Robotics is an interdisciplinary subject, combining different fields of study that in traditional educational systems you usually examine separately: physics, mathematics, electronics, and computer programming, just to name a few. Robotics is a hobby through which you can Þnd a practical application for many of the concepts you studied in schoolÑor, if you didnÕt study them, or donÕt have an aptitude for them, it offers a great way to learn by experience and by having some fun.The most important point, however, is that robotics is more than the sum of the basic notions youÕre required to know. It gives you a precise and concrete idea of how these notions integrate and complete each other. So it happens that when youÕre looking for a solution to a problem, by following your intuition and knowledge itÕs almost a given that youÕll Þnd a solution different from that devised by someone else. LetÕs say you have just built your Þrst line-following robot (weÕll discuss this topic in detail in Part II).You discover that your robot works, but it makes too many corrections to its steering and this affects its resulting speed.What could you do to Þx it? If you have a talent for mechanics, your Þrst approach might be to try and modify the structure and architecture of your robot.You might observe that the wheels are too close to each other in your differential drive, and for this reason your robot turns very fast and tends to over-correct its steering. Or you might decide that the differential drive architecture after all is not the best option for line following.You may even discover that the position of the light sensor in the robot greatly affects its performance.