The ability to visualise objects and situations in one's mind, and to manipulate those images, is a cognitive skill vital to many career fields, especially those requiring work with graphical images. Spatial abilities have been widely studied and are known to be fundamental to higher-level thinking, reasoning and creative processes. Unfortunately, of all cognitive processes that have been investigated, spatial cognition shows some of the most robust gender differences favouring males, especially in the ability to mentally rotate three-dimensional (3D) objects. This has obvious implications for our attempts to encourage gender equity in technical and scientific fields. Recognising the importance of well-developed spatial skills for technological careers, the National Council of Teachers of Mathematics (NCTM) in the US has included benchmarks regarding the development of spatial abilities within the Precollege Mathematics Educational Standards (NCTM, 2000), and middle-school mathematics education has been a focus of national interest due mainly to the results of the Third International Mathematics and Science Study and state, national and local standards (Ai, 2002). Fortunately, although individuals vary in spatial performance, research has shown that most, if not all, of the component skills can be improved through training and practice.
2 PRIOR RESEARCH IN SPATIAL COGNITION
According to Piaget (Bishop, 1978), spatial skills are developed in three stages. In the first stage, topological skills are acquired. Topological skills are primarily two-dimensional (2D) and are acquired by most children by the age of 3-5. With these skills, children are able to recognise an object's closeness to others, its order in a group, and its isolation or enclosure by a larger environment. The second stage involves visualising 3D objects and perceiving what they will look like from different viewpoints, or what they would look like if they were rotated or transformed in space. Most children have typically acquired this skill by adolescence, however, if the object is unfamiliar, many students in high school or even college have difficulty visualising at this stage of development. In the third stage, people are able to visualise the concepts of area, volume and distance in combination with those of translation, rotation and reflection. At this stage, therefore, a person is able to combine measurement concepts with their previously acquired projective skills.
By one estimate, there are at least 84 different careers for which spatial skills play an important role (Smith, 1964). For technical professions, such as engineering, spatial visualisation skills and mental rotation abilities are especially important (Maier, 1994). Norman (1994) found that a person's spatial skill level was the most significant predictor of success in his/her ability to interact with and take advantage of the computer interface in performing database manipulations, and Sorby (2000) found that a person's spatial skills are related to his/her ability to effectively learn to use computer aided design software. Eyal & Tendick (2001) found that a person's spatial ability is related to his/her ability to effectively learn how to learn to use the modern-day laparoscopic equipment used throughout the medical profession. Tartre (1990) has suggested gender differences in spatial skills may be linked to math performance and, indeed, when mental rotation ability was held constant in one study, gender differences in mathematical problem solving disappeared (Casey et al, 1992).
A significant body of work in the chemical sciences was undertaken by Bodner and his co-workers in the late 1980s (Pribyl & Bodner, 1987; Carter et al, 1987; Bodner & McMillan, 1986). In those studies, it was noted that both spatial ability and gender can play a significant role in the success of students, particularly in entry-level classes such as General Chemistry. …