Hillier has been involved with the Institute of Physics throughout her career. In particular, she has concentrated on gender and diversity within the physics community. Hillier has been responsible for the evaluation of the Conference for Undergraduate Women in Physics (CUWiP) since it launched in the United Kingdom in 2015.[8] She found that women felt a stronger sense of belonging to the physics community after attending the conference.[7] Her evaluation is used to inform the design of future conferences, and ensured that the conference remains a key date in UK physics' calendar.[7] To identify obstacles and solutions to gender imbalances within the scientific community, Hillier has studied the experiences of successful women scientists.
Bryant, Peter; Nunes, Terezinha; Hillier, Judith; Gilroy, Claire; Barros, Rossana (4 December 2013). "The Importance of being able to deal with variables in learning science". International Journal of Science and Mathematics Education. 13 (S1): 145–163. doi:10.1007/s10763-013-9469-x. ISSN1571-0068. S2CID145233104.