Piled Higher and Deeper (also known as PhD Comics)[1] is a discontinued newspaper and webcomic strip produced from 1997 to 2018.

First published in 1997 when Cham was a grad student himself at Stanford University, the strip deals with issues of life in graduate school, including the difficulties of scientific research, the perils of procrastination, and the complex student–supervisor relationship.

Cham continued the strip while completing his PhD and later while an instructor in mechanical engineering at Caltech, then in July 2005 left this work to become a full-time cartoonist.

The strip was also syndicated free to student newspapers, with Cham earning a living through book sales, merchandise, and giving lectures.

[4] Piled Higher and Deeper introduced its main characters early in its run, and their personalities have remained fairly constant during the strip's several years of publication.

[citation needed] In the strip's first few seasons, the characters were clearly Stanford University students, though the number of school-specific references and jokes has decreased since.

[citation needed] Cham has said that while the characters are not based on real people, he was inspired by colleagues, classmates, and his brother's friends.

Upon several occasions, the strip has included spoofs of popular movies, like The Thesis (The Matrix),[# 57] Raiders of the Lost Dissertation (Raiders of the Lost Ark),[# 58] I, Grad Student (a mixture of the book and movie I, Robot),[# 59] and Summer days ("Summer Nights"[# 60]).

Cham has also released two song parodies, purportedly sung by Tajel, in MP3 format: "Closer to fine"[# 63] (cf.

[10] It was released in September 2015; the comedy relates to a research team seeking a key molecule in a cutthroat environment for jobs and grants.

A 2009 article wrote that "the popularity of his keynote lectures... are enough to make even the most distinguished professor green with envy."