Measuring Economic Graph Competence

The ability to work with graphs is at the core of the economic domain and is also one of the central challenges for novices in the field. To accurately assess the graph competence of higher education students, we developed and tested an 18-item graph competence instrument with different economics graphs. The sample consisted of 579 students from multiple higher education institutions in southwestern Germany. Item analysis based on item response theory revealed that the instrument addresses a wide range of ability levels and discriminates sufficiently between low- and high-ability learners. Concerning content validity, we find meaningful correlations between test scores and domain-specific knowledge and generic understanding of numerical quantities. Item difficulties indicate that questions that go beyond simple graph operations are challenging for learners.