Doris Zahner

A fix for fixation? rerepresenting and abstracting as creative processes in the design of information systems

Abstract Fixation prevents the associations that are bridges to new designs. The inability to see alternative solutions, or even to see how to map known solutions onto current problems, is a particularly acute problem in the design of software-intensive systems. Here, we explored two related ways of liberating fixated thinking: abstracting and rerepresenting. Although both techniques helped designers generate original ideas, not all the added ideas fit the problem constraints. We discuss ways the results might be used to generate reflective design aids that help designers to first generate original ideas and later prune them.

Methodological challenges in international comparative post-secondary assessment programs: lessons learned and the road ahead

The assessment of student learning outcomes in the tertiary school sector has seen an increase in global popularity in recent years. Measurement instruments that target higher order skills are on the rise, whereas assessments that foster the recall of factual knowledge are declining. The Assessment of Higher Education Learning Outcomes (AHELO) project was designed with the goal of developing a cross-national concept for valid assessment of generic and domain-specific student learning outcomes on an international comparative basis. AHELO and other international comparative assessment systems face numerous methodological challenges that pertain to test design and development, translation, adaptation, student sampling, scoring, reporting, and the validity of score interpretations. The goal of this paper is to generate ideas for the improvement of cross-national research agendas, such as the AHELO project. The main purpose is to focus on the lessons learned from the AHELO feasibility study and other international assessment studies that help inform the research of future multinational educational assessment studies.

Cognitive Tools Shape Thought: Diagrams in Design

Thinking often entails interacting with cognitive tools. In many cases, notably design, the predominant tool is the page. The page allows externalizing, organizing, and reorganizing thought. Yet, the page has its own properties that by expressing thought affect it: path, proximity, place, and permanence. The effects of these properties were evident in designs of information systems created by students Paths were interpreted as routes through components. Proximity was used to group subsystems. Horizontal position on the page was used to express temporal sequence and vertical position to reflect real-world spatial position. The permanence of designs on the page guided but also constrained generation of alternative designs. Cognitive tools both reflect and affect thought.

Diagrams as Tools in the Design of Information Systems

Design typically relies on diagrams to offload memory and information processing and to promote discovery and inferences. Design of information systems, in con-trast to design of buildings and products, depends on topological connectivity rather than Euclidean distance. Understanding graph topology and manipulating graphs are essential skills in the design of information systems, because graph manipulation facilitates the refinement of designs and the generation of alternative designs. Here, we found that students of systems design have difficulties interpret-ing diagrams, revealing two biases, a sequential bias and a reading order bias. The results have implications for teaching as well as diagram design.

Alteration in systemic vascular resistance and cardiac output during acute cellular rejection and recovery in heart transplant recipients.

Coronary vascular reserve is impaired during acute cellular rejection of the orthotopically transplanted heart, but changes in the peripheral vasculature during rejection have not been well described. To investigate whether peripheral vascular compensatory mechanisms are preserved after orthotopic heart transplantation (OHT), we longitudinally observed systemic vascular resistance (SVR) and cardiac output (CO) during acute cellular rejection. CO decreased during high-grade acute cellular rejection, and maintenance of mean arterial pressure was achieved by increases in SVR, and these changes did not return to baseline until several months after histologic resolution of rejection.

Transforming Descriptions and Diagrams to Sketches in Information System Design

Sketching is integral to information systems design. Designers need to become fluent in translating verbal descriptions of systems to a variety of kinds of sketches, notably sequential and logical, and to translate among the kinds. Here, we investigated these cognitive skills in design students, asking them to design a system configuration starting from either a sequential diagram or a sequential description. Although the two source descriptions were logically equivalent, the diagram led to designs that corresponded more closely to the source description --- that is, designs with fewer omissions of crucial components and links. Text descriptions led to more variable and less accurate designs, most likely because they require more cognitive steps from problem representation to problem solution.

Diagrams Affect Choice of Strategy in Probability Problem Solving

We investigated whether diagrams influence strategy choice and success in solving elementary combinatorics problems. Generic diagrams (trees or two-way tables) were provided to solvers as aids. Participants’ coded solution strategies revealed that problem solvers tended to utilize mathematical structures and solutions that easily mapped to the diagrams’ visuospatial relations. For example, when provided with an unlabeled N-by-N table, solvers tended to proceed by defining an equally-likely outcome space (an “outcome-search” solution); when provided with a binary tree, solvers tended to adopt a “sequential” solution defining stage-wise simple or conditional probabilities; when provided with an N-ary tree cuing equally-likely outcomes, choices were split between the two solution types. Furthermore, the tree and the table showed different patterns of characteristic errors, and perhaps for this reason, the tree led to higher accuracy for one problem that involved sequential sampling without replacement, while the table was best for the other problem, involving independent events. The results support arguments that the content and structure of diagrams must be congruent to that of the problem at hand and be easily and accurately perceived to be effective, and demonstrate that diagrams can influence strategy choice in problem solving.