Parameterized code in computer programs (or visualizations or spreadsheets) is code where the arguments being operated on are defined once as a parameter, at the beginning, so they do not have to be repeatedly explicitly defined in the body of the code.  This allows for flexible and rapid updating of the input.  Its one drawback is in teaching a concept that relies on concrete numbers for maximum basic understanding.  For example, in teaching resampling methods I found that spelling out all the parameters in advance (e.g. the number of repetitions, or the sample size) made the code more complex and also made the part of the code that was “teaching” the resampling concept more abstract.  Computer scientists rebelled against this approach, feeling that best coding practices should be taught as well, not just the statistical concept.