An Architecture for Case-based Learning

44 TechTrends • November/December 2010 Volume 54, Number 6

AbstractWe report on the design, development,

implementation, and evaluation of a case-based instructional environment designed for learning network engineering skills for cybersecurity. We describe the societal problem addressed, the theory-based solu-tion, and the preliminary testing and eval-uation of that solution. We identify an ar-chitecture for scaffolding case-based learn-ing for problem-solving to inform design of case-based learning environments.

Keywords: Case-based learning, cogni-tive flexibility theory, intelligent tutors, on-line learning environments, problem-based learning, instructional software, network engineering, cybersecurity

e present here design, development, implementation, and evaluation of a case-based instructional environ-

ment for teaching and learning network engineering for cybersecurity. Computer Science programs need to prepare the cy-bersecurity workforce by engaging students in interactively solving intellectually challeng-ing cybersecurity problems. The Web-Access Exercise System (WAES) provides students with opportunities for hands-on network engi-neering experience by using an online labora-

tory (http://waes2.tamu.edu; http://vtech.tamu.edu). Through the WAES, we currently engage network engineering students in fifteen under-served community colleges around the country in case-based cybersecurity problem-solving. Students focus on technical solutions to secure networks. The WAES is instructionally innova-tive and differs from conventional teaching labo-ratories in that it does not require students to be physically located with the network equipment they are learning to manipulate. Instead, the WAES offers a technologically innovative online laboratory for students to remotely manipulate equipment in a real network and conduct cased-based problem-solving exercises in a controlled, high-fidelity environment via the Internet using their web browsers. The WAES enables instruc-tion to be efficiently and effectively distributed across geographic regions, thereby reaching greater numbers of students than would be pos-sible through traditional face-to-face or on-site laboratory instruction.

Case-based learning was chosen as the in-structional approach because novices needed to learn how to gain and refine their expertise at solving real-world cybersecurity problems. Con-structivist learning theory suggests that such problem-solving is best learned in the context of problem, project, or case-based learning envi-ronments, which provide experiences that facili-tate knowledge construction (Jonassen, 1997).

An Architecture forCase-based Learning

By Laurent Cifuentes, Rene Mercer, Omar Alverez, and Riccardo Bettati

W

“The WAES is instructionally innovative and differs from conventional teaching laboratories in that it does not

require students to be physically located with the network equipment they are learning to manipulate.”

Volume 54, Number 6 TechTrends • November/December 2010 45

The Practical ProblemIn order to better harness the potential of the

Internet, current and future engineers must gain an understanding of medium-to-large scale net-worked cyberinfrastructure and must be trained to design, develop, deploy, and operate the net-works for such systems. The security of our na-tion’s technical infrastructure depends upon in-dividuals and people running businesses, partic-ularly small businesses, coming to understand the cyber landscape and how to protect their in-vestments and assets as managed on computers. Such audiences are spread across America and are often served by community colleges that in many cases cannot afford to design or run cyber security programs of their own. America’s com-prehensive strategy for cyber security requires training individuals and small businesses to se-cure their own parts of cyberspace, as gaps in the security of one group of cyber participants can be a conduit through which other participants are attacked. In light of this, the need for train-ing individuals who manage small enterprises is particularly acute, as they frequently have the least knowledge of cybersecurity, and thus are among the most vulnerable.

Unfortunately, there is a dearth of instruc-tors with expertise in cybersecurity, particularly in rural parts of our nation. In addition, tradi-tional hands-on laboratories on network equip-ment are inherently expensive, both in terms of capital outlay for equipment and in terms of labor cost for operations and management. Without expert instructors or laboratory equip-ment for hands-on learning, students, and sub-sequently the workforce, are ill prepared to ad-dress cybersecurity problems.

The Solution Framed in Distributed Cognitions andCognitive Flexibility Theories

Design of the case-based WAES is framed by two synergistic learning theories, distributed cognitions theory (Salomon, 1997) and cogni-tive flexibility theory (Spiro, Fletovich, Jacobson, & Coulson, 1991) which are undergirded by the philosophy of social-constructivism. Accord-ing to distributed cognitions theory, learning is driven by the wish to solve problems perceived by the learner, and ability to solve problems is achieved through real-world experience. Today’s instructional designers advocate for learning en-vironments where instructors require students to engage in performance-based activities such as collaborative problem-solving (Jonassen, 1997). Distributed cognition is a critical tenet of en-

gaged learning – where a social learning com-munity is energized by personal responsibility for one’s own learning and for contributions to others’ learning. Engaged learning features tasks that involve active cognitive processes such as creating, problem-solving, reasoning, decision-making, and evaluating. Distributed cognitions theory proposes, “knowledge is commonly socially constructed, through col-laborative efforts toward shared objectives…” (Pea, 1997). According to the theory, intelli-gence is not solely an attribute within individ-uals, but is generated collaboratively in com-munity. Bringing multiple experts into a learn-ing environment distributes expertise among learners. Students seek different forms of sup-port from instructors, their peers, colleagues, and other community members (mentor-ing, coaching, modeling, mediation) (Fosnot, 1996). Tools in the physical environment serve as mediating structures that shape and direct human activity; and human activity emerges from human need. Resources that shape and enable activity are distributed in configuration across people, environments, and situations so that “intelligence is accomplished rather than possessed” (Pea, 1997).

The fundamental premise in Spiro’s cogni-tive flexibility theory (Spiro, Feltovich, & Coul-son, 2004) is that multiple perspectives must be available to learners in a knowledge domain so that learners can flexibly build understanding. Well-designed instruction provides conditions that facilitate cognition that is flexible enough to transfer to circumstances other than those the student encounters during instruction. Spiro has shown that a well-designed hyper-text environment can facilitate such cognitive flexibility. First, the theory emphasizes the im-portance of embedding multimodal represen-tations of to-be-learned content in complex, case-based scenarios. Second, it recommends that learning activities provide multiple repre-sentations of content in order to support learn-ers as they build mental models. Third, the theory describes ways that hypertext instruc-tional environments avoid oversimplification of content and support context-dependent knowledge. Fourth, cognitive flexibility theory suggests that knowledge sources be highly in-terconnected rather than compartmentalized. Case-based learning environments meet the Spiro’s four recommendations.

Cybersecurity content is presented in the WAES in the format of case-based learning as suggested by cognitive flexibility theory (Spiro, Fletovich, Jacobson, Coulson, 1991; Jonassen, 1997). Case-based learning is widely used in


professional education to engage learners with real world situations in order to give to them the expertise required to be successful in the workforce. A case serves as a representation of real-world phenomena and is a safe, yet mean-ingful context in which students can develop understanding of the complexity of network engineering. Jonassen and Hernandez-Serrano (2002) describe the case-based reasoning cycle as the presentation of a new problem-case to solve. Given a case, learners apply previous ex-periences and general knowledge to solve the case, suggest solutions, test their solutions, re-vise their suggestions, and confirm solutions. During the cycle, learners retrieve, reuse, re-vise, and retain understanding until expertise

is gained from the problem-case. Expertise is derived from expert scaffolding and experience in the case’s content domain; in cybersecurity, such scaffolding and experience are both hard to come by and are impractical for novices.

Based upon the two theories described above, the WAES system was designed to provide nov-ices with opportunities to gain expertise and cog-nitive flexibility in cybersecurity from multiple experts through multimodal experience in the context of real-world problems. Such real-world problems are presented to students in sequences of simple scenarios and increasingly complex cybersecurity cases to be solved. Through these scenarios and cases, students build mental mod-els that they can draw upon for future problem-solving. The WAES provides for both distributed expertise and hands-on experience with real-world cybersecurity problems making it an ideal environment for testing distributed cognitions and cognitive flexibility theories.

Developing the Web-AccessExercise System

The technical architecture for the environ-ment is represented in Figure 1. The learner can experience the environment autonomously or with the help of an instructor.

We provide for continuous improvement of WAES instruction through implementation cycles of development research, evaluation, and revision. Our design and development system for constructing the case-based learning environ-ment involves a cycle of rapid prototyping pro-cesses that undergo continuous evaluation by the design and development team and a sample of users. Priorities for topics to be taught in units of instruction are set by the expert faculty in com-munity colleges around the United States. Cogni-tive task analyses provide the foundation for the scope and sequence of each unit (Jonassen, Tes-smer, & Hannum, 1999). Based upon the content described in a given task analysis, cases are de-veloped that include ability to perform all tasks for that topic. To scaffold the ability to solve each cybersecurity case, instruction within each topic is modularized and scenarios that compose the tasks for the larger case are developed for each module. Then exercises including assessments are developed for each scenario (see Figure 2).

Ability to solve problem scenarios for each topic involves a network technician’s problem-solving skill within that topic. Each case pres-ents sufficient detail to make the case motivating without causing students to focus on extraneous information. A case includes a main character, events and reactions by the main character,

Figure 1. The WAES technical environment.

Figure 2. Rapid prototyping process for developing the solution.


responsible. Your team also needs to secure the network in order to protect the customers’ information. The goal of the team of network engineers is to find out what happened and prevent it, or anything similar, from happen-ing again to TriCity Bank.

The unit of instruc-tion that prepares stu-dents to solve the fire-walls case serves as an example of the structure of the learning environ-ment. In order to address cybersecurity issues with firewalls, task analysis revealed that network en-gineers need to be able to align a network topology with security require-ments, configure net-work access control and logging, and protect in-formation flow through encryption, and VPNs. The full-range of skills re-quired for addressing the complex case is described in Figure 3. Once students have mastered each of the skills, they should be able to address the case.

problems to solve in a real-world context, a description of how to demonstrate that an acceptable resolution to the problem has been achieved, and a call to solve the prob-lem. For instance, the case presented in the Firewalls unit follows:

You just started your first job as a net-work technician at TriCity Bank. One of the reasons you chose this position was be-cause it was located in a rural area where you felt you could gain ex-perience as a network engineer at a relatively slow pace. However, after three weeks, Ben, the Chief Information Officer, approached you and your two teammates to discuss a very serious issue.

Ben seemed more stressed than normal as he began to explain the situation. Melinda, the president of the bank, came in much earlier than expected this morning and asked to speak with Ben right away. While Ben was in her office she told him that the manager of the bank’s fraud de-partment reported an unusual amount of activity lately. An increasing number of calls regarding in-correct account balances have been received and suspicious activity seems to be taking place.

From the information she has been given, it looks as though a hacker may have intruded into the bank’s network and stolen what is now esti-mated to be close to $1,000,000. The funds may have been stolen from various accounts and in small increments; thereby, going unnoticed and affecting many customers. Melinda asked Ben to put his network team on the task of finding out the following information:1. Where did the intrusion come from?2. How did the hacker break the bank’s secure

network?3. How can we prevent this from occurring in the

future?4. What steps need to be taken to implement an

effective solution? Ben has emphasized that you need to discover

whether intrusions came from internal or exter-nal sources; and, if possible, identify who was

Figure 3. Firewalls unit map.

“Well-designedinstruction provides conditions thatfacilitate cognition that is flexible enough to transfer to circum-stances other than those the studentencounters duringinstruction.”


In the WAES, students are initially present-ed with a unit’s case and are told that upon con-clusion of the unit they will have the necessary skills to solve it. Students then work through a series of modules in a flexible sequence. Each module contains scenarios and exercises. Within each exercise is a problem statement, described prerequisites, foundational content, supporting documentation to complete the ex-ercise, activities, and an assessment. In the cur-rent design, activities include performance ob-jectives, directions, the opportunity to submit work, and feedback. Ability to apply the skills taught in each exercise is assessed. Assessment consists of supporting documentation, objec-tives, directions, student performance in the form of completed templates, questions an-swered, or command line interface logs. Once students have successfully completed each of the exercises in a unit, they are able to apply the skills learned in order to successfully ad-dress the initial case that has been well-struc-tured by the case-based learning environment. Solving that case is the next activity in the unit and currently serves as the students’ authentic assessment. Then students are given a novel case to solve to determine whether or not the environment has prepared them to solve ill-

structured cybersecurity problems. Ability to solve ill-structured cybersecurity problems, as those they will encounter in the workforce, can be supported through peer and instructor feedback, and feedback from an embedded in-telligent tutoring system (ITS). Students can be prepared to approach ill-structured problems from a stance of cognitive flexibility through in-teractive opportunities and prompts from peers, instructors, and an automated ITS. The archi-tectural structure for supporting case-based learning is represented in figure 4.

Evaluation and TestingThe instructional designers used forma-

tive evaluation, continuously investigating the WAES’s features in pursuit of establishing the best design (Orrill, Hannifin, & Glazer, 2003; Wang & Hannafin, 2005). Each case, module, scenario, and exercise was constructed through a process involving at least eight iterations with the design team and periodic one-on-one and small group evaluation with the target audience.

The team of developers includes instruction-al designers, network engineers, computer scien-tists, and network engineering instructors who meet and correspond weekly to inform design

Figure 4. CBL model, structure, and scaffolding with interactive opportunities and prompts highlighted.


decisions. One-on-one and small group evalua-tions have been conducted with the target audi-ence, students at a community college. Field eval-uations are scheduled for the upcoming semester.

Documentation, Analysis,and Reflection

The designers collected and will continue to collect data from design documentation, pretest and posttest comparisons, usability and attitude surveys, and faculty and student focus groups. We ask questions such as: Is the activity authen-tic? Is the activity something a network engi-neer would really encounter on the job? Does the terminology used reflect everyday terminol-ogy used by instructors and practitioners alike? Does the activity reflect a competency necessary for understanding and mastering the content? Does the module combine enough or too much information into one exercise? Design docu-mentation involves continuous records of tasks to be done, task due dates, responsible party, and task status. In addition, the lead designers keep journals that include lessons learned during the process. Documentation is constructed weekly. Questions about content, design, technical qual-ity, and attitudes toward the instruction are de-livered in multiple usability surveys, and focus groups. The hundreds of inputs from data con-tinuously inform revision of the WAES.

Preliminary findings indicate that the case-based learning environment provides students with a meaningful learning experience that uniquely prepares them for the workforce. The majority of students who use the WAES have been able to describe the problem that was to be solved in the case and in the scenarios. Ninety percent have felt that the scenario and case are applicable to something they might encounter in an on-the-job situation. Users have been able to pinpoint unclear language for revision and where in the environment they needed more instruc-tion. An important input from users has been the expressed need for clear connections be-tween the contents of modules and the ultimate case. Student’s responses to a Likert scale survey instrument indicated that most agreed that their experience using the WAES system was interest-ing, navigation through the interface was easy to understand and easy to do, and the case-> module->scenario->exercise configuration as de-scribed in Figure 3 was easy to follow and helpful for their learning. Pretest scores reveal that prior to instruction students have discrete network engineering skills but they need instruction that facilitates problem-solving as conducted in case-based learning experiences. Prior to working in

the WAES, they have no skill in approaching real network-security problems or in the plan-ning necessary to solve those problems.

Both instructors and students appreciate the flexibility regarding sequence and par-ticipation provided in the environment. Input from instructors has indicated the need for an instructors’ manual. Instructors also indicated that students may need scaffolding beyond what is currently provided in the environment in order to support students of various abili-ties. Some students find too much guidance in the environment while others express the need for more. Interdisciplinary team meetings re-sult in strategic improvement of the environ-ment and provide graduate students in both Computer Science and Instructional Design with rich professional experience.

Students who use the WAES have reported that they hope to get a job in network engineering in their futures. Most im-portantly, the target audi-ence feels that they have been provided with use-ful training in the WAES to help them get a job in network engineering, and they were doing the real work of a network engi-neer technician while in the WAES system.

Our experience sug-gests that small scenarios scaffold more complex cases, especially when cou-pled with tutoring strate-gies such as guiding ques-tions, clarification, hints, examples/nonexamples, and redirection to sup-port students’ success and cognitive flexibility.

Educational Implications The proposed model can be easily trans-

ferred to a variety of domains, and would be particularly useful in those addressing ill-struc-tured problem-solving. Instruction designed using the case-based learning model provides learners with prerequisite domain knowledge and skills needed to solve novel cases. Domain examples include such ill-structured areas as software engineering, applied mathematics, special education, and architecture. For in-stance, software engineering modules could be represented by software development steps (e.g. analysis, design, implementation, testing, and installation). Each module could be easily subdivided into scenarios addressing skills re-

“Preliminaryfindings indicate that the case-based learning environment provides studentswith a meaningful learning experience that uniquely prepares them for theworkforce.”


quired in that specific module. A de-sign module could address scenarios for specific skills such as design of the interface, database, system structure, and so forth. From there, exercises ad-dressing each sub skill with different levels of complexity could be imple-mented.

The process used for developing the WAES case-based learning envi-ronment illustrates how instructional designers can address societal prob-lems through case-based learning en-vironments. Over the years education-al research has been criticized for hav-ing little practical relevance. Reeves (2000) calls for socially responsible design and development research that addresses relevant, real-world prob-lems. Our architecture for case-based learning provides an elaborate illustra-tion for instructional designers who want to develop meaningful, authen-tic learning environments. The WAES stands as a solution to substantial so-cietal problems of lack of hands-on instruction for training the network engineering workforce.

Design of the WAES environment was based on philosophical assump-tions of social constructivism and on distributed cognitions theory with the intention of supporting collabora-tive knowledge construction among members of a learning community. Design and development research ex-ploring the effects and impacts of the case-based architecture presented here will inform the instructional design field and support grounded theory for design and development of case-based learning environments.

AcknowledgmentsThis work is being made possible

by funding from the National Science Foundation, Cyber-Infrastructure-Training-Education-Advancement-and-Mentoring program.

This work was supported in part by the National Science Foundation under award number OCI-0753408. Any opinions, findings and con-clusions or recommendations ex-pressed in this material are those of the author(s) and do not neces-sarily reflect those of the National Science Foundation.

Lauren Cifuentes is associate professor in the Educational Technology Program at Texas A&M University where she teaches Instruc-tional Design, Integrating Technology into Curriculum, and Computer Graphics for Learning to graduate students. She teaches her classes online to students around the world. Her primary research interests are in design considerations for case-based and proj-ect-based collaborative instructional environ-ments. She investigates visual message design: how messages can be shared and interpreted by learners, how they impact learners, and how their impact can be researched. She has consulted with educators on distance learn-ing, needs assessment, task analysis, design of instruction for multicultural audiences, align-ment in instructional design, and evaluation of instructional materials and programs. [email protected], Department of Educational Psychology, College of Education and Human Development, Texas A&M University, 77840

Rene Mercer earned both her undergraduate (1997) and master’s degree (2004) from Texas Christian University in the field of Mathemat-ics. She has been a Texas educator from 1997 until 2008 when she began her doctoral stud-ies in Educational Technology at Texas A&M University. Her research area focuses on as-sessment within secondary and higher educa-tion. Her current research involves design and implementation of a case-based assessment for an online educational software in cyber-security called WAES. [email protected], Department of Educational Psychology, Col-lege of Education and Human Development, Texas A&M University, 77840

Omar Alvarez Xochihua received an under-graduate Computer Science degree in 1991 (UABC, México) and a master’s degree in 1994 (ITESM, México). He has been a professor in the Science Faculty at Autonomous Univer-sity of Baja California since 1995, where he has taught courses in software engineering, computer programming, and databases. He is currently a doctoral student in Computer Sci-ence at Texas A&M University. His research interests are web-based learning environments, intelligent tutoring systems, and collaborative technologies. His latest work involves an NSF funded project supporting the design and im-plementation of an online case-based learning environment in cybersecurity. His role in this project is the implementation of an Intelligent Tutoring System to provide customized instruc-tion and feedback to students. [email protected], Department of Computer Science and En-gineering, Texas A&M University, 77840.

Riccardo Bettati, professor in the Department of Computer Science and Engineering, serves as director of the Center for Information As-

surance and Security (CIAS) at Texas A&M University. Dr. Bettati’s research focuses on dis-tributed real-time and embedded systems. This includes the study of scheduling algorithms, schedulability analysis, resource access proto-cols, establishment protocols, the appropriate operating system support and middleware, and the overall design principles necessary to effec-tively realize and deploy such systems.

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An Architecture for Case-based Learning