Lucy's research has focused on creating a mood classifier for text—a system that identifies the prevailing emotion conveyed by a given section of text as anger, happiness, sadness, etc. This required creating a computer learning system that could deal with sparse and noisy training data.

Following that, she has made significant progress in the particularly challenging task of detecting sarcasm.

In addition to her research, Lucy taught a summer course in robotics at Pomona for local high school students. While she received support from the CS department, she initiated and created the entire program independently.