Several hypermedia environments have been developed in the last years with the intention of promoting the acquisition of knowledge on a wide range of topic and developing problem-solving abilities. However, there are many different and sometimes conflicting claims about the capability of these environments to promote meaningful learning. We have developed a hypermedia learning environment with a tutorial component that exploits Artificial Intelligence techniques. This hypermedia, called Logiocando, targets a special category of users, namely children of the fourth level of primary school (9-10 years old), to teach them basic concepts of logic. Two empirical evaluations of the educational impact of Logiocando have been performed. Such experiments compared two teaching approaches: the computer-based one that relies on the hypermedia system, and the traditional one that relies on classroom instruction. The studies involved a large sample of pupils of primary school. Results showed that Logiocando can certainly be considered a valid support in the process of learning and deepening logic knowledge, provided that children are adequately motivated.