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Index calculations

An important part of the results in Populum are indexes, which are numbers representing the result, usually quantified on a scale from 0 to 100 (except for eNPS, for which the scale is -100 to +100). A few different index types exist in Populum, all of which are described below.

A “driver” is linked to a specific question, and serves as a heading for the question. For example, the name of the driver can be be “Clarity”, while the question itself may read “Our planning is clear”.

Indexes for individual drivers

For each driver in a survey, an index is calculated based on the respondents’ different answers. For the most common question type – the 4-point smiley scale – the index is calculated as follows:

  1. Each individual answer is first quantified on a scale from 0 to 100 as below:
    • Blue smiley = 100
    • Green smiley = 66,7
    • Yellow smiley = 33,3
    • Red smiley = 0
    • The gray “No opinion” smiley is excluded in the calculations
  2. All quantified answers are then summed up and divided in the total number of answers (excluding “No opinion” answers) to get the index.

In Team A, there are 10 answers in total for a specific survey. The answer distribution for the question “Clarity” is as follows:

  • Blue smiley: 3 answers
  • Green smiley: 3 answers
  • Yellow smiley: 2 answers
  • Red smiley: 1 answer
  • Gray smiley: 1 answer

By quantifying the answers on a scale from 0 to 100 (excluding the gray “No opinion” answer) and then calculating the average of the quantified answers, the index is calculated to 57.

Note that if the question has a different scale (e.g. 5-point), the option weights are changed accordingly. For instance, a 5-point scale has the weights 0 – 25 – 50 – 75 – 100 instead.

Main index

The main index (often called “Barometer index” or similar) is a summarizing index representing the total average result. The main index is obtained by calculating the average index of all drivers included in the main index (the so-called “core drivers“). Which drivers constitute the core drivers are always presented in connection with the main index.


For a specific survey cycle, the result of the 6 core drivers used in Organization X for Team A is as below:

  • Clarity: 67
  • Value: 70
  • Efficiency: 75
  • Community: 80
  • Workload: 65
  • Enthusiasm: 80

The main index is therefore (67 + 70 + 75 + 80 + 65 + 80) / 6 = 73.


Some organizations also use “sub-indexes”, which are indexes comprised of a subset of the drivers included in the survey. Sub-indexes are calculated in the same way as the main index (only using the drivers included in the sub-index). Note that a specific driver can (and often will) be included in both a sub-index and in the main index. Which drivers are included in a specific sub-index are always presented in connection with the sub-index result.


The eNPS (Employee Net Promoter Score) question is answered on a scale of 0 to 10. Each answer is then converted into one of three response groups, as below:

  • 0 – 6 = “Detractors”
  • 7 – 8 = “Passives”
  • 9 – 10 = “Promoters”

The eNPS value is then calculated by subtracting the percentage of Detractors from the percentage of Promoters. This means that the eNPS value can be a negative number – the lowest value possible is -100 (all Detractors) and the maximum value is +100 (all Promoters).


For a specific survey cycle, the result of the eNPS question in Team A is 3, 6, 8, 9, 9, 10 (6 answers in total). This means that there are two Detractors (answers with values 3 and 6), one Passive (answer with value 8) and three Promoters (answers with values 9, 9 and 10). 

By subtracting the percentage of Detractors (2 of 6 = 33%) from the percentage of Promoters (3 of 6 = 50%), the eNPS value is calculated to 17.

Note that the number of “Passives” is only included in the calculation by being included in the total number of answers.

Updated on February 17, 2020

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