Displaying Possible Correlation Characteristics

Upon running the scanner under the Correlation tab, the Possible Correlation Characteristics area displays the possible correlation that may exist between measurement fields, calculated by the KS6800A software using the Pearson's Correlation test.

The columns that appear in this area are:

  1. Feature Id—Name of the measurement field pairs, which are considered for correlation analysis. The field names that are paired up for comparison are separated by a colon.
  2. Description—Prediction by the KS6800A software of whether or not the field pair in that row is correlated; and if correlated, if it's a positive or a negative correlation. The types of description are:
  • The field <field_name1> appears to be positively correlated with <field_name2>.
  • The field <field_name1> appears to be negatively correlated with <field_name2>.
  1. Score—A value that the KS6800A software derives at, using the absolute value from the Pearson's Correlation test, where any value between 0 to 1 indicates positive or negative correlation. In a positive correlation, as the values in one field increase, the values in the other field increase. Similarly, in negative correlation, as the values in one field increase, the values in the other field decrease. In both cases, any value between 0.7 to 1 indicates a strong correlation; any value between 0.5 and 0.7 indicates a moderate correlation, and anything less than 0.4 is considered a weak or no correlation.

You may view either 5, 10 (default), 25 or 50 rows per page. Use the navigation buttons to view the rows displayed on another page.

To view a graphical analysis of whether a field meets the conditions for correlation or not,

  1. Click the row you wish to analyze.

A page is displayed with two types of charts associated with correlation along with the options at the bottom of the page to consider / ignore the values of the corresponding field pairs when scanning for outliers. You may perform some common functions across all chart types, which are explained in Modifying Display of Charts.
  1. Hover the cursor on the charts to display the corresponding values.
  2. Click the legend info to hide / view part of the plotted chart.
  3. Perform the following in-chart functions:
  1. Download as .png
  2. Zoom
  3. Pan
  4. Zoom in
  5. Zoom out
  6. Reset axes

Let us understand the chart types that are plotted in a correlation analysis within the KS6800A environment:

  • Regression—This chart shows the values of the field plotted on Y-axis, which are correlated with the values of the field plotted on the X-axis, using the linear regression model. Compare the Y-axis values for Predication Interval and Confidence Interval plotted along the line of Best Fit against a given value from the field on X-axis.

  • Residuals—This chart plots the difference between the observed value from the field and the predicted mean value against the same values on the X-axis, which were plotted for Regression analysis.

  1. After analyzing the charts, you may choose one of the following options:
  • For the query Are <field_name1> and <field_name2> correlated?, click the Confirm correlation button so that the KS6800A software considers the field pairs for any correlation outliers.
  • For the option Ignore correlation between <field_name1> and <field_name2> when considering outliers, click the Ignore correlation button so that the KS6800A software ignores the field pairs from consideration for any correlation outliers, even if there may be correlation outliers among the selected pair of fields.

After selecting an option, the display returns to the previous page and the entry for the corresponding appears under Confirmed Correlation Characteristics. For more details, see Displaying Confirmed Correlation Characteristics.

  1. To go back to the previous page without choosing any option, use the back button on your browser window.
  2. To return to the View Data window, click Home on top of the screen.