There is increasing interest in the use of serious games in STEM education. Interactive simulations and serious games can be used by students to explore systems where it would be impractical or unethical to perform real world studies or experiments. Simulations also have the capacity to reveal the internal workings of systems where these details are hidden in the real world. However, there is still much to be investigated about the best methods for using these games in the classroom so as to derive the maximum educational benefit. We report on an experiment to compare two different methods of using a serious game for teaching a complex concept in marine ecology, in a university setting: expert demonstration versus exploration-based learning. We created an online game based upon a mathematical simulation of fishery management, modelling how fish populations grow and shrink in the presence of stock removal through fishing. The player takes on the role of a fishery manager, who must set annual catch quotas, making these as high as possible to maximise profit, without exceeding sustainable limits and causing the stock to collapse. There are two versions of the game. The “white-box” or “teaching” game gives the player full information about all model parameters and actual levels of stock in the ocean, something which is impossible to measure in reality. The “black-box” or “testing” game displays only the limited information that is available to fishery managers in the real world, and is used to test the player's understanding of how to use that information to solve the problem of estimating the optimal catch quota. Our study addresses the question of whether students are likely to learn better by freely exploring the teaching game themselves, or by viewing a demonstration of the game being played expertly by the lecturer. We conducted an experiment with two groups of students, one using free, self-directed exploration and the other viewing an expert demonstration. Both groups were then assessed using the black box testing game, and completed a questionnaire. Our results show a statistically significant benefit for expert demonstration over free exploration. Qualitative analysis of the responses to the questionnaire demonstrates that students saw benefits to both teaching approaches, and many would have preferred a combination of expert demonstration with exploration of the game. The research was carried out among a mix of undergraduate and taught postgraduate science students. Future research challenges include extending the current study to larger cohorts and exploring the potential effectiveness of serious games and interactive simulation-based teaching methods in a range of STEM subjects in both university and school settings.

The three main assertion-based verification approaches are: design by contract (DBC), extended static checking (ESC) and verified design by contract (VDBC). Each approach offers a different balance between rigour and ease of use making them appropriate in different situations. Our goal is to explore the use of these approaches together in a flexible way, enabling an application to be broken down into sections with different reliability requirements and different verification approaches used in each section. We explain the benefits of using the approaches together, present a set of guidelines to avoid potential conflicts and give an overview of how the Omnibus IDE provides support for the full range of assertion-based verification approaches within a single tool.

This issue of Formal Aspects of Computing contains nine papers, all related to the formal specification and the analysis of the ‘Tree Identify’ protocol of the IEEE 1394 High Performance Serial Bus. In March 2001 a workshop on this topic was held in association with the FME conference in Berlin. All but the first paper in this issue are derived from presentations given at that workshop. The mechanisms for invitations to submit papers for this issue and their subsequent refereeing etc. are detailed in the first paper which also introduces the task that was undertaken.

Symbolic transition systems separate data from process behaviour by allowing the data to be uninstantiated. Designing an HML-like modal logic for these transition systems is interesting because of the subtle interplay between the quantifiers for the data and the modal operators (quantifiers on transitions). This paper presents the syntax and semantics of such a logic and discusses the design issues involved in its construction. The logic has been shown to be adequate with respect to strong early bisimulation over symbolic transition systems derived from Full LOTOS. We define what is meant by adequacy and discuss how we can reason about it with the aid of a mechanized theorem prover.

Although the formal method VDM has been in existence since the 1970s, there are still no satisfactory tools to support verification in VDM. The paper deals with one possible means of approaching this problem by using the PVS theorem-prover. It describes a translation of a VDM-SL specification into the PVS specification language using, essentially, the very transparent translation methods described by Agerholm (1996). PVS was used to typecheck the specification and to prove some non-trivial validation conditions. Next, a more abstract specification of the same system was also expressed in PVS, and the original specification was shown to be a refinement of this one. The drawbacks of the translation are that it must be done manually (though automation may be possible), and that the "shallow embedding" technique which is used does not accurately capture the proof rules of VDM-SL. The benefits come from the facts that the portion of VDM-SL which can be represented is substantial and that it is a great advantage to be able to use the powerful PVS proof-checker.

In an earlier project of VanInwegen and Gunter, the dynamic semantics of the Core of Standard ML (SML) was encoded in the HOL theorem-prover. We extend this by adding the dynamic Module system. We then develop a possible dynamic semantics for a Module system with higher-order functors and encode this as well. Next we relate these two semantics via embeddings and projections and discuss how we use these to prove that evaluation in the proposed system is a conservative extension, in an appropriate sense, of evaluation in the SML Module system.