Educationalists experience difficulties with the construction of competence maps that describe final attainment levels of educational programs. Web-based support was developed with three supportive aids:A construction kit, a phenomenarium, and an information bank. Each supportive aid was expected to improve perceived process and product quality as well as learning. In a factorial experiment, 266 educational science students constructed a competence map, whether or not supported by each of the three supportive aids. The availability of the construction kit and the phenomenarium had positive effects on perceived process quality and learning. Furthermore, if there was no phenomenarium with example materials, the absence of the construction kit greatly diminished experienced support (i.e., one aspect of process quality); if a phenomenarium was present, the availability of the construction kit had relatively little effect on perceived support. In general, this study indicates that well-designed Web-based support helps to construct competence maps. The construction of a competence map is a difficult design process. The goal of the present study is to test if a Web-based support system may help designers to construct a competence map. In particular, the perceived effects of a construction kit, a phenomenarium, and an information bank on the quality of the construction process and the product of this process (i.e., the map) as well as on learning about the construction of competence maps were studied. In the Web-based support system, the construction kit consists of pre-fabricated parts and processes; the phenomenarium provides useful examples, and the information bank presents explicit information and guidelines.