Courtesy of Charlie Liu

For those enrolled in Yale’s “Introduction to Computing and Programming,” it is fairly common to get stuck while coding. This year, students will have access to a new personal tutor: artificial intelligence. 

The course, taught jointly with Harvard University and more often referred to by Harvard’s course code of “CS50,” will provide students with access to a “CS50 duck,” an AI-generated chatbot that can respond to student questions and offer hints to guide them toward an answer. 

“We started in spring 2023,” David Malan, a Harvard computer science professor who teaches CS50, told the News. “Among our goals ultimately is to approximate, through software, a one-to-one TA to student ratio so that students can ask all the more questions throughout the term, interactively so, as though they have their very own tutor by their side.”

Charlie Liu ’24, a head teaching assistant for the course, told the News that students have the option to chat with the web-based CS50 duck using a ChatGPT-like interface, or they can have their questions answered by the CS50 duck on the course’s Q&A platform. 

The AI-based technology will not reduce the need for human staff support, but Liu said that as a result of the AI’s around-the-clock availability, it will “amplify the impact of the teaching assistants that we do have.”

“By enabling students to ask the CS50 duck questions on a 24/7 basis, CS50’s AI tools allow our TAs to focus their time on in-person support for students who need and stand to benefit from it the most,” Liu wrote in an email to the News. 

The implementation of this tool comes amid an ongoing, university-wide discussion about how faculty and staff should address the growing popularity of AI-based tools such as ChatGPT — a machine learning tool that can generate code and answer questions. 

In contrast to ChatGPT, however, which Liu said can often be “too helpful,” the duck helps students while still allowing them to gain problem solving skills. 

“ChatGPT can be too helpful when answering questions, often giving full-blown answers that can detract from the learning process of solving a problem by oneself,” he said. “The CS50 duck, by contrast, provides helpful hints and guides students to an answer, similar to how a human TA would help students at office hours.”

The AI duck is inspired by the concept of “rubber duck debugging,” a method of debugging code in which the programmer attempts to find the bug by articulating their code line-by-line to a physical rubber duck. Through the process, if all goes well, the programmer can identify the bug by thinking out loud. 

The CS50 duck comes with a certain number of “hearts” that appear beside it on the screen. When a student asks a questions, the duck loses hearts; if the hearts run out, the student must wait for them to regenerate before asking more questions.

Charlie Calkins ’26, a student enrolled in CS50 this semester, said that he hopes the AI tool will be able to respond to questions written in “plain language.”

“I’m excited for the AI duck because it is specific to the class, meaning it will better understand my questions about course material,” he said. “A lot of times with online AIs, the bot misunderstands your question or gives you information outside the question’s scope.” 

Calkins also speculated that the technology’s addition to the course is designed as a way to prevent cheating. 

In 2017, the issue of cheating in the course was brought to light as the Harvard Crimson reported that more than 60 students enrolled in the course appeared before the college’s Honor Council for cases of academic dishonesty. 

However, the “regret clause” in the CS50 course policy allows students to self-report academic dishonesty in order to avoid larger consequences. 

Malan added that, in addition to developing the AI duck, the CS50 team has begun experimenting with AI-led training for human TAs. AI would train TAs “by simulating interactions with virtual students who are struggling with some topic.” 

This training, Malan said, may soon be able to help address topics in other fields, such as the humanities, arts and social sciences. 

Speaking more broadly on AI’s role in academia, Malan said that departments outside of Computer Science may soon be able to incorporate the technology into their own course instruction. 

“CS courses are perhaps advantageously positioned to be early adopters of AI, by nature of being able to write code themselves to incorporate it. But there will soon be all the more apps, all the more APIs, via which academia more generally will be able to leverage AI, either with less code or even no code.”

CS50 has been offered at Yale since Fall 2015.