This tutor consists of a Student Workbook and a series of web-based explanatory Foundation Topics that directly support the workbook. It includes a further series of Supplementary Topics that expand the scope of the foundation work. The purpose of this tutor is to provide support to the student's Mentor, be that person teacher or parent. A Mentor prepared to work through this tutor will acquire the Logo background and programming skills necessary to assist a student to use Logo to solve problems they have posed for themselves.

A guided discovery approach is proposed with the Mentor acting as an informed resource and intervening at critical moments in the students' use of Logo to solve those problems. The tutor is typified by the almost complete absence of mentor-provided procedures in the early stages of discovery. The Mentor's role is to gradually enlarge student command of the innate turtle language (the Logo primitives) and basic programming principles. Students are empowered by their growing ability to use this innate language to generate a turtle language of their own.

Many teaching texts take a very structured approach to the use of Logo, contrary to the dream that Seymour Papert had for it in his seminal work, Mindstorms (1980). Complete student freedom to explore Logo, an approach at the other extreme, is an equally mistaken view of Papert's intent. Neither approach is likely to realize the power that Logo has to shape and develop student thinking. The guided discovery approach, suggested by this tutor, gives students considerable freedom to propose and solve problems for themselves but, at the same time, it enhances their power to use that freedom by ensuring that certain fundamental aspects of Logo are not overlooked nor developed haphazardly.

I must first declare my presumptions about children upon which I base my approach.
These are:

• they work best if they feel they have ownership of the problem;
• they have the broader concepts and ideas to develop significant pieces of work, and the motivation and stamina to do so;
• they can only retain ownership of the problem if they have the basic fundamental skills needed to accomplish the task they have set themselves, and if their Mentor is ready to furnish help and guidance at critical moments and at a level suited to their current level of development.

I see the fundamental aspects of skill development as being:

• the early introduction of variables;
• the awareness of, and the ability to use, the Total-trip Theorem and its corollary, the Reverse-path Principle (as you will see later these are grand labels for quite simple concepts);
• the development of good style by requiring a procedure layout that heightens student perception of similarities and patterns and facilitates the cloning of procedures in the editor;
• the development of good style by the appropriate naming of procedures, variables, and files; and
• an emphasis on a modular approach to problem solving.

Gradually, students' ability to propose problems using Logo will outstrip their ability to write procedures to solve them but not their ability to use and adapt more complex procedures to suit their own purposes. A Mentor who has ensured their students have developed the fundamental Logo skills will be able to identify such moments and be able to provide the necessary 'technical' assistance without assuming ownership of the problem.