Two experiments were carried out to study the effect of the sequencing of the information in an instructional program. In both experiments, two different ordering principles were used. These principles were based on the relation between the to be learned concepts. The ordering of the information could be successive or simultaneous. The relationship between concepts is categorized either successive or coordinate. It was hypothesized that a simultaneous presentation would show better learning results than a successive presentation if between the to-be-learned concepts exists a co-ordinate relationship. A successive presentation would lead to better results in case of a successive relationship. Results suggest that the definition of both types of relationships needs refinement. Further the results show that for coordinate related concepts a simultaneous presentation is preferable.