< Previous | Next >

The ChemCollective Digital Library

2. Support for collaboration between community members

Creation of effective online educational materials requires contributions from at least the following three types of expertise:

• Learning technologist: We will refer to this contribution as programming, although it includes any contribution (databasing, networking, etc.) that goes beyond the expertise required to use an office suite (such as Microsoft office/Frontpage) to author simple web materials.


• Content expert (instructor): By this we mean expertise in both the subject matter and the classroom environment.


• Learning scientist: By this we mean expertise in pedagogy, cognition, and assessment.

Although these areas of expertise do not necessarily reside in different individuals, it is rare to find individuals possessing all three types of expertise. Projects such as VANTH (http://www.vanth.org/) and Escot (http://www.escot.org/) have pursued models of synchronous collaboration by forming development teams consisting of the above three types of experts. Our goal was to enable a collaborative process that is spatially remote and temporally asynchronous (loose coupling), but that continues to bring the above three areas of expertise to bear on materials development.

2.a. Learning technologist

The primary means through which we enable the contribution of learning technology is through an approach we refer to as "Configuration-as-Authoring", which successfully engages nonprogrammers in the construction of active educational content. In Configuration-as-Authoring, an educational technologists contributes a highly-configurable software program (virtual lab, simulation, multimedia presentation tool, etc.) to the community. Community members without that level of technological expertise may then create sophisticated learning activities, for instance by configuring the ChemCollective virtual lab for a particular type of experiment. The simulation writes a configuration file which students can then load to engage in the activity. Other examples of such an approach are Interactive Physics 2000 (http://www.design-simulation.com/IP/index.php) and the AgentSheets tool (http://www.agentsheets.com/). Sharing of Mathematica and Maple worksheets may be taken as an extreme example, in which the software tool is very highly configurable.

2.a.i. Virtual labs

The ChemCollective virtual lab (http://www.chemcollective.org/vlab) provides a simulation of solution chemistry which can be configured by specifying:

Figure 1. Screenshot of the virtual lab

• Chemical species and reactions. This allows authors to add new chemical to the lab by specifying their thermodynamic properties (heats of formation and standard entropies) and the chemical reactions in which these species participate. These can include fictional materials, such as acids with randomly generated dissociated constants (for unknown identification activities) or idealized biological molecules such as proteins and drugs (for use in activities that are set in biological contexts).


• Solutions. The virtual lab stockroom can be configured to contain any desired solutions. This process is similar to setting out starting materials for a physical lab.


• Viewers and instruments. This allows the author to control access to instruments, such as the pH meter and thermometer, and viewers, such as the list of all chemical species in a solution and their concentrations. For instance, an unknown-acid activity would necessarily need to turn off the chemical species viewer. Access to the pH meter could be provided, or withheld if the author wants students to use a pH indicator such as phenolphthalein.


• Transfer bar. The virtual lab provides three means by which students can transfer chemical solutions between containers. The first is "precise transfer" in which students type in a specific volume. This is useful if the goal is to focus student attention on the chemistry without paying attention to experimental technique. The second is "realistic transfer" in which the volume transferred depends on how long an onscreen button is depressed. This is calibrated such that the attainable accuracy reflects that possible in a real lab. This requires students to use reasonable glassware, such as a buret for a titration. The third is "significant figures transfer", which is similar to precise transfer except that students must enter the desired volume using the number of significant figures possible with the giving glassware. This mode of transfer was suggested by a community member and assessment by that community member indicated that this mode was more substantially effective in teaching the concept of significant figures than any of their extensive previous attempts.
• Activity Description. An HTML description of the activity can be included, which the student can view from directly inside the virtual lab.

The above functionality provides authors with considerable flexibility in the design of virtual lab activities. The configuration is specified in an XML file. The XML file can be altered with any text editor, however, one must adhere to a fairly rigid set of formatting rules. To make it easier to configure the lab, we also created a virtual lab authoring tool that provides a graphical tool for configuring the virtual lab. This authoring tool saves the configuration to the required XML format. We have found, however, that the XML file is sufficiently easy to edit directly that most users either opt to do so, or simply send us all the required information and we create the configuration file.

2.a.ii. Tutorials

We have also been working on Configuration-as-Authoring approaches to creation of tutorials. Our tutorials consists of online explanations with embedded assessments. A number of tools exist for authoring and delivering assessments, including Blackboard and WebCT (which store assessments in XML files based on the IMS QTI specification, http://www.imsglobal.org/question/). To allow a more flexible approach to providing students with hints and feedback, we have used both javascript and assessment tools developed by the OLI project. Such tools are continuing to evolve both in terms of sophistication (see, for instance, the Cognitive Tutor Authoring Tools at http://ctat.pact.cs.cmu.edu/) and ease of use (see, for instance, http://www.blackboard.com/).

Similarly useful tools for creation of online explanations are, however, currently lacking. Video captures of lectures are one option, and with the success of projects such as OCW at MIT ( http://ocw.mit.edu/), such captures seem likely to proliferate on the web. While not without merit, such video captures have a number of potentially serious drawbacks including high bandwidth demands and a content format that is difficult. The difficulty of modifications makes it difficult for the community to participation in the evolution and improvement of the materials over time. At the other extreme of development time are materials with high production value, for instance, materials created using flash. Our stoichiometry tutorials were created directly in flash, through a time consuming and tedious development process. Such presentations are also difficult to modify, because the time that goes into the original production can be huge, and it is difficult to get the authors motivated to invest even more time into making large changes.

Figure 2. Screenshot of the EX2 Player

The EX² system we are currently developing is meant to provide a more convenient means to create and modify online instructional explanations. The system assumes a standard lecture cycles through writing something on the blackboard and then talking about what was written. In our system, the author writes an object on a table computer, and annotates it with what they would normally say in the classroom (in audio, text or both). The outcome of the authoring process is an XML file with a list of objects and associated annotations. The viewer of this content is written in flash. The content is modifiable because one can rearrange the objects, insert new objects, alter the annotations, easily cut and paste to make alternative sequences, etc. It is also easier to use than video because it can be viewed in multiple modes: lecture mode (currently available) shows the objects in sequence while review mode (not yet available) will show all objects at once and allow one to click to see or hear desired annotations. This system was used to create instructional explanations for our equilibrium tutorials. We currently have a first version of an EX² viewer, but the content is authored through a process requiring considerable expertise with the XML format. We are hoping to begin development a graphical authoring tool that will make creation of EX² content nearly as efficient as video capture.

2.b. Content expert/instructor

The ChemCollective has been quite successful in engaging instructors as authors of new materials which they then contribute to the collection. Of the 117 virtual labs in the collection, 56 were contributed by 11 different user groups. Many of these contributions were created in collaboration with ChemCollective staff. Instructors submitted ideas for their activity, and these were implemented locally. In addition, use of the authoring tool described above is growing. The community contributions have substantially increased the diversity of the collection, since many of the topic areas and approaches are outside that which we would have developed on our own.

2.c. Learning scientist

Learning science contributed to both the design and evaluation of the collection and its contents. Much of the development of virtual laboratories, scenarios and tutorials for the ChemCollective was done with strong, but local, collaboration between developers and learning scientists. This effort was organized through biweekly meetings involving in depth discussions of design issues such as learning goals and level and types of feedback. This team also designed and carried out the assessment efforts (see next section) which involved extensive observation of student problem solving and analysis of artifacts from student assignments. These student observations fed back extensively into the modification of existing materials and the choice and design of new materials.

Learning science also contributed technical approaches to the collection of data for learning assessment. The virtual lab is now instrumented to save all student actions to a log file. We are working with the Pittsburgh Science of Learning Center (http://www.learnlab.org/) on the challenging task of extracting useful information regarding use and learning from such log files.

< Previous | Next >