Tuesday, 7 November 2017

DataShop 10.0 released!

With this release of DataShop we continue to extend the functionality of Tigris, the LearnSphere 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.

The new Linear Modeling Analysis component uses this feature, allowing users to call the R functions lm, lmer, glm and glmer on a data file of their choice.

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:

  • Data Conversion
  • Classifier
  • Estimator
  • Search
  • Knowledge
  • Graph Editor

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:

  • The Learning Curve Model Values page now includes the 'Number of Unique Steps' and 'Number of Observations' for each skill (KC) in the selected Knowledge Component model.
  • The Web Services API was extended to allow users to query and modify project authorization values.
  • Tigris and DataShop both now support a GitHub login option.