<P> The nine dots puzzle is much older than the slogan . It appears in Sam Loyd's 1914 Cyclopedia of Puzzles . In the 1951 compilation The Puzzle - Mine: Puzzles Collected from the Works of the Late Henry Ernest Dudeney, the puzzle is attributed to Dudeney himself . Sam Loyd's original formulation of the puzzle entitled it as "Christopher Columbus's egg puzzle ." This was an allusion to the story of Egg of Columbus . </P> <P> The puzzle proposed an intellectual challenge--to connect the dots by drawing four straight, continuous lines that pass through each of the nine dots, and never lifting the pencil from the paper . The conundrum is easily resolved, but only by drawing the lines outside the confines of the square area defined by the nine dots themselves . The phrase "thinking outside the box" is a restatement of the solution strategy . The puzzle only seems difficult because people commonly imagine a boundary around the edge of the dot array . The heart of the matter is the unspecified barrier that people typically perceive . </P> <P> Ironically, telling people to "think outside the box" does not help them think outside the box, at least not with the 9 - dot problem . This is due to the distinction between procedural knowledge (implicit or tacit knowledge) and declarative knowledge (book knowledge). For example, a non-verbal cue such as drawing a square outside the 9 dots does allow people to solve the 9 - dot problem better than average . </P> <P> The nine - dot problem is a well - defined problem . It has a clearly stated goal, and all necessary information to solve the problem is included (connect all of the dots using four straight lines). Furthermore, well - defined problems have a clear ending (you know when you have reached the solution). Although the solution is "outside the box" and not easy to see at first, once it has been found, it seems obvious . Other examples of well - defined problems are the Tower of Hanoi and the Rubik's Cube . </P>

Draw 3 straight lines to separate the dots