This paper presents an experiment designed to study firms' behavior and market dynamics, when information about the market structure and opponents' actions is difficult to acquire and process. Our experimental software controls the information acquisition process of the subjects. Paying attention not only to what players do, but also to what they know, it is possible to better understand the cognitive processes guiding their choices and, consequently, the impact of the informational structure on their behavior. According to our results, Best-Response Dynamics is the main component of subjects' learning process. We also find that, when subjects look at the strategies individually adopted by their competitors, they tend to imitate the most successful behavior, which drives the market towards a more competitive outcome.