Consensus shows how unanimous the respondents are.
Consensus is calculated by comparing respondents and their answers together and calculating level of agreement between respondents.
For example.
Gender:
1 Male
1 Female
Consensus is 50%. Males agree in general with a degree of (100% + 0%) / 2 = 50% and females agree with degree of (0% + 100%) / 2 = 50%. We have 1 males and 1 females. (2 * 50 + 1 * 50) / 2 = 50%
Gender:
2 Male
1 Female
Consensus is 56%. Males agree in general with a degree of (2 * 100% + 1 * 0%) / 3 = 66.7% and females agree with degree of (2 * 0% + 1 * 100%) / 3 = 33.3%. We have 2 males and 1 females. (2 * 66.7 + 1 * 33.3) / 3 = 56%
Gender:
1 Male
99 Female
Consensus is 56%. Males agree in general with a degree of 1% and females agree with degree of 99%. We have 1 males and 99 females. (1 * 1 + 99 * 99) / 100 = 98%
Will you recommend us (slider from 0 to 10):
1 answer in 0 (for this example, let's name this group as "Extreme detractors")
1 answer in 5 ("Moderate detractors")
1 answer in 10 ("Extreme promoters")
Extreme detractors agree in general with a degree of (100% "Extreme detractors" + 50% "Moderate detractors" + 0% "Extreme promoters) / 3 = 50%
Moderate detractors agree in general with a degree of (50% "Extreme detractors" + 100% "Moderate detractors" + 50% "Extreme promoters) / 3 = 66.7%
Extreme promoters agree in general with a degree of (0% "Extreme detractors" + 50% "Moderate detractors" + 100% "Extreme promoters) / 3 = 50%
Consensus is (1*50 + 1*66.7 + 1 * 50) / 3 = 55.6%
Will you recommend us (slider from 0 to 10):
1 answer in 8 ("Almost promoter")
1 answer in 9 ("Moderate promoter")
4 answer in 10 ("Extreme promoters")
Almost promoter agree in general with a degree of ((1*100 + 1*90 + 4*80) / 6 = 85 %
Moderate promoter agree in general with a degree of ((1*90 + 1*100 + 4*90) / 6 = 91.7 %
Extreme promoters agree in general with a degree of ((1*80 + 1*90 + 4*100) / 6 = 95 %
Consensus is (1*85 + 1*91.7 + 4 * 95) / 6 = 92.8%
Examples above are calculated consensuses for single question. Overall consensus is an average from all questions.
What does consensus tell? Consensus tells the level of agreement in a selected group. 100% consensus means that every respondent has answered with exactly same answers. Consensus nearing 50% tells you that there is large disagreement between respondents.
When doing selections from data you can see from consensus how similar the selected group is otherwise.
Example.
Report application user filters based on "Will you recommend" question so that report contains only "Detractors". Now consensus drops from 85% -> 75%. One knows immediately that the group of detractors is not unanimous and that reasons for not recommending are most likely very different between respondents.
Example.
Report application user filters based on "Will you recommend" question so that report contains only "Detractors". Now consensus raises from 78% -> 92%. One knows immediately that the group of detractors shares similarities and one might be able to find similarities on reasons for not recommending.