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UTILIZING CASE-BASED REASONING PRINCIPLES IN TECHNOLOGY INTEGRATION EDUCATION
Issues Teachers are often required to work in isolation. As a result, there are four interrelated issues that arise. First, while teachers may spend time outside of their teaching experiences planning and collaborating with other teachers, when the time comes to conduct the lesson or the learning experiences, the teacher is often left to do the teaching alone. This means that teachers many times do not have the support or the assistance that they need in order to effectively use technology. Second, while many teachers have successful technology integration experiences, the successes occur away from other teachers and therefore, they do not have the opportunity to share their experiences. Third, the knowledge of how to effectively integrate technology into teaching practices is rooted in experience and is learned through the result of actions. This type of learning is difficult to elaborate and communicate to others. Finally, many school districts have only a few teachers who hold most of the technology integration knowledge. When these teachers leave the district, the knowledge that they have leaves as well. These issues can all be addressed by designing methods to assist teachers in sharing their successes and failures with their colleagues; providing opportunities for teachers to learn from each other by sharing in the experiences of practicing teachers; recording and storing the experiences of teachers in order that the knowledge they hold is not lost; and increasing the size of the community of teachers integrating technology into their teaching practices. These principles can be met through the use of a system designed upon the principles of case-based reasoning. Case-based Reasoning Case-based Reasoning (CBR) is based on the idea that learning attained from a past situation can be adapted to fit a new situation. This is the natural response of humans faced with a problem. We tend to assess the situation, search our memory for past experiences similar to the current situation, seek out the experiences of peers and colleagues, and adapt and apply those lessons learned to the new situation. The CBR process can be broken down into the following steps (Allen, 1994):
CBR has emerged as a promising method to build knowledge-based systems because of its simplicity (Watson, 1997, Watson, 1999). The concept of CBR follows the process that humans use to solve problems. A CBR system based on the nearest neighbor algorithm captures the knowledge gained through experiences and indexes those experiences according to pre-defined structural features. This allows previous knowledge to be retrieved and adapted to fit current situations and to solve problems. In contrast, rule-based systems require the extraction of “rules” in a knowledge domain in order to solve a problem. Any need to change the rules in a system can be time-consuming and costly. CBR systems, however, can be built without the difficult process of extracting the rules, and therefore can be much easier to adapt and build. In addition to the simplicity of the system, another advantage of CBR includes the ability for the system to support problem solving in ill-structured domains, where rule-based systems are bound to fail. CBR systems also offer users concrete examples in the form of cases, which can assist the user in problem solving. Novice users can benefit from perusing the experiences of experts solving similar problems. Asking novices to study and apply the lessons learned from expert teachers allows the novices to be peripheral participants in the community of practice and giving them the opportunity to learn the language and practices of the teaching community. The KITE Project The Knowledge Innovation for Technology in Education (KITE) project is a collaboration of eight teacher education programs. The team is comprised of the University of Missouri-Columbia as the lead institution and seven other universities. The KITE project has developed a system utilizing CBR in order to teach pre-service and in-service teachers how to effectively integrate technology into their teaching practices. The goal of the project was to build a CBR knowledge repository containing technology integration experiences, thereby enabling learning through sharing, communal understanding through storytelling, continuous exchange and creation of new knowledge, and collective problem solving (O’Dell & Grayson, 1998). Figure 1. The three levels of the KITE knowledge repository The KITE Knowledge Repository The second tier is the case base. With more than 1000 cases ranging across grade levels and subjects, the KITE case library allows users to seek out cases that are similar to their situation. The cases in a CBR system have three functions (Kolodner, 1993): 1) They provide contextual information to help with understanding or assessing a new situation. KITE cases are captured through the use of “knowledge scouts”. Each of the seven partner institutions employed knowledge scouts, who were responsible for gathering technology integration experiences from teachers in their areas. They contacted local schools, met with practicing teachers and interviewed the teachers, asking them to share their technology integration experiences. The teachers shared their experiences and the transcribed interview was then indexed according to the KITE indexing structure. The cases were then proofread and a rubric was applied assure that the case information met the standards set by the case development team for case completeness. The case was then added to the knowledge repository. The KITE CBR search engine is the final tier of the KITE system. The cases in a case library can be used for a variety of purposes, but without a search mechanism the cases would be worthless. The search engine is designed to function similar to the human thought process in that people tend to recall similar situations when encountering a new situation. The focus of the CBR search is to retrieve cases that have semantically similar meanings. This allows the user to present a problem case and find similar cases containing possible solutions to the problem case. A CBR search facilitates the CBR process for reasoning and learning. Figure 2. Major components of the KITE CBR engine Figure 3. A query case example: A 4th grade Math teacher in an urban elementary school looks for previous cases in a similar instructional situation As an EPSS As an Instructional Resource Figure 4. Sample of a TILE scenario
As the Medium of an Online Learning Community Lessons Learned Through the process of designing and developing the KITE knowledge repository, there arose a number of issues pertaining to the CBR system and the user interface. Development of the search engine, including case representation and case quality, and the design of the user interface were the most challenging issues. Case Representation The domain features selected to represent the domain of technology integration in KITE cases included the grade level, subject area, teacher’s years of experience, goal of the technology integration activity and outcome of the activity. These features represent or index each story as a case. For example, a teacher looking for information about teaching 12th grade American history using the Internet and publishing software could input those features into a CBR search interface and would find cases similar to the context requested. The weight of the features allowed importance to be placed on features that were more important to the KITE knowledge repository users. Teachers participating in a formal evaluation of KITE indicated that the most important features of a KITE case were the subject and grade level. If a teacher is searching for information about integrating the use of a digital camera in a 4th grade science activity, they would prefer to find cases related to science and lower grade levels rather than focusing on the technology used. The options given for each index can be numerical, where the years of teaching experience can be selected from 1-35; or they can be non-numerical, with a finite list of text values. School location, for instance, would have the options for rural, urban, suburban, etc. These set the values used for determining the distance in the algorithm. The key to the CBR search is the similarities between cases. In order to calculate the similarity between two cases, the weighted average of all option distances is taken. A shorter distance between the two cases indicates more similarity. The implications for the careful consideration of all these parameters can be seen not only in how cases are represented in KITE, but also in how the knowledge scouts conducting interviews gathered the information needed. Changes to the parameters after interviews have been conducted and stories gathered causes great difficulty in attempts to refine the cases and the search engine. The development of a structured indexing scheme allows the knowledge scouts to gather the important information needed for a complete and worthwhile case. In developing the KITE index structure, a technology integration expert was consulted to propose the initial indexing scheme, followed by review from two teachers experienced in technology integration. The entire team then discussed resulting disagreements and adjusted the scheme as needed. A similar process was used in developing the weighting matrixes for the feature options. After 300 KITE cases had been placed in the knowledge repository, extensive testing was done to determine search accuracy. If the search results did not match with the evaluation participant’s expectations, the case values were examined to determine changes that should be made in the weighting. In addition to search accuracy, it was important to be sure that the results from the CBR search were high quality cases with important information provided. Case Quality A number of measures were taken throughout the project to assure that the knowledge scouts collected quality stories. During the first year of the project, a needs assessment was conducted and the results were used to train the knowledge scouts. Support mechanisms were put in place. A job aid was developed which included an interview protocol. A web-based tutorial was developed in order to help new knowledge scouts learn the process. The tutorial included interview tips shared by experts, information on the types of questions to be asked in the interview and techniques for interviewing, good examples of indexed stories to provide a benchmark for scouts, and a set of trial stories for knowledge scouts to practice indexing. We found that knowledge scouts who participated in indexing other knowledge scout interviews were able to be more successful in conducting interviews. They were more aware of the information needed to complete the case and more familiar with strategies that they could use in interviewing. In addition to the support tools developed, a rubric was created to judge case quality. The rubric counted the number of predetermined required index terms required in order to contain sufficient details to adequately portray the technology integration experience. When the rubric was first developed, a “spot-check” was done on cases already in the knowledge repository using a randomly selected 20% of cases available. We found that a surprising 49% of cases did not pass the rubric. Following this check, we took steps to remedy this by meeting with all the knowledge scouts and conducting a more intensive training session. Successful scouts were asked to share their experiences and the case development team determined to provide the scouts with more immediate feedback on the cases that they submitted. An updated job aid was also provided. The rubric was not only used to check cases once they were in the repository, but the knowledge scouts were also asked to apply it to each case prior to submission. The passing rate for cases following these measures has increased to 84%. Interface design Conclusion The sharing of experiences for learning and innovation has been a part of the human culture across the ages. Stories are the most natural method for sharing experiences as the human brain is designed to better understand complex issues when the information is set into context. The KITE knowledge repository is a useful tool for capturing, storing and sharing the experiences of teachers in many different locations. The CBR system allows members of a community, spread across time and place, to learn from each other and improve their teaching practices. Cases that are stored in the knowledge repository can reach a wider group of people and can be kept in the “memory” of the system, preserving the experiences of its members. The lessons learned through the use of CBR for education and knowledge sharing, as seen in the KITE project, can be applicable to any number of domains. The KITE system has been designed to be adapted in order to fit a variety of different needs. Future plans for systems at the University of Missouri include a field experience system for pre-service teachers to share the knowledge that they have gained in clinical experiences in local schools and an entrepreneurial experience system for people starting small businesses. By utilizing the concept of CBR, knowledge gained by one person can be explicated and stored in the memory of the system. This knowledge can be easily accessed and adapted to fit the needs of many users, expanding the possibilities for learning and self-improvement. References Allen, B. P. (1994). Case-based reasoning: Business applications. Communications of the ACM. 37(3), 40-42.
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