Based on studies carried out on qualitative data an instrument was constructed for investigating how larger numbers of students handle graphics. This test, consisting of 18 pages, each with its own graphic display(s) and a set of tasks, was distributed to 363 students, 15–16 years of age, from five different schools. The format of the questions varied, as did the format of the graphics. As students' performance was expected to be multidimensional, confirmatory factor analysis was carried out with a structural equation modeling technique. In addition to the identification of a general graphicacy-test factor (Gen) and an end-of-test effect (End′), a narrative dimension (Narr′) was vaguely indicated. This model was then related to a six-factor model of students' formal academic achievement measured by their leaving certificates from compulsory education. The strongest correlation obtained was between the general graphicacy-test dimension (Gen) and a mathematic/science factor (MathSc′) in the grades model. In addition, substantial relationships were detected between the Gen factor and both an overall school achievement factor (SchAch) and a language factor (Lang′) in the grades model. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 43: 43–62, 2006