Syllabus

Stat 20: Introduction to Probability and Statistics

Instructor

Jeremy Sanchez

Term

Summer 2025

Course Goals: To introduce descriptive and inferential statistics, basic probability theory and prediction problems using both pen-and-paper and computational approaches (with the R language and particularly with the tidyverse library). In essence, STAT 20 is an introductory statistics course which also has a lens for data science.

Course Culture

This course is designed to teach students who have never done statistics or have done any type of computer programming before! There are no stupid questions, and we will not tolerate behavior which discourage students from asking questions. Everyone starts somewhere.
Discrimination/harassment based on race, gender, ethnicity, sexual orientation, or anything else will not be tolerated.
Academic dishonesty will also not be tolerated. We will take any violations of academic integrity to the Center for Student Conduct, in addition to any grade penalties that ensue. Repeat violations will result in failure. There is more on this later on the syllabus.
Berkeley Honor Code:
- As a member of the UC Berkeley community, I act with honesty, integrity, and respect for others.

Websites to know

bCourses: Announcements will go out here.
Course website: All course materials, including readings and assignments, will be available at https://stat20.berkeley.edu/summer2025. You do not need to buy any materials for our course!
RStudio: The computing platform you will use this semester. As a Berkeley student, you have your own version of RStudio waiting you for at: http://stat20.datahub.berkeley.edu. Most students taking Stat 20 have no experience programming; we’ll teach you everything you need to know!
Ed: The class discussion forum. Here you may ask questions about course content, or, via the private feature, message myself and the staff about something personal. If you have a message you’d like only the instructor to see, email the instructor or use bCourses to contact the instructor.
Gradescope: You will turn in your assignments here.

Format

For the most part, STAT 20 operates in the flipped classroom format. This means that you will read about the topics in class the night before they are discussed, so that class time can be spent working on the class assignments and asking questions about the material to myself and the group tutors.

First portion of class

You will test your knowledge of last night’s reading by answering a few reading questions on the PollEverywhere service.

Second portion of class

We will work on your portfolios and labs together.

Traditional format

The traditional, lecture-style format will be used for the probability unit, as I have found through experience that probability is difficult on the students when presented in the flipped format.

Assignments

Assignment	Percentage
Reading Questions	2
Portfolios	5
Labs	15
Quizzes	45
Final	33
Extra Credit	1
Total	101

You can check the assignment schedule here.

Reading Questions

How many: 17
Deadline: completed during class.
Weight: equally weighted.
Drops: 3

For most lecture topics, you will be asked to read the corresponding section from the course textbook the night before it is discussed in class (or over the weekend). You will then answer two or three short reading questions the next day in class for a small percentage of your grade. You may work with those sitting next to you. The questions are not meant to be difficult (you will have a very short time to answer them) and are just to check your understanding from the night before. We’ll go over each of them once you have finished answering.

Worksheets and Portfolios

How many: 7 (3-4 worksheets per assignment)
Deadline: generally, weekly on Fridays at 5pm.
Weight: equally weighted.
Drops: 1

Every week, you will be given a set of worksheets: one per each class day. A portfolio consists of all of the worksheets from a given week together. Each portfolio is of equal weight. You will turn in a given week’s portfolio at once. You will not be graded on accuracy, as the problems are meant to be practice for you. Give each worksheet in the portfolio an honest attempt and you will receive full credit for the whole portfolio. We will be spending class time on the worksheets. There will be printed copies in class as well as the digital version online for tablet users. To turn in your portfolio on Gradescope, you may either scan your written worksheet or submit the digital version. Solutions to the portfolios will release the week after they are due. Therefore, no extensions may be requested on this kind of assignment.

Labs

How many: 4
Deadline: generally, biweekly on Fridays at 5pm.
Weight: The first lab is worth 10 percent of the total lab grade. The next three labs are each worth 30 percent of the total lab grade.
Drops: 1

Every two weeks, you will turn in a project which focuses on a specific dataset; these projects are called labs. There are two parts to the lab: a written part and a coding part. We will also give you class time to work on the lab. I cannot release solutions to the labs; however, you may certainly come to office hours and ask about any points you missed.

We will be sending out an Ed post about how to format your lab submissions on Gradescope, and we’ll also go over how to format the submissions within the first week. Please read this post/pay close attention in class, as you will lose points if your work is incorrectly formatted. The first lab is primarily meant to walk you through this process.

Quizzes

How many: 3
When: every two weeks.
Weight: equally weighted.

Quizzes are 40-minute, in-person examinations that cover the previous two weeks of material. The quizzes have a fun format which is detailed below.

Individual Portion (25 minutes)

You will take the quiz on your own.

Group Portion (15 minutes)

You will retake the quiz in a group of size 2 or 3. The group is of your choosing. The goal is for you to learn from each other’s mistakes.

How is your final quiz score calculated?

The final quiz score is the average of the individual and group portions. Make sure to pick a group that you trust.

Extra Credit

You’ll have an opportunity to earn some extra credit during the final week of the course. Stay tuned for more details :)

Final

You will have a cumulative, final exam on Thursday, August 14th during class-time. This is a date you will want to mark on your calendar.

Grade calculator

A grade calculator for the course is here. Feel free to make a copy and put in your own grades! The calculator does not have drops, but you can feel free to alter the copied spreadsheet to add them. We use the standard grading bins. In the event that the bins change, they will only change to help, not to hurt, students. Consult Berkeleytime for previous grading distributions, and do not ask group tutors about grading (they do not grade your assignments).

Other policies

Accomodations for students with disabilities

Stat 20 is a course that is designed to allow all students to succeed. If you have letters of accommodation from the Disabled Students’ Program, please share them with me and we will work out the necessary arrangements. This includes extensions on assignments or anything else!

Late Work and Drops

One day late: 30% off your total score.
Past one day late: no credit.

If you need to request a extension on a Lab, please send a message on private Ed with at least one day before the deadline to spare. All Lab extensions will be two days by default. If you have a serious emergency (such as a visit to the ER) that prevented you from filling out the form on time, let me know via e-mail. For Lab extensions longer than three days, such as in cases of long-term illness or emergencies, come to office hours or set up an office hour by appointment with me or e-mail me.

Within a given assignment category, a drop(s) will be automatically applied to the lowest-scoring assignment(s).

Collaboration policy / academic dishonesty

These are policies that are most important, but note that we reserve the right to identify punish other dishonest behaviors (the list is not exhaustive).

Labs and Worksheets

You may collaborate with your fellow students on Worksheets and Labs, but:
- you must turn in your own work.
- you must cite those that you worked with at the beginning of your document in writing or otherwise.
You may complete Labs using only code that we have taught you in the course.
You shall not leave a representation of your assignment (the text, a screenshot) where students (current and future) can access it. Examples of this include websites like CourseHero, on a group text chain, over discord/slack, or in a file passed onto future students.
You shall not use past solutions to an assignment.
You shall not use generative AI to answer Lab questions.

Examinations and Reading Questions

Quizzes: During the group portion of a Quiz, you shall not collaborate with those outside your Quiz group. The individual portion of the Quiz is entirely your own work.
Reading Questions: you shall not collaborate with those not at your table.
Final: The final is entirely your own work.

Frequently Asked Questions

What should I do if I’m on the waitlist?

Attend as if you were a student and submit all assignments on time, and you should get in! Also, talk to me on the first day of class so you can be added to the course Ed and Gradescope.
Are class sessions recorded?

They will not be. The online textbook is the main source material for the course, and any materials used during the class session, such as slides and other items, will be posted to the course website.
Is attendance required?

Strictly speaking, no. However, it will be difficult to succeed in this course if you are not regularly attending class. If you can’t attend due to a religious observance, athletic competition, or something similarly important, don’t worry. Just reach out to us via private Ed or e-mail, and we can let you know what to keep tabs on during the time you’re away.
Stat 20 does not allow students to enroll with time conflicts.
What if I join the class late?

If you join the class within the first two weeks, read the syllabus and textbook, and take a look at Gradescope to get a sense of any assignments that may have already passed. Another good idea is to visit office hours. The first two weeks of material are very important, so you must be able to make up assignments.

If you want to join after two weeks of the semester have passed, you will have to take STAT 20 in a subsequent semester.

Campus Resources

It can be very tough to be a student at this school! There are applications to clubs and grade requirements to declare majors, which are two things I did not have to experience as an undergrad. Some of you are navigating other challenges, like being a parent or commuting long distances from home to campus. There’s also that pervasive impostor syndrome. I’ve learned these things from my students during my time so far here teaching, and if you have any other things you’d like to share with me about your experiences or if you just need someone to talk to about your academic struggles or your future path, I can be there for you.

With regards to reports of sexual misconduct/violence/assault, you may speak with us as well, but know that we will need to report our discussion to the Title IX officer. This is detailed below.

As UC employees, I and the tutors are “Responsible Employees” and are therefore required to report incidents of sexual violence, sexual harassment, or other conduct prohibited by University policy to the Title IX officer. We cannot keep reports of sexual harassment or sexual violence confidential, but the Title IX officer will consider requests for confidentiality. Note that there are confidential resources available to you through UCB’s PATH to Care Center, which serves survivors of sexual violence and sexual harassment; call their 24/7 Care Line at 510-643-2005.

Below are some campus resources that may be helpful for you: