Epplets - Definition

Amruth N. Kumar

In a Parsons puzzle [1], the student is provided scrambled code and asked to reassemble the program based on a problem specification. Epplets extend Parsons Puzzles in the following ways:
  1. Students must assemble the program one statement at a time. In the original definition of Parsons Puzzle, students were asked to move "blocks" of code, the blocks having been pre-selected by the author of the problem. Moving one statement at a time is more challenging - it better elicits the underlying algorithm from the student.
  2. Students are provided feedback that helps them revise their incorrect program. In the original definition of Parsons Puzzle, choices were marked as incorrect. But, the authors "doubt that it is possible" to explain why. However, feedback is what helps students learn. Currently, epplets provide positional feedback, i.e., feedback on which lines should be moved up/down. They also explain why distracters are incorrect.
  3. In the original implementation of Parsons Puzzle, students were allowed 2-3 attempts to solve a problem. In epplets, students can take as many attempts as necessary, but cannot move on to the next problem until they have solved the current problem correctly. So, proficiency is not measured in terms of whether the answer is correct or not, but rather in terms of the number of events used by the student to solve a problem: the greater the number of events, the less likely that the student has mastered the material.
  4. In the original implementation of Parsons Puzzle, code was provided properly indented. Improperly indented code was provided as distracters. In Epplets, all code is provided without any indentation - to eliminate indentation cuing the correct answer. Students can indent the code once they have assembled it - attempts at indentation are not counted as problem-solving events.


  1. Parsons, D., and Haden, P., Parson's programming puzzles: a fun and effective learning tool for first programming courses, ACE '06: Proceedings of the 8th Australasian Conference on Computing Education - Volume 52 , Volume 52 Publisher: Australian Computer Society, Inc., January 2006