Adaptation of the Mental Cutting Test for Use among the Blind or Visually-impaired

This paper seeks to illustrate the first steps in a process of adapting an existing, valid, and reliable spatial ability instrument – the Mental Cutting Test (MCT) – to assess spatial ability among blind and low vision (BLV) populations. To adapt the instrument, the team is developing three-dimensional (3-D) models of existing MCT questions such that a BLV population may perceive the test tactilely with their hands.

Each TMCT question is created by modeling and 3-D printing the objects represented by two-dimensional pictorial drawings on the MCT. The 3-D models of 25 items of the MCT are created using a solid modeling process followed by an additive 3-D printing process. The correct answer to each MCT question is the section view defined by a plane-of-interest (POI) intersecting the figure in question. A thin plane extending from the figure identifies the POI of each problem. The possible answers were originally presented in multiple representations including 3-D printed extrusions on top of a thin plate, and two forms of tactile graphics. The 3-D printed answers are developed by a combination of acquiring accurate dimensions of the 3-D figure’s cross-section and scaling up the printed paper test.