Correlation Tool

The correlation tool enables you to view the level of correlation (ratio of common documents)  between groups defined in a dataset.  

This tool is designed for concept tracking. For example, you can compare geological areas such as countries and states versus political people such as presidents and terrorists. You can also compare themes to sources, themes to languages, and themes to themes.  

To set up a correlation for a dataset

1. Select a dataset from the Dataset Editor and display it in the Galaxy visualization window.

2. Click Groups to display the Groups window.

3. If you have not defined and saved any groups in a prior session, define at least one group in the dataset.  

4. From the Groups list, select at least one group.
   

5. From the IN-SPIRE main toolbar, click Correlation .  The Correlation window will display correlation bars between the highlighted group or groups as a matrix with the rows and columns initially defined by groups highlighted when the Correlation tool was opened.   
   To change the rows displayed in the matrix, select different groups in the Group window.  The Correlation tool will automatically calculate a new correlation matrix as the highlighted groups change.
   

6. To set up the columns compared in the Correlation window, from the Edit menu, select Choose Rows & Columns.  The Row and Column Selector window will display.
   
   The groups highlighted in the Groups window will display in the Rows (Active Groups) area.  These become the rows in the matrix displayed in the Correlation Tool.

7. You can add to the columns of the matrix by highlighting groups in the Groups area followed by clicking on the up arrow .  This will add the highlighted groups to the Correlated by Columns area.  
   
   Use the up and down arrows by the columns list to order and reorder the columns.

8. Click OK. The Correlation Tool will generate a new matrix based on the groups that are in the Groups area (rows)  and the Correlated by Columns area.  

9. To change the rows (Groups), click the Groups button .  The Groups window will display.  

10. Highlight the groups you want to use as the rows in the correlation.  The new rows will display in the Correlation window.

11. To view the number of documents in each of the correlations, select Show Document Counts from the View menu. The document counts will be displayed as long the individual cells in the matrix are large enough to display them.  The document counts will be on by default.

12. To adjust the cell size to fit in the Correlation window, from the Edit menu, select Optimize Cell size.  Optimize Cell Size will adjust the height and width of the cells in the matrix so that they fit in the Correlation Tool window according to user preferences.

13. To save the correlation you have made, from the Shortcuts menu select Save As.  The Save Shortcut As window will display.  Enter a name for the shortcut and click OK.  The shortcut will display in the list under the Shortcuts menu.  

Viewing Color Valences Based on Group Ratings

Valences are cell colors based on group ratings tied to the group evidence as defined in the Evidence Panel.  These cell colors make up the correlation bar.  From the View menu, select Color by Basic Group Ratings.

Using the evidence settings defined in the Groups Evidence Panel, the Correlation Tool will color the bars according to the amount of evidence.

Viewing Color Valences by Detailed Group Ratings

Valences are cell colors based on group ratings tied to the group evidence as defined in the Evidence Panel.  To display the detailed group ratings, from the View menu, select Color by Detailed Group Ratings.

In the detailed group ratings mode, the evidence bars are centered along the middle of the row.  

The center of the group of documents is marked by a black dashed line.

The valence bars are then broken down into sub-bars.  Each sub-bar represents the number of documents that support or refute your hypotheses, are ambiguous, or are unrated as regards the hypothesis.  The sub-bars are colored based on the valence colors as described in Viewing Color Valences Based on Group Ratings.  The bar is then composed so that the unrated sub-bar is centered and the ambiguous bar is split in half, so that half of it goes above and half below the unrated bar.  The supporting bar is placed at the top of the bar, and the refuting bar is place at the bottom of the bar as shown in the following example.

Hovering the mouse cursor within a correlation bar will bring up a tool tip which will display the number of supporting, ambiguous, unrated, and refuting documents that make up the individual bar.

Using the Time Slicer with the Correlation Tool

When you click the Use Time Slicer arrow button at the bottom of the Correlation window, the tool displays the Time Slicer at the bottom of the Correlation window and the data in the correlation matrix is restricted to the current time slice that is selected.

The Time Slicer and the Correlation Tool are designed to be used together. The underlying functionality is that of one tool with three modes.

1. Time Slicer by itself

2. Correlation tool by itself

3. Time Slicer and Correlation together

If you have the Time Slicer open and you select the Correlation tool from the toolbar, the tool will change to mode C.  If you have the Correlation tool open and you select the Time Slicer tool from the toolbar it also changes to mode C. Mode A displays when Correlation is closed and mode B when Time Slicer is closed. Once in mode C, you can return to mode B by selecting the Use Time Slicer arrow button at the bottom of the Correlation window.

Correlation Tool Selection

Clicking a correlation cell in the correlation matrix makes that cell's members the Current Selection.  The selected cell in the matrix will highlight in green.

Ctl-click a cell to add or remove that cell's documents to the Current Selection.  Ctrl-click acts as a selection toggle.  The cell highlight displays or disappears accordingly.

The green highlight indicates cell members are selected.  Some changes turn off the highlight.  Specific examples:

• When the Current Selections change due to action in some tool other than the Correlation tool (e.g., Galaxy select tool), the Correlation tool highlights disappear.  

• When you open or close the Time Slicer, the Current Selections do not change, but the Correlation tool highlights disappear.

• When you clear selections (in any tool), the cell highlights disappear.

• If you add or remove documents from a group that has a cell highlight, the highlight disappears.

• If the Correlation tool and time slicer are open and you click a cell, the corresponding group members for that time slice are selected and the cell highlights.  If you move to a different time slice, the Current Selections do not change, but the cell highlight should disappear.  

Adding new rows to the correlation tool (by making other groups active) does not change the Current Selection or the cell highlights.

Selecting View menu changes to the correlation tool (such as normalization and group ratings) should not change the Current Selection or cell highlights.

Correlation Toolbar Menus

6/21/05