When Yukihiro Matsumoto created the Ruby Language, he aimed to make a design mainly for the programmers to be productive and at the same time enjoy by following the principles of a good interface design. He believed that the system design must first consider the human being over what the computer needs.

The principle of the least surprise (POLS) is the principle that Ruby Language follows. “Matz” (Matsumotol’s Nick) was quoted saying that his primary design goal was to make a language that the programmer will be required minimize work and confusion. Actually, he hasn’t applied the principle olf the least surprise to the design of Ruby, but the phase is somewhat related with the Ruby On Rails Programming