Example STD Calculation for Top Mover

Tealeaf® implements the Top Mover calculations that are based on extracting the data points over the rolling window, depending on the several factors.

The calculations are based on:

• Type of mover:
• Configured required dataset for valid rolling window. If the data set includes fewer than four data points, the standard deviation is not computed and is reported as --.
• Calculation mode.

This example shows the differences between daily and hourly movers. These configuration options are assumed:

• Type of mover: Daily and Hourly
• Configured required dataset for valid rolling window: The following are the default minimum and maximum values:
  • Top Movers - Minimum data points for calculations - 4
  • Top Movers - Maximum data points for calculations - 16
• Calculation mode: Same Days

For calculating a valid Daily or Hourly top mover with the preceding configuration options, a minimum of four weeks of data is required.

Suppose that you are calculating a mover of counts for Event A. The counts are summed in the following manner for Daily or Hourly movers in this example:

Day

count

Focus date

sum0

one week ago

sum1

two weeks ago

sum2

three weeks ago

sum3

four weeks ago

sum4

For a Daily mover, the counts are summed over 24-hour periods in the rolling window, while Hourly movers use hourly counts during the rolling window.

The metric STDev_SameDays is computed by using the following formula:

StDev_SameDays = std of (sum1, sum2, sum3, sum4)

The average of those four sums is computed this way:

avg_SameDays = avg of (sum1, sum2, sum3, sum4)

The count mover is then computed with this formula:

countDev_AvgSameDays = (sum0 - avg_SameDays)/StDev_SameDays