Some of the learnings will be beyond skills.
Logical thinking: The outcomes of technical subjects are deterministic. That is, given a set of inputs and a sequence, the output doesn’t change. The student will learn to trust the laws that govern the subject. Outcomes aren’t magical (though they sometimes seem that way). One can wish for a different result in applying the same set of inputs in the same manner, but in the technical world (and for most subjects in the real world) one must change an input or the sequence of inputs to get a different result.
Persistence: Thomas Edison said “Genius is one per cent inspiration and ninety-nine per cent perspiration. Accordingly, a ‘genius’ is often merely a talented person who has done all of his or her homework.” The project is a substantial one. One that when completed, will give the doer a large sense of accomplishment. While it is ongoing though, there will be failures. The truth is, we humans don’t learn from success nearly as much as we learn from failure. When one picks himself up, dusts herself off, and finds a solution, there is success.
Self-fulfillment: When a person becomes capable in a field, that feeling of self-worth bridges over into other areas that the person is involved with. This is as true in technical fields, as it is in sports, in music and dance, and other areas. In grade school I knew a fairly homely, skinny kid, who had just moved into town. The first impressions of his peers–us, that is–weren’t good. They were reflected in the boy’s demeanor—shy, quiet, submissive to his classmates. But he became a champion runner in the space of a year or two. How our attitudes—and his outlook changed! Funny thing is: he didn’t even look homely to us anymore.
But skills are important too,
3D-Printing: Unless someone else is doing the 3D printing of the plastic parts—a friend or a technician at the library, there will be a lot of time spent with a 3D-printer. The maker will likely learn about the intricacies of calibrating the machine, about the settings to best slice the part into layers to get the best printed results, or how to get it going again after something goes wrong.
Post-processing: Depending on the age of the maker, he or she may or may not be ready for using hand-tools: knives, and portable drills, etc. But when ready, there’s a true joy in knowing your way around tools. I think that eighties slogan got it wrong. IMHO: it’s not “He who dies with the most toys wins.” It’s “He who dies knowing the most tools wins.”
Assembly: Assembling the Visible Robot isn’t really like assembling the trike that came under the Christmas tree. The robot is a precision machine, with some precision components. It’s also electronically controlled, so there’s a need to wire it up correctly. The documentation is complete, but attention-to-detail is important. The assembly portion of the project is where the maker can visibly see progress, minute-by-minute and hour-by-hour.
Electronics and Software: While the maker won’t become an electronic engineer or computer programmer as a result of completing the project, he or she will get at least a taste of both: e.g., how a computer communicates to the robot controller; how firmware is used and setup; how a stepper motor works; how one is controlled.
Design: If today’s maker enjoys creating new things, he or she might veer off into mechanical design, electronics, or programming—or maybe into all three. A new word has some into the language describing just this: it’s “mechatronics.” As the word infers, it refers to working across the boundaries. It perfectly describes working in the field of robotics. One of the wonders of this new world we live in is that many of the software tools used to work in these fields are free for the download: OpenSCAD is a 3D computer-aided-design (CAD) tool the the Visible Robot was designed with; gEDA is a set of tools for electronic design; Arduino and GCC are tools for software development.
In particular, for 3D mechanical design I’m a fan of OpenSCAD. While I’m no expert in the field, I consider it an ideal first programming language. (Although the techies would properly call it a modeling language). This, because as you write a program describing some geometric shape, that shape appears in front of you. It gives immediate visual feedback. Deride it as instant gratification if you like, but it beats carrying all that logic around in your head!
For hacking—meaning improving, extending, making something do things the original designer never thought of—electronics, I like the Arduino. It too gives good feedback. Light up an LED, move a motor, display the input from a sensor. All from a fairly easy-to-learn language.
Community: Join a group of developers doing something interesting. Grow with the project.
Invent!: Truly, the 21st century will belong to the skilled and the creative. Developing useful skills allows the creative side of a person to come to the forefront.