Is UC Berkeley’s CS 70 a Difficult Course?

UC Berkeley’s CS 70, officially titled Discrete Mathematics and Probability Theory, is renowned for being one of the most challenging courses within the university’s Computer Science (CS) and Electrical Engineering and Computer Sciences (EECS) curricula. This course serves as a foundational pillar for students pursuing advanced topics in computer science and engineering, laying the groundwork for subjects such as algorithms, artificial intelligence, and quantitative fields like quantitative finance. This comprehensive analysis delves into the various aspects that contribute to the difficulty of CS 70, explores student experiences, and offers strategies for success.

1. Course Overview

1.1. Course Content

CS 70 is designed to equip students with essential mathematical tools and problem-solving skills necessary for advanced computer science topics. The course is bifurcated into two main areas:

• Discrete Mathematics: This section encompasses logic, proofs, set theory, combinatorics, graph theory, modular arithmetic, and linear algebra. Students learn to construct formal proofs, employ mathematical induction, and engage in abstract reasoning.
• Probability Theory: This portion covers probability spaces, random variables, expectation, variance, conditional probability, and their applications in algorithms and systems. Topics such as Bayesian inference and probabilistic algorithms are also explored.

The course not only focuses on the theoretical underpinnings of these topics but also emphasizes their practical applications in real-world computer science problems, such as cryptography, machine learning, and algorithm analysis.

1.2. Course Structure

CS 70's structure includes a combination of lectures, discussion sections, and homework assignments:

• Lectures: Delivered by experienced professors, lectures cover the theoretical aspects of discrete mathematics and probability theory, providing foundational knowledge and advanced concepts.
• Discussion Sections: These smaller, interactive sessions allow students to engage more deeply with the material, work through complex problems, and collaborate with peers under the guidance of Graduate Student Instructors (GSIs).
• Homework Assignments: Known for their rigor, homework assignments typically require 10–15 hours per week. They involve solving intricate word problems that necessitate written or typed solutions, fostering a deep understanding of the material.

2. Reasons for Difficulty

2.1. Abstract and Theoretical Nature

One of the primary factors contributing to CS 70's difficulty is its abstract and theoretical focus. Unlike programming-heavy courses such as CS 61A (Introduction to Computer Science) and CS 61B (Data Structures), CS 70 emphasizes mathematical reasoning and proof-writing. Students are required to construct rigorous proofs and engage in problem-solving without the immediate feedback that programming offers through code execution.

This shift from computational thinking to abstract reasoning can be challenging, particularly for those who have not previously engaged in proof-based mathematics. Concepts such as mathematical induction, contradiction, and direct proofs demand a high level of precision and logical consistency, which can be daunting for many students.

2.2. Fast-Paced and Dense Curriculum

CS 70 covers a wide array of topics within a single semester, each with its own depth and complexity. The rapid progression through subjects like modular arithmetic, graph theory, and probability theory leaves little time for students to fully internalize each concept before moving on to the next. This fast-paced environment requires students to quickly adapt and assimilate new information, often leading to a sense of being overwhelmed.

2.3. Heavy Workload

The workload in CS 70 is substantial, with weekly problem sets demanding extensive time and effort. Students often report spending between 10 to 15 hours per week on homework alone. These assignments are meticulously designed to test not only the students’ understanding of the material but also their ability to apply theoretical concepts to complex problems. The demanding nature of the homework can lead to significant stress and time management challenges.

2.4. High Expectations and Grading Curve

CS 70 employs a forced grading curve, meaning that only a certain percentage of students can achieve top grades. Typically, only about 15–20% of students earn an A, with average exam scores often hovering around 50–60%. This grading system fosters a highly competitive environment, as students are not only striving to understand the material but also competing against their peers for higher grades.

The combination of low average scores and high expectations can be intimidating, adding to the overall difficulty of the course.

2.5. Competitive Environment

UC Berkeley attracts some of the brightest minds in the world, and its CS and EECS programs are no exception. The presence of highly motivated and academically talented students creates a competitive atmosphere that can be both motivating and stressful. Even students with strong backgrounds in mathematics and computer science may find themselves challenged by the course's rigorous demands.

3. Student Perspectives and Feedback

3.1. Emotional and Academic Challenges

Student testimonials consistently highlight the intense difficulty of CS 70. Common sentiments include expressions of frustration with the challenging homework and exams, the emotional toll of the course, and the significant time commitment required:

• "CS70 is literally so hard."
  Many students express frustration with the dense material and demanding assignments. For instance, a student on Reddit stated, “The material is so dense and the notes are super long and dense. I don’t think the homework or discussion worksheets are very helpful in learning the material because they are so hard” (source).
• "Why is CS70 this hard?"
  Another student shared feelings of being overwhelmed despite extensive effort, saying, “I’ve gone through notes again and again, watched lectures by both Rao and Professor Umesh Vazirani, attended lectures in person still, and even joined a study group… It feels like this class is eating my soul” (source).
• "CS 70 kicked my ass."
  A vivid anecdote on Reddit described a student being so distressed by a midterm that a friend mistook their distress for a personal loss (source).

These experiences underscore the substantial academic and emotional challenges associated with CS 70, as well as the sense of camaraderie that often develops among students navigating the course's difficulties.

4. Strategies for Success

Despite its reputation for difficulty, many students successfully complete CS 70 by employing effective study strategies and leveraging available resources. Here are some key approaches:

4.1. Forming Study Groups

Collaborating with peers through study groups can significantly enhance understanding and problem-solving abilities. Students often find that discussing concepts and working through problems together fosters a deeper comprehension of the material and provides emotional support during challenging times.

4.2. Consistent Attendance and Participation

Regular attendance to lectures and discussion sections is crucial. Active participation helps reinforce learning, clarify doubts in real-time, and keep pace with the fast-moving curriculum. Engaging with the material consistently prevents falling behind, which can be detrimental in such a rigorous course.

4.3. Utilizing Office Hours

Taking advantage of office hours offered by professors and GSIs provides personalized assistance with difficult concepts and assignments. Asking questions, seeking clarifications, and getting feedback on problem-solving approaches can greatly aid in mastering the course material.

4.4. Practicing with Past Exams and Problem Sets

Working through past exams and additional practice problems is one of the most effective ways to prepare for assessments. This practice not only familiarizes students with the exam format and question styles but also reinforces the application of theoretical concepts to practical problems. The course website often provides access to previous exams, which can be invaluable for study purposes (source).

4.5. Focusing on Understanding Over Memorization

CS 70 emphasizes deep understanding of concepts rather than rote memorization. Grasping the underlying principles allows students to apply knowledge flexibly to novel problems, which is essential for both homework and exams. This approach fosters critical thinking and problem-solving skills that are valuable in advanced studies and professional settings.

4.6. Effective Time Management

Given the heavy workload, effective time management is paramount. Students should create a study schedule that allocates sufficient time for lectures, homework, review sessions, and breaks. Especially in summer classes where the pace is even more accelerated, managing time efficiently helps in keeping up with the condensed curriculum.

4.7. Seeking External Resources

If internal resources such as lecture notes and discussion sections are insufficient, students can turn to external resources like textbooks, online tutorials, or tutoring services. Supplementing course materials with additional explanations and examples can aid in overcoming difficult topics.

4.8. Taking Care of Mental and Physical Health

The stress associated with CS 70 can take a toll on students’ mental and physical well-being. It is crucial to maintain a balanced lifestyle by taking breaks, getting adequate sleep, and seeking support when feeling overwhelmed. Maintaining overall health contributes to better academic performance and resilience.

5. Comparison to Other Courses

When compared to other challenging courses at UC Berkeley, such as CS 61A and CS 61B, CS 70 stands out due to its intense focus on mathematical rigor and abstract reasoning:

5.1. CS 70 vs. CS 61A and CS 61B

• CS 61A (Structure and Interpretation of Computer Programs): This course is heavily programming-focused, introducing students to computational thinking through programming assignments and projects. While challenging, it offers immediate feedback through code execution.
• CS 61B (Data Structures): Similar to CS 61A in its programming intensity, CS 61B delves into data structures and algorithms, with a mix of programming assignments and theoretical concepts.
• CS 70 (Discrete Mathematics and Probability Theory): Unlike the programming-centric courses, CS 70 requires students to engage in abstract mathematical reasoning and proof-writing. The lack of immediate feedback mechanisms, such as those provided by programming assignments, can make the learning process more challenging.

While CS 61A and CS 61B focus on computational problem-solving, CS 70 demands a deep understanding of mathematical concepts and the ability to apply them in theoretical contexts, making it uniquely challenging.

6. Is CS 70 Worth It?

Despite its formidable reputation, CS 70 is considered highly valuable for students pursuing computer science and engineering disciplines:

• Foundation for Advanced Topics: The mathematical tools and problem-solving skills acquired in CS 70 are essential for upper-division courses such as CS 170 (Algorithms), CS 188 (Artificial Intelligence), and quantitative finance-related subjects.
• Development of Critical Skills: The course fosters critical thinking, resilience, and the ability to tackle complex problems—skills that are invaluable in both academic and professional settings.
• Preparation for Technical Interviews: The rigorous problem-solving and analytical skills honed in CS 70 are highly beneficial for technical interviews in the tech industry.

Moreover, successfully navigating CS 70 serves as a testament to a student’s capability to handle challenging material, which can be advantageous in competitive academic and career environments.

7. Conclusion

In summary, UC Berkeley’s CS 70 is undeniably a difficult course, characterized by its abstract and theoretical nature, fast-paced and dense curriculum, heavy workload, high expectations, and a competitive environment. Student feedback consistently reflects the intense challenges posed by the course, both academically and emotionally.

However, the difficulty of CS 70 is balanced by the substantial rewards it offers. The course provides a crucial foundation in discrete mathematics and probability theory, which are indispensable for advanced studies and careers in computer science and engineering. By adopting effective study strategies—such as forming study groups, utilizing office hours, practicing with past exams, and focusing on deep understanding—students can successfully navigate the challenges of CS 70.

Ultimately, while CS 70 is challenging, it is also one of the most rewarding courses at UC Berkeley for those committed to developing a strong mathematical and theoretical foundation in computer science.