem Set #4 has been released! It has you predict flu or cold based on binary symptoms and risk factors.

This quarter we are going to hold the sixth Stanford Probability for Computer Scientists Contest. The contest is completely optional and is intended to replace any passing work requirement in this course. See the contest handout for more details.

Optional proposal deadline: Saturday, May 23, 11:59pm Gradescope form
Final contest deadline:Monday, June 8 11:59pm

Quiz #1 is released and on the exam page. The take-home, open-book, open-notes exam is to be completed individually, and is due on Thursday, 4/30 11:59pm Pacific time.

The quiz should correspond to about 2 hours of active work time (plus any typesetting). The Gradescope assignment submission portal will be up through the end of the 24-hour window, so please make sure your final submission is uploaded by then. Also please make sure to tag your PDF submission pages to each question answered.

If you have an emergency situation where you are unable to set aside a few hours to complete the exam in this timeslot, please email Lisa and Cooper at any time. We will try our best to accommodate you.

Problem Set #3 has been released! It uses real probability density functions from the IPCC Climate Change report, and has you analyze a bloom filter (a probabilistic datastructure). We're releasing this problem set early to give you more practice for the quiz. It is due post-quiz, Friday, May 8, 10:00AM Pacific Time.

Quiz #1 for CS109 is coming up: It is Thursday, April 30th, 12:00am-11:59pm Pacific. It should correspond to about 2 hours of active work time. The quiz will cover material up to and including lecture 9, which includes Problem Sets 1, 2, and part of Problem Set 3. PS3 has been released early so that you have extra practice.

The best way to study is to work through the practice exams and section handouts. This website also has quiz administration details.

Review session: Tim, one of our outstanding TAs, will be hosting a review session on Tuesday, April 28th, 12:00pm-2:00pm Pacific, accessible via this Zoom link. The session recording and materials will be posted on the quiz website afterwards.

Update (4/28): Review session recording is here, and review session whiteboards are here.

If you have an emergency situation where you are unable to set aside a few hours to complete the exam in this timeslot, please email Lisa and Cooper at any time. We will try our best to accommodate you.

Sandra, one of our outstanding TAs, will be hosting the second of three Python help sessions covering concepts, tips and tricks for Problem Sets 2 and 3. IT will be held this Friday, April 24 at 5:00pm - 6:00pm Pacific. You can join the session at this zoom link and we will post the recording afterwards. Here is a link to the Jupyter notebook in case you want to get started.

Update (4/26/20): The session slides and Zoom recording are now up on the Python page..

The first of three Python help sessions will be held this Friday, April 10 at two different times to accomodate students: 12:30am - 1:30am and 1:30-2:30pm Pacific. These times are on the CS109 calendar and you can join the session at this zoom link.

Please make sure you have installed or attempted to install Python per this website guide to Python. During the session we will be covering Python language basics, important Python libraries, and get you set up to start Problem Set #1. There will be a Q&A and debugging setup session at the end. The meeting will also be recorded and posted on Canvas after the fact for those who cannot make it live. Looking forward to seeing you all there!

Update (4/10/20): The session slides and Zoom recording are now up on the Python page..

Problem Set #1 has been released! It is due next Friday, April 17 at 10:00am Pacific. Submission will be via Gradescope with entry code M2YZ88. Office hours will start today, and the office hours calendar will have times and Zoom links.

You are encouraged to write up your problem sets using LaTeX. Templates for each Problem Set are located on their respective webpage. See this installation guide and intro to LaTeX. Though you may install LaTeX, it is often much easier to use an online LaTeX editor. A great option is: overleaf.com.

Thank you for everyone who filled out the optional course planning survey! You can still fill out the form (we are also still reading the jokes you contributed).

The exact details of this course will be available in an Administrivia document to be posted over the weekend, but for now we've written up answers to commonly asked questions regarding prerequisites/whether this course counts towards degree requirements/what fluency of Python/LaTeX is needed/whether lecture/section attendance is mandatory: FAQ link. Stay tuned for the first day of class for more details

Welcome to CS109! We are looking forward to a fun quarter. Class starts Monday, April 6, at 10:30am PT Online. Online Zoom lectures will be recored and posted to Canvas if you cannot attend the live sessions. More details to be released soon!

Course planning survey: To help us help you in this exciting Spring 2020 online-only quarter, please fill out this survey form that asks for your timezone, your technological accessibility situation, and your course expectations. This form is completely optional and is intended to inform how we can better structure CS109 to meet your learning goals and accessibility needs this quarter.

Course schedule: The Course Schedule page shows you the topics that we are going to cover in CS109 and the corresponding readings. We will also post materials from lecture on the schedule page.

Once the quarter starts, you will need to sign up for a weekly 50-minute discussion section. Details on how to sign up for section will be provided during the first week of class.