Friday, 4 September 2015

DataShop 9.0 released

With the latest release of DataShop, our focus was on fixing bugs and enhancing a few existing features.

• Users can now quickly navigate from problem-specific information in a Learning Curve or Performance Profiler report directly to that problem in the Error Report; an "Error Report" button has been added to the tooltips. The Error Report includes information on the actual values students entered and the feedback received when working on the problem.

  

• In the Performance Profiler, if a secondary KC model is selected, the skills from the secondary model that are present in the problem are included in the problem info tooltip.

  

• If the Additive Factors Model (AFM) or Cross Validation (CV) algorithms fail or cannot be run, the reason is now available to the user as a tooltip. The tooltip is present when hovering over the status in the KC Models table. If you have a follow-up questions, remember that you can always send email to datashop-help.

  

  

• Users can now sort the skills in a particular KC model to indicate learning difficulty. By sorting the KC model skills by intercept and then tagging those for which the slope is below some threshold, users can easily identify skills that may be misspecified and should be split into multiple skills. See the DataShop Tutorial videos on how to change the skills and test the result of that change. This sorting feature is available on the "Model Values" tab of the Learning Curve page.

  

• The Cross Validation calculation was modified to provide more statistically valid results. The new calculation computes an average over 20 runs in determining the root mean squared error (RMSE).

Bug fixes

• The Student-Step Export was updated to print only a single predicted-error-rate value for steps with multiple skills, as the values are always the same.
• The Help pages for the Additive Factors Modeling (AFM) have been updated to indicate that DataShop implements a compensatory sum across all Knowledge Components when there are multiple KCs assigned to a single step.
• The KC Model Import was fixed to ensure that invalid characters cannot be used in the model name not only during initial model import, but also in the dialog box that comes up when a duplicate name is detected.

Wednesday, 2 September 2015

Attention! DataShop downtime for release of v9.0

DataShop is going to be down for 2 hours beginning at 6:00am EST on Friday, September 4, 2015 while our servers are being updated for the new release.

Friday, 29 May 2015

DataShop 8.2 released - several enhancements and bug fixes

With the latest release of DataShop, our focus was on fixing bugs and enhancing several existing features.

• In order to easily see which skills are associated with a problem or step, the Performance Profiler tooltips now include the relevant KCs.

  

  Simlarly, the KC information is now included in the Problem point info tooltips on the Learning Curve page.

  

• Web Services was extended to allow users to import new KC models. This functionality, already available via the UI, lets web service users add new KC models to a dataset, mapping steps to skills.
• To make it easier for researchers to identify a student's last attempt at a step, we have added an 'Is Last Attempt' column to the transaction export. This boolean value is true (1) for the transaction with the maximum 'Attempt At Step' and 'Problem View' for a student and step. This can be useful for grading purposes.
• In order to be more flexible, Custom Fields no longer specify a data type; the values in a Custom Field can be mixed, supporting date, number and string formats in a single Custom Field.

  

  Custom Field string values of up to 65,000 characters are now supported.

• KC Models are now grouped by the number of observations with skills (KCs). Comparisons of models only make sense for those with the same number of observations; the models are now grouped by 'Observations with KCs' before being sorted by the user-specified column.
• Previously, uploaded datasets could not be deleted if they had been accessed by any other user. With this release, if a Project Admin wishes to delete a dataset that they uploaded they will be prompted with a list of users that have accessed the dataset which requires confirmation.
• We relaxed an import restriction requiring all transactions to have a value for all dataset levels defined in the import. This is not required for logged datasets so we have removed the restriction for uploaded datasets.

Bug fixes

• A performance bottleneck in the dataset upload path was removed.
• The Additive Factors Modeling (AFM) code now correctly interprets the Outcome column when the value is "Unknown".
• Fixed a bug where exporting transactions for a sample with a long string in the Custom Field value caused an error.
• Sample to Dataset now limits permission to create a dataset from a sample to DataShop and Project Admins.

Tuesday, 26 May 2015

Attention! DataShop downtime for release of v8.2

DataShop is going to be down for 16 hours beginning at 6:00pm EST on Thursday, May 28, 2015 while our servers are being updated for the new release.