An invention is something devised by human effort that didn't 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. Inventors will often 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 so on. Each of these was designed to meet a real or perceived need, shortcoming, or failure of the cups that came before it. And keep in mind that none of these cups has replaced the others; they merely continue to live side by side in cupboards everywhere.

At least in industrialized countries, it is more frequently want than need that drives the process of invention. Lauren, the girl inventor featured in this video segment, wants to make her lacrosse stick easier to transport to and from practice. The standard lacrosse stick is too long to fit into her backpack, and it is difficult to carry in her hand while she's riding her bike.

One solution to Lauren's problem would be to simply cut off and discard a long section of the stick, making it shorter and easier to carry. If she did this, though, she would lose much of the lacrosse stick's intended functionality. A long stick provides the lacrosse player with the reach and leverage necessary to catch and throw the lacrosse ball. Lauren's design must therefore allow her to temporarily shorten the stick for transport and then reassemble it for play.

Though the video segment doesn't show Lauren's engineering design process, she probably spent a lot of time thinking about and discussing her idea with others. Before she made the first cut in her lacrosse stick, she probably had a very clear idea in mind, and possibly on paper, as to how she would reassemble the pieces. Real-world inventors, product designers, and engineers typically go even further than just visualizing and drawing their plans and ideas; they develop initial models called prototypes that inform decisions about how the product will ultimately look and function.