From the PARcore Data Visualization Studio Landing Page, navigate to this report by selecting the Compare Deltas report icon.   This report is only applicable for requests that include the Analysis Type of Item Analysis - Classical and included the optional Compare Deltas analysis.  

The bento box menu icon at the top left of the report can be used to navigate back to the Landing Page.
 




When first launching the report it will be empty.  Make initial filter selections in order to visualize the report.  Any filter with a red asterisk indicates it is required to have a selection made before the report can be displayed.


Filters
Refer to Visualize Results for general information about filter navigation for any report.  The filters for this report are:


 

• Upon first initializing this dashboard, the filter will display as (Choose your analysis) and a selection must be made. 
• Select the search icon (magnifying glass) and enter search text to see Analysis filter options for the request you are viewing.  Using an asterisk in the search text box will display all possible analyses to choose from.  
• Once the current analysis results have been reviewed, continue to use the search feature or utilize the slider arrows (< and >) to view each analysis one at a time.  If there is only one analysis for this report the navigation buttons will be disabled.
• The criterion score for the analysis will also be included in the filter description.

• The default filter selection is None (no confidence bands will display).  If confidence bands are desired, users can select among the options of 1 Standard Deviation, 2 Standard Deviations, 3 Standard Deviations, or 4 Standard Deviations for confidence range.

•  Accession numbers are listed alphabetically. Users can move through the accession number list to select one accession number at a time, or users can enter into the search text box (with the gray font text "Highlight Accession Number) to narrow the selection as needed to find the accession number they want to view.
• When selecting an accession number, it will automatically highlight that item in both plots.  
• To close out of a selected accession number, select the "X" icon in the filter.

• The Delta Equating Graph, which plots the Input Reference Delta values against the Observed Delta values, is displayed on the left side.  

• If confidence bands are selected to display, they will display as dotted lines in the Delta Equating Graph.  Any items that are outside the confidence band will be identified in red.  A subtitle underneath the graph title will also display how many items in the analysis are outside of the confidence band range.  
  • Confidence bands are only produced when there are differences between the output and input reference deltas.  If the Output - Input Reference Delta is 0 for all items, no trend line will appear even if you select to view confidence bands. 

• The Comparison of Input and Output Deltas graph, which plots the Output-Input Reference Delta values against the Input Reference Delta values, is displayed on the right side. 

• A tooltip is available when hovering over a data point in either graph to identify the statistic values.  The tooltip also includes information to identify which item(s) are represented by the data point. 
  • There is a potential for item overlap if more than one item has exactly the same unrounded x and y values.  As a result, a frequency count of how many items are represented by the data point and the list of those items is included in the tooltip. 
    • Data points that represent more than one item (have a frequency count > 1) will be slightly brighter/darker as an additional indication to the user.
  • If the analysis being viewed has multiple assembly units for a single accession number and the processing option of "Combine Response by Accession # Across Forms/AUs" was selected in the requested details, the tooltip will display all of the assembly units for that combined item, but the item is counted as just one single item/data point when determining the frequency count in the tooltip.  
  • There is a limit to how many items can be displayed within one tooltip (approximately 20).  If the number of items overlapping at one data point reaches the tooltip space limit, a message will appear in the tooltip that "View is too large to show" and the user will not be able to see all the items displayed.  If this occurs, refer to the Item Summary dashboard directly to identify all the items with the relevant statistic values.  

• If desired, utilize the zoom feature to expand the plot to get a closer view of a set of data points.  Refer to Visualize Results for general information about zoom functionality.

• Summary statistics for the common items being plotted in the Delta Equating Graph are displayed beneath the plots.   The Number of Items, Cross Product, Correlation, A Parameter and B Parameter are also displayed.