Daylight in buildings is evaluated using the daylight factor DF [%], which is defined as the ratio of the light level inside a structure (Ei = illuminance due to daylight at a point on the indoors working plane) to the light level outside the structure (Eo = simultaneous outdoor illuminance on a horizontal plane from an unobstructed hemisphere of overcast sky). The illuminance values are calculated for the overcast winter sky with Eo=5000 lx. In the Czech republic (and many other European countries), the daylight factor in residential buildings is evaluated in two points in the room, located in the middle of the room’s depth and 1 m from the side walls on a horizontal working plane 0,85 m above the floor. The students of architecture are taught to calculate the daylight factor in the specific points of a room and to determine whether the values fit the legislative requirements. However, they have a hard time imagining what the room and its daylighting actually looks like. Therefore, a practical experimental simulation was performed. Various values of daylight factor were simulated and the participants were asked to perform several task in three different lighting conditions The goals of the experiment were: To demonstrate to the participants what the required daylight factor values actually look like, so that they are able to connect the abstract values to real rooms. To determine whether the architecture student perception of daylight inside of buildings corresponds with the reality. To verify whether the daylight factor values required by the legislative are sufficient for performing certain visually demanding task commonly done at home. The experiment is a part of a larger research project, which aims to improve the teaching of building physics (designing buildings with a good indoor environmental quality) in architecture universities.