There isn't a preference for one way over the other in-terms of a "best practice". Typically you see  " "  and ' '  used more often than %Q and %q because those can sometime lead to confusing code.  For a string that does not have substitution "" and '' are equivalent (in-terms of memory, runtime, etc). Usually, if you need substitution you use "", and if not, you use '', but it's personal preference.  We will quickly see that Ruby has 3 or more ways to do almost everything :)