Introduction

Web maps have reached the level of depth and breadth that some academic generalization becomes practical. This paper outlines four design patterns of Web maps. These patterns are based on a task oriented grouping of Web maps and a design pattern framework developed in distributed processing. Web maps are grouped into index, guide, narrative, and answer, with four corresponding design patterns: 2D indexing, Dynamic spanning tree & visual association, thematic mapper, and single page query builder. Each pattern is described following a template that includes the following elements: name, intent, primal forces, applicability, solution, benefits, and example.