A new Internet tool for automatic evaluation in Control Systems and Programming

Abstract

In this paper we present a web-based innovative education tool designed for automating the collection, evaluation and error detection in practical exercises assigned to computer programming and control engineering students. By using a student/instructor code-fusion architecture, the conceptual limits of multiple-choice tests are overcome by far. The proposed system is also able to individually parameterize the exercises for each student and allows an instructor to implement innovative self-learning techniques in which student can obtain a measure of their knowledge continuously along the whole course length. The proposed automatic evaluation system has been applied to several control engineering courses at the University of Seville and the results several case studies are presented here.

Introduction

The quick expansion of the Internet as a community collaborative tool in all sectors started in the nineties and has now reached maturity. The uses of today’s XHTML pages little has to do with the initial, mostly static, contents of that period. Recently, the term Web 2.0 has been coined in order to denote a second generation of the Net, based on user communities which are responsible for providing most part of the content. Team collaboration, file sharing, blogging, product user ratings and forums are popular tools, implemented in content management systems such as Drupal and Joomla. Worldwide education institutions have started using packages such as Moodle and WebCT, that offer all these collaborative tools, plus some additional features, at the service of education. The use of this technological framework in education reduces the student mobility requirements (restraining expenses in education institutions and companies) and enables a closer interaction between teacher and students (using different tools such as forums, e-mail, FAQ, immediate course material delivery, warnings, grades, planning, calendars, etc…). In Kapur and Stillman, 1997, Poindexter and Heck, 1999, Heck et al., 2000, an overview of the possibilities offered to educators is presented.

In control systems education there has been great interest in web platforms that enable the users to interact with a remote laboratory system, either real (see Cedazo et al., 2007, Casini et al., 2003, Casini et al., 2004) or simulated (Maussion and Tricot, 2008, Sanchez et al., 2004, Sanchez et al., 2006, Torres et al., 2006), extending to the web the crucial aspect of practical educational work in engineering.

However, learning management systems, though very effective in distributing material and collecting the student assignments, offer limited evaluation capabilities, in general reduced to multiple-choice questions (MCQs). The use of MCQs in Engineering is widespread Petridis et al., 2003, Tartaglia and Tresso, 2002 and its convenience is currently under discussion Gentil and Exel (2004). From our perspective, more sophisticated tools specific for evaluating elaborate projects from students are highly desirable. Little effort has been made in order to automatically grade complex assignments while some interesting examples in diverse fields are Jiang et al., 2009, Jaaskelainen et al., 2009, Gerosa and Narayanan, 2008, Chiou et al., 2009.

On Computer Science, a number of approaches have been developed whose characteristics include automatic evaluation, see for example Douce et al., 2005, Gutiérrez et al., 2010. In Control Engineering, student assignments likely to be automatically graded range from mathematical problems (e.g. eigenvalue problems, state-space matrix analysis), controller parameter tuning, simulation-based work, and algorithm programming exercises. Among the few virtual laboratories that offer automatic evaluation for programming courses we find Rodriguez, Zamorano et al., 2007, Rodriguez, Pedraza, Garcia et al., 2007, Rodriguez, Pedraza, Dopico et al., 2007, Garcia et al., 2009, however, they provide particular solutions that cannot be used in other applications.

Motivated by the above discussion, we have developed a fully novel virtual education platform designed for automating the collection, evaluation and error detection in practical exercises assigned to control engineering students that allows to introduce user (instructor) defined code in some computer language (nowadays Matlab and C language are implemented), to algorithmically evaluate the student’s solution. This opens the possibility of functional evaluation of complex engineering designs, such as computer algorithms, controller tuning, control system design analysis exercises and much more. In mathematics there are several web-based systems based on using computer algebra system (CAS) with the internet delivery to provide a sophisticated mechanism with which to grade students’ work Klai et al., 2000, Sangwin, 2004, Mavrikis and Maciocia, 2003, albeit do not address the requirements of programming and in general are aimed at designing online courses based on a sequence of short, concise questions whose solution is a function that has to be defined using the appropriate syntax. The platform presented in this paper allows for more complex mathematical (and engineering) exercises in which the student solution is not a single function and moreover, the problem may be personalized for each student beyond a simple randomization. In addition, it allows the implementation not only of traditional assessment, but also dynamic assessment, see for example Wang (2010), based teaching methodologies in engineering courses with a large number of students. In the sequel we will describe the new evaluation tool and analyze a particular experience carried out in a control systems design course at the University of Seville. Many exercises in this field have a common algorithmic structure and a set of numerical specifications that can be automatically verified using our approach.