GEOCHEMICAL CHARACTERIZATION OF LOWER TOARCIAN SOURCE ROCKS FROM NW GERMANY: INTERPRETATION OF AROMATIC AND SATURATED HYDROCARBONS IN RELATION TO DEPOSITIONAL ENVIRONMENT AND MATURATION EFFECTS

This paper reports the results of a study that compared two concept-mapping techniques, one high-directed, "fill-in-the-map," and one low-directed, ^construct-a-map-from-scratch." We examined whether: (1) skeleton map scores were sensitive to the sample of nodes or linking lines to be filled in; (2) the two types of skeleton maps were equivalent; and (3) the two mapping techniques provided similar information about studentsʹ connected understanding. Results indicated that fill-in-the-map scores were not sensitive to the sample of concepts or linking lines to be filled in. Nevertheless, the fill-in-the-nodes and fillin-the-lines techniques were not equivalent forms of fill-in-the-map. Finally, high-directed and low-directed maps led to different interpretations about studentsʹ knowledge structure. Whereas scores obtained under the high-directed technique indicated that studentsʹ performance was close to the maximum possible, the scores obtained with the low-directed technique revealed that studentsʹ knowledge was incomplete compared to a criterion map. We concluded that the construct-a-map technique better reflected differences among studentsʹ knowledge structure.