[[abstract]]With the rapid development of Internet technology and Web-based education, distance learning provides a novel learning style, which is different from traditional education. In order to adapt different teaching strategies in accordance to individual students' abilities in a distance learning environment, system directed navigation of students was proposed in a distance learning standard called SCORM (sharable content object reference model). We introduce the distance-learning color Petri net (DCPN), applying the features of Petri nets, to decrease the complexity of the sequencing definition model in the SCORM 2004 specification. We thus construct a sequencing framework for various instructional strategies by piecing DPCN subnets ...