Section: Research Program
The scientific approach that we follow considers user interfaces as means, not an end: our focus is not on interfaces, but on interaction considered as a phenomenon between a person and a computing system  . We observe this phenomenon in order to understand it, i.e. describe it and possibly explain it, and we look for ways to significantly improve it. HCI borrows its methods from various disciplines, including Computer Science, Psychology, Ethnography and Design. Participatory design methods can help determine users' problems and needs and generate new ideas, for example  . Rapid and iterative prototyping techniques allow to decide between alternative solutions  . Controlled studies based on experimental or quasi-experimental designs can then be used to evaluate the chosen solutions  . One of the main difficulties of HCI research is the doubly changing nature of the studied phenomenon: people can both adapt to the system and at the same time adapt it for their own specific purposes  . As these purposes are usually difficult to anticipate, we regularly create new versions of the systems we develop to take into account new theoretical and empirical knowledge. We also seek to integrate this knowledge in theoretical frameworks and software tools to disseminate it.