Anais do IHC'2001 - Departamento de Informática e Estatística - UFSC

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Anais do IHC’2001 - IV Workshop sobre Fatores Humanos em Sistemas Computacionais
1995] and to conjecture about visualizations that could be used in learnware for a specific
topic in Biology⎯Mendel’s laws of dominance. The result of this study is a set of
theoretical issues that, in the opinion of the authors, should be investigated in a long-term
research agenda about the use of DM in learnware interface design.
Direct Concept Manipulation for Learning about Geometry
Super Tangrams © (ST) is a piece of learnware that has been implemented using different
interface styles. ST is built around a puzzle-solving activity called tangrams. The concepts
to be learned in this activity are three geometrical transformations: slide (or translation),
turn (or rotation), and flip (or reflection). In ST, children solve tangrams puzzles by
manipulating on-screen images of given geometric shapes. Three distinct styles of
interaction ⎯ DOM (Direct Object Manipulation), DCM (Direct Concept Manipulation)
and RDCM (Reflective Direct Concept Manipulation) ⎯ have been polished to give
children an impression of a commercial game. This has been judged important to give
experiments a realistic atmosphere and to prevent implementation discontinuities from
interfering with the study.
In the DOM version, the user manipulates the geometric shapes directly. The desired
outline is presented in the center of the screen, with the available pieces scattered around
the periphery (see Figure 1). Buttons on the side allow the user to select flip (horizontally
or vertically), rotate (clockwise or counterclockwise), or drag mode. The order of the
puzzles is fixed and every puzzle has a fixed score, which is added to the users total score
when the puzzle is completed. This keeps the learning activity in close association with
game playing.
Figure 1: A snapshot of the DOM HCI style in ST
In the DCM version, the user directly manipulates visual representations of the
transformation concepts rather than the shapes themselves. The screen has a coarse grid in
the background and the idea of focussing on a piece (rather than on an operation) is
introduced (see Figure 2). The user chooses a shape (shown by the piece having a different
pattern), the operation (Slide, Turn, or Flip), and this causes the transformation
representation and the ghost image of the shape to appear. As indicated in Figure 2, when
Turn is selected the transformation representation is an arc attached to one vertex of the
focussed shape. The arc has a moveable center and endpoint. Manipulating the center