Go to the Crisscrossing demo website. Use "demo" for both the user name and password.

The purpose of this project is to develop a collaborative authoring tool of non-linear hypertexts by learners. The design considerations, the tools and web-applications, and results of our research studies arose from an emerging question that we faced in numerous projects and learning experiences: How to integrate complex non-linear content structures into case-based activity systems for better learning effects?

The current iteration of Crisscrossing environment is built as an open shell that could later be adapted to a multitude of complex tasks including various kinds of problem-solving environments. So this iteration of Crisscrossing consists of a browser based web interface to allow remote access from various locations and to provide cross platform compatibility. It is developed using a combination of server-side (PHP) and client-side (JavaScript) scripting technologies, assisted by a database (MySQL) that stores both the students' work and the system settings.

Crisscrossing allows the students or the instructor to construct three types of entities: documents, links, and paths. A document is a named entity composed of any type of text, markup language, links, and linked multimedia. It is defined by a combination of a type and a category, predefined by the instructor during the initial environment setup. The link construct is directional and is designed to allow the user create a relationship between two existing documents. Similar to a document, the link is defined by a name, a type (predefined by the instructor during the initial system setup), as well as a description which allows the user to provide a rationale for creating it. To provide support for more systematic learning, Crisscrossing provides a third construct, the path. It allows the users to create an ordered sequence of documents (publicly available in the system). The learner is thus able to follow a predetermined learning trajectory that is designed by the instructor or to create a trajectory that is representative of his/her understanding.

The environment allows the instructor to specify a number of initial settings that limit the number of constructs the learners can use and provide basic guidance for their work. The instructor can define the status of each construct (e.g., allowing the learners to keep their work private or to share it with the others). The instructor can also define documents types, categories, and type/category combinations (e.g., themes or perspectives, problems and solutions). Finally, the instructor can define types of links. The learners define coherent and representative names for documents and links, as well as providing content or explanations for each of them. The ability to edit and delete any of the available constructs creates the foundation for an iterative and interactive approach to building hypertext.

In order to help learners build, revise, and use the environment, we provided a number of navigation mechanisms. The main navigation mechanism uses a combination of document and link views. The document view (Figure 3) provides an organized list of links and linked documents represented as hyperlinks. The link view shows the two linked documents side by side, with the link information displayed in between. Each document name is represented by a hyperlink which when clicked would open the document view window.

A second navigation mechanism borrows its functionality from concept mapping applications. It allows the learner to view a central (focus) document accompanied by the documents it is linked to and from. The view page provides a multi-layered approach. On one side, it provides the ability to navigate the environment a document at a time while on the other side it allows the learner to visualize the documents by link type by dynamically emphasizing the corresponding documents.

Foreseeing potential problems a large generated hypertext might pose to the learner, the environment provides full text search functionality on all constructs. To further support the learner, the search function will display the resulted constructs only if their number is less than half of the number of similar constructs currently contained in the environment.

Building on the benefits of group learning and social construction of knowledge, another innovation to the Crisscrossing environment supports group work. In addition to collaboratively building the hypertext, the learners are able to filter the displayed constructs to his or her own, to those owned by the group he or she is part of, or to show all the documents that are released public in the environment. To support both individual and collaborative work, the environment allows users to specify the status of each of the available constructs. In this way, learners can work on a private document, available only to himself/herself. When done the learner can make the construct public by releasing it to the environment.

From our prior research the need for hypertext visual depiction emerged. Therefore, a graphical mapping module was added to the environment. It presents the hypertext structure as a directed graph over which a layer of hypertext links to the actual constructs (document and links) is added. This development allows the learners not only to visualize their work, but also with another navigation mechanism.

Go to the Crisscrossing demo website. Use "admin" for both the user name and password.