Lijuan Cao’s research while affiliated with University of North Carolina at Charlotte and other places

We have established a research-practice partnership (RPP) to establish a computer science (CS) and computational thinking (CT)-focused STEM ecosystem at two middle schools. The STEM ecosystem model is used as a framework to address systemic barriers to student participation in computing. Creating a school-based CT/CS-focused STEM ecosystem through an RPP approach entails involving all stakeholders in the research process. Borrowing upon visual participatory research methods, we developed a graphic research instrument to engage practitioners in the research process and to elicit their perspectives on strategies for building the school ecosystem. This paper describes our research process and reports on the results of a pilot study with practitioner-members of our RPP team. Our contribution to the research base is a potential instrument for other university-based teams who are members of RPPs and looking for more productive and equitable ways to engage practitioners in the research process.

The flipped classroom pedagogy is a popular framework for teaching computing courses. This pedagogy hinges on students completing the preparatory (prep) work before class. This usually requires watching videos or reading several sections from the textbook. To encourage students to do the prep work, a short multiple-choice online quiz is often given. However, despite this incentive, many students do not spend enough time on the prep work. To deal with this challenge, we introduce a new approach that is designed to be more engaging. This approach replaces the regular textbook with an interactive textbook and replaces the multiple-choice quizzes with small programming assignments, which are graded automatically to give students immediate feedback. To test the efficacy of this approach, we offered two sections of the course with the only difference being in the prep work, one (the experimental group) used the proposed approach while the other (the control group) used a standard approach. Our results suggest that students in the experimental group tended to perform better in terms of both the overall mean and the DFW rate, i.e. the proportion of students receiving a D, F, or W (withdraw) as their overall grade in the class. Further, students in the experimental group tended to report more positive attitudes to the prep work and the class overall.

It has been long established that discrete structures is an important and foundational component of the computer science curriculum. However, the topics covered in this course tend to be more abstract than those covered in most other introductory computer science courses. This leads to additional challenges for instructors and students. To deal with these challenges, we introduce a new pedagogy for teaching this course. Our approach is based on a variant of the flipped classroom paradigm and is comprised of four main components: before class preparatory work, in-class mini lecture, in-class team based problem solving activities, and weekly individual assignments. In this paper, we discuss these components in detail. Our approach is informed by several cutting-edge teaching methodologies including active learning, light weight teams, and gamification. We conclude the paper by discussing the results of a survey taken by the students and a summary of the grades attained in the class. These show that our approach was well received by the students and has led to good learning outcomes.

We propose a new methodology for testing whether two writing samples were written by the same author. While many such tests are based on an index of lexical richness, we propose to use an entire profile of such indices. Specifically, we evaluate a profile of generalized Simpson’s indices for two writing samples and see if the profiles are significantly different or not. We validate our methodology on several poems whose authorship is known. We then apply it to test whether the poem ‘Shall I Die?’ which is sometimes attributed to William Shakespeare was, in fact, written by him. Further, we provide R code and a package for R that easily implements this methodology.