Tuesday, November 7, 2017
With this release of LearnSphere we continue to extend the functionality of Tigris, the workflow tool, as well as enhance it's usability. There is now a 'Recommended Workflows' section at the top of the main Tigris page. This list of workflows contains those we feel best highlight the most useful features of the tool. Using the 'Save As' button, these workflows can be used as templates for users to create their own workflows. In addition, on the main page, there is a search feature that allows users to filter the workflows by name, owner or component.
A focus of this release has been adding support that facilitated the creation of many new components. For example, dynamic options are now supported. This provides component developers with option constraints that can trigger changes to the UI based on the user's selections. Dependencies can be combined in logical combinations to accomodate complex parameter sets.
Similarly, the component definition language was extended to allow for optional inputs on components. These are common in components which generate data and also take an optional set of inputs or parameters. An example of this is the new Tetrad Graph Editor. Tetrad is a causal modeling tool that allows users to build models, simulate data from those models (or use them on real data), apply algorithms to the models and graphically display the causal relationships found.
Many features of Tetrad are now supported as Tigris workflow components, making it easier for researchers to do multiple analyses on datasets that may include data from both DataShop and external sources. For example, the following Tetrad support is now available in Tigris:
Following is an example workflow with several of these components. A tab-delimited data file is transformed both to filter missing values and then discretize those values before passing the data to the Search component which searches for causal explanations represented by directed graphs.
Also, two new Analysis components have been added by colleagues at LearnSphere@Memphis. They facilitate analyses of a wider variety of learning sciences data. The new modeling components are TKT (Temporal Knowledge Tracing) and LSA (Latent Semantic Analysis).
Source code for all of the LearnSphere components can be found in our GitHub repository. If you would like to add your analysis, import, transform or visualization component(s) to Tigris, please contact us for information on how to get started.
The last release added 'Request Access' support to workflows, allowing users to request access to data and results in public workflows with shareable data, but it required that all of the data used in the workflow be shareable. Workflows often use multiple data sources, though, so authorization is now enforced per-component. This means that workflows which include both private and shared data can be partially accessed by users. Results and data that are inaccessible show up as 'Locked' components.
In addition to the above Tigris improvements, the following features were added to DataShop: