Using real-world data and visualization can be an engaging way for students in courses like data structures or algorithms to interact with the topics they are studying. The Map-based Educational Tools for Algorithm Learning (METAL) project provides a unique set of data and interactive algorithm visualization (AV) capabilities for this purpose. METAL’s graph data sets range in size from a few vertices and edges to several hundred thousand. Its data is derived from the Travel Mapping Project, and represents real highway and railway systems from around the world at a granularity convenient for visualization. METAL’s in-browser Highway Data Examiner (HDX) provides interactive code-level AV capabilities with debugger-like controls that can help students achieve a deeper understanding of graph and other algorithms more quickly. Students can also implement graph algorithms themselves in a programming language of their choice and display, in map form using HDX, the results of computations using those algorithms when applied to METAL data.

METAL data and AV cababilities have a low barrier to entry for instructors. Bringing this into a classroom can involve as little as following a link to a pre-configured AV so students can see an algorithm they are studying in action, or as much as adoption of several of METAL’s classroom-tested learning modules that can form more lengthy student exercises or assignments. METAL data and HDX are open source and freely available. The learning modules, with reference solutions, will be made available to interested instructors by request.