Applications

This section gives a broad, but not necessarily exhaustive, overview of applications of con-cept maps that have been reported in the literature. Their first and most extensively studied applications have been, due to their origin, in the area of education. Other applications in-clude library access, ontology creation, expert training or web search.

Nesbit and Adesope (2006) performed an extensive meta-analysis on the effects of using concept maps during teaching for which they selected 55 high-quality studies with a total

5Note that the example in Figure 2.1, although regularly used in introductions of concept maps, violates this principle. The triple(perceived regularities or patterns - in - events (happenings))(bottom left), among others, depends on(concepts - are - perceived regularities or patterns)to be meaningful.

6https://cmap.ihmc.us/

2.2. Concept Maps

of 5,818 participants. In 25 studies, students created new or modified existing concept maps.

With regard to knowledge retention and transfer, these activities were found to be more effective than reading texts, attending lectures or classroom discussions and slightly more effective than constructive activities such as writing summaries or outlines. These findings were consistent across a broad range of educational levels, subject areas and experimental settings. In the other 30 of the analyzed studies, students merely studied provided con-cept maps rather than constructing them. Also in this setting, concon-cept maps were found to be more effective for knowledge retention than studying text passages, lists or outlines.

For both settings, the researchers point out that while the observed findings are significant, more and larger-sized studies are needed to better understand the effects and the conditions necessary to observe strong benefits. With regard to reasons for concept maps’ effective-ness, they point out that the empirical findings are “consistent with theories that concept maps lower extrinsic cognitive load by arranging nodes in two-dimensional space to repre-sent relatedness, consolidating all references to a concept in a single symbol, and explicitly labeling links to identify relationships” (Nesbit and Adesope, 2006).

An alternative application of concept maps in education is as a testing tool. Edwards and Fraser (1983) performed an early experiment with 24 nineth-grade students in which they assessed the student’s science knowledge by letting them write reports or create con-cept maps on a given topic. They compared the assessments to the results of interviews, a technique which is known to be most accurate (but time-consuming) to evaluate a students’

understanding of science concepts. They found that the reports mostly underestimated the students’ understanding as determined by the interviews, because students gave incorrect, incomplete or ambiguous written answers. Using concept maps, they were able to more clearly express their understanding and the results aligned better with the interviews.

Later work by McClure et al. (1999) further strengthens the argument to use concept mapping as an assessment tool in schools. The authors conclude that scoring concept maps created by students yields reliable evaluation scores and that the required effort, consist-ing of trainconsist-ing the students in concept mappconsist-ing, havconsist-ing them create concept maps on the test topic and letting a teacher score the maps, is comparable to other testing methods.

However, they observed that the reliability of the scores depends on the technique used to score the student maps. In addition to the examples outlined here, many more studies have been conducted on using concept maps for educational purposes, including most papers presented at the aforementioned biennial International Conference on Concept Mapping.

Besides the educational domain, concept maps have been regularly used to structure information repositories and provide means of easy access and navigation to users. Carnot et al. (2001) conducted a first study that compared the performance of 62 students who were given questions on developmental psychology. All students had access to the contents of an introductory book chapter on that topic, which was provided either as a concept map, as a simple text with hyperlinks covering the same content or as a multimedia-enriched

Chapter 2. Background

and more verbose web page. Concept map users answered significantly more questions correctly, leading the authors to conclude that concept maps successfully support users that try to navigate and find information. The group using the reduced text interface did not perform better than the one using the more verbose web pages, indicating that it is not only the reduction of content but also the form of the concept map that is helpful. A similar study by Valerio et al. (2012) observed large improvements in response time at only small drops in accuracy when answering questions given a concept map instead of the source text, even when the map had been automatically generated from the text.

Practical applications have been reported by Hoffman et al. (2001), who created concept maps to represent expert knowledge about weather forecasting and to provide access to a repository of learning materials for their employees, and by Briggs et al. (2004), who used concept maps to provide access to a large multimedia repository explaining the NASA’s activities to explore Mars. The Mars concept maps were made available online and the authors report a large interest from the public. Gaines and Shaw (1994) report using concept maps, in addition to other knowledge representation techniques, to collaboratively capture shared knowledge in large research projects. The work by Shen et al. (2003) and Richardson and Fox (2005) proposes to use concept maps to provide access to library contents and describes their ongoing efforts. They argue that concept maps created for books or book chapters would be easier for a user to consume than an abstract and that they can be used to effectively provide an overview and summarize contents. They also express their desire to use automatic methods to create the concept maps and later report on first steps that they have taken in that direction (Richardson and Fox, 2007).

Carvalho et al. (2001) use a concept map as the context for a traditional web search and develop algorithms that rerank retrieved web pages based on the content and structure of the concept map. Lee (2004) also uses concept maps in the area of search engines and presents a system that lets a user organize queries and their results in a concept map that is constructed throughout the search session. However, what they call a concept map is very different from a Novakian concept map. Leake et al. (Leake et al., 2003, 2004, Cañas et al., 2004) propose to use search engines to support users creating a concept map. They develop several algorithms that construct queries from the content of a partial concept map in order to retrieve documents that help the user find additional concepts and relations for the map.

Another application domain is writing support, which Villalon et al. study in their research (Villalon and Calvo, 2008, 2009, Villalon, 2012). Their idea is that concept maps constructed from student essays can be a valuable tool for the students to improve their writing, as the maps provide a visualization of the content and structure of the essay. To-wards that goal, they develop algorithms to automatically create concept maps from student essays, annotate a corpus for the task, propose evaluation metrics and integrate their meth-ods into larger writing support systems. We will revisit the different parts of their work in detail in later chapters of this thesis.

2.2. Concept Maps

Due to their similarity with formal knowledge representations, automatic methods to create concept maps from text have also been applied to create domain ontologies. For that purpose, algorithms as presented in Section 2.3.1 can be combined with additional filtering and conversion steps, partly automating a laborious process that is usually done manually by domain experts (Zouaq and Nkambou, 2008, 2009, Zouaq et al., 2011).