Ada Lovelace and Lillian Gilbreth are important in interaction design history because they both made early contributions that influence how we think about technology and human interaction.

As Ada Lovelace is ‘the first computer programmer’, and she wrote the first algorithm intended to be carried out by a machine, she foresaw the potential of computers beyond calculations. On the other side, Lillian Gilbreth is a pioneer in industrial and organizational psychology. She work on time-and-motion studie, focused on improving efficiency in workplaces. They both ahead of their time in thinking about how people interact with machines and systems.