An invention is something devised by human effort that did not exist before. Inventions are, by and large, either responses to specific needs or products of the inventor's wish to do something more quickly or efficiently. Inventions rarely appear out of the blue. Often, inventors will seek to adapt an older design, using a new material or configuration, to suit a slightly different need. Think of all the different types of cups there are: glass ones, paper ones, plastic ones, teacups with handles, "sippy" cups, thermal mugs, and on and on. Each of these was designed to meet a real or perceived need, shortcoming, or failure of other solutions.

More and more, want rather than need drives the process of invention. The boy inventor featured in this video segment wants a tool to reduce the amount of work he must do to collect and contain the tennis balls with which he and his brother play. He fashions his "tennis ball picker-upper" from an existing ball canister and strips of Velcro, which, when applied to the inside of the canister, provide enough friction to keep the collected balls from falling out. Leang attaches the modified canister to his racket handle, enabling him to collect balls without bending over. Though similar devices for collecting and holding tennis balls and golf balls already exist (called ball hoppers and shag bags, respectively), this young inventor has designed his "picker-upper" for his own needs, using materials available to him.

Though the video segment doesn't suggest he had any trouble with making his device, if he had, he would have tested it, isolated the problem, and tweaked the design until he got it right. During the design and development process, real-world inventors, product designers, and engineers typically develop initial models, called prototypes, which may be modified after being tested.