SI Seminar by Joey Bevilacqua
Talk: Assessing the Understanding of Expressions: A Qualitative Study of Notional-Machine-Based Exam Questions
USI, Lugano, Switzerland
Thu, May 16, 2024
Joey Bevilacqua presenting “Assessing the Understanding of Expressions: A Qualitative Study of Notional-Machine-Based Exam Questions” at the USI Software Institute.
Abstract
Notional machines are pedagogical devices that assist the understanding of some aspect of programs or programming. We present a qualitative study of the use of a notional machine - ‘expression as tree’ - as an instrument to assess the student’s understanding of expressions. We collect and analyze a corpus of 542 hand-drawn expression tree diagrams from 12 different exams in 6 university programming courses over the course of 4 years. We devise and use a tailored coding approach that admits a wide variety of mistakes, due to the theoretically well-defined programming language constructs that underpin the notional machine. Our results show that even a single question based on the notional machine is able to provide valuable insights into student’s understanding of several key aspects of programming.