Hierarchical Dataflow Model: A Computation Model for School Children

A new computation model suitable for icon based programming languages is proposed. The model is used to design a programming language for school children on the Macintosh personal computer. The model consists of boxes and arrows forming a partially ordered set of nested boxes. Loops and Boolean data tokens are eliminated from the traditional dataflow model. Block structures and logical consistency (exception) are added. Using a formal definition of the model it is proved that the model is determinate