Summary of the Thesis
Spatial ability is a component of intelligence, together with other abilities like verbal and numeric abilities, reasoning, memory, etc. This component (spatial ability) is of vital importance in the field of engineering, as it is considered fundamental for the typical engineering activities: design, planning and execution of all kinds of engineering products (Adánez and Velasco, 2002). 

As spatial skill can be taught, its development is an improvement to man’s spatial ability. In the last decade, spatial skill has become one of the main lines of work in the field of engineering, for obtaining new methodologies and tools to improve students’ spatial abilities.
 
This thesis develops totally practical educational materials based on graphic engineering. Tools have also been created to develop the spatial skills of engineering students, as well as to facilitate their learning of graphic projection systems, all through short training courses.

Mental tasks are analysed and measured with spatial tests and once these are defined, a set of exercises are collected, classified and selected in the following terms:
-	Exercises that are most frequently used in teaching Graphic Expression.
-	Exercises used in spatial skills training courses.
-	Exercises and theoretical explanations on the traditional dihedric system.

On the other hand, an analysis will be conducted of the effect of playing with a commercial video game, selected for its content in geometric components, so that the player must conduct mental spatial tasks, to develop his or her spatial skill. 

After creating the teaching material and developing computer tools, a range of training exercises have been undertaken with first year engineering and architecture students, to initially give the expected results concerning their improvement in spatial ability. Six training strategies have been used in this thesis:
-	Two courses using the Tetris video game (one on a PC platform and the other on a Nintendo DS platform)
-	Two courses using the dihedric projection system (one with master classes and the other with the support of a three-dimensional dynamic display to follow the explanations).
-	One course based on exercises that have been used for developing spatial skill and which have been adapted to an Augmented Reality based technology application.
-	One course based on the most widely used exercises in teaching Graphic Expression in first year university engineering courses in Spain.

With the data collected and the results obtained, we have been able to conduct a stringent study on the improvement achieved with each course. In some of the courses, we have also analysed the gender variable, the duration of the course and we have compared the improvement achieved by the students.
We have conducted a satisfaction and a usability study of the courses, in which students have the chance to state their opinions and preferences with regard to the courses and the usability of the computer tools developed.

The statistical analysis of the students show that all the courses or strategies are perfectly valid for improving their spatial ability, although it is true that some provide insight into graphic representation systems. What is at stake here is the students’ preference for training on one kind of course or another, with students being more inclined to choose the courses that offer them independent training and which are based on new technologies, electronic devices, internet, etc. 

These courses provide optimum training methods for developing the students’ spatial skills and some of them facilitate the learning of graphic projection systems.

Keywords: Spatial ability, spatial skill, engineering education, engineering graphics, augmented reality.