Consensus decision-making or consensus politics is group decision-making processes in which participants develop and decide on proposals with the aim, or requirement, of acceptance by all. The focus on avoiding negative opinion differentiates consensus from unanimity, which requires all participants to positively support a decision.

 

Consensus measurement is the central part of a Delphi survey. To be able to measure group agreement, Surveylet calculates four consensus-related measures: consensus score, choice of consensus, group stability, stability threshold and consensus status.

 

1. Consensus Score

 

 Available Statistics to use to calculate consensus score:

 

The most votes. There are two types of majorities:

1) Absolute Majority: if one choice received more than 50% of all votes, then it has obtained an absolute majority;

2) Simple Majority: occurs when one choice receives more votes than any other choices. The choice of consensus does not necessarily have to earn 50% or more of the votes. A choice can win consensus with just 40%, 30%, or even fewer of the total votes, depending on how many other choices are there to choose from.

 

The middle number; found by ordering all data points and picking out the one in the middle (or if there are two middle numbers, taking the mean of those two numbers).

 

The most frequent number - that is, the number that occurs the highest number of times.

 

The "average" number; found by adding all data points and dividing by the number of data points.

 

Consensus status defined by Interquartile Range (IQR) and Standard Deviation (StDev). IQR is also known as "midspread" or "middle 50%" or "fourth spread" as it gives you the range of the middle half of a data set. The standard deviation is a measure of the amount of variation of the values of a variable about its mean. A low standard deviation indicates that the values tend to be close to the mean of the set, while a high standard deviation indicates that the values are spread out over a wider range. The standard deviation is commonly used in the determination of what constitutes an outlier and what does not. When this option is used the choice of consensus will be determined by the Median, and the strength of consensus (Group Stability) will be determined by the Coefficient of Variation.

 

CONSENSUS IN: Interquartile range  ≤ 1 and standard deviation ≤ 1.5.

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 2 ranges with default range labels "Low/High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring within any given range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 2 ranges with default range labels "Low/High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring in the Highest range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 3 ranges with default range labels "Low/Medium/High" configurable through the RANGE LABEL question/matrix column  settings.

 

When Range Consensus is used, the choices of consensus will be the range with that received the most votes. If given range has received the percentage of votes specified by your Stability Threshold, consensus is established.

 

Example for 3-range consensus with 70% of stability:

If over 70% of people voted for choice 1, 2 or 3, then Range 1 (Low) will be the consensus. If over 70% of people voted for choice 4, 5 or 6, then Range 2 (Medium) will be the consensus. If over 70% of people voted for either choice 7, 8 or 9, then Range 3 (High) will be the consensus. You can speficy Range Labels in your Question or Matrix Column property settings.

 

For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring within any given range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: anything else.

 

Your Likert-scale is divided into 3 ranges with default range labels "Low/Medium/High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring in the Highest range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 3 ranges with default range labels "Low/Medium/High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring as 7 to 9 AND < 15% participants scoring as 1 to 3, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 3 ranges with default range labels "Low/Medium/High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring as 7 to 9 AND < 15% participants scoring as 1 to 3, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: < 15% participants overall scoring as 7 to 9 AND (x)% or more participants scoring as 1 to 3, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

UNDETERMINED: Everything else.

 

Your Likert-scale is divided into 3 ranges with default range labels "Low/Medium/High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (Patient-weighted vote): an outcome is included if (x)% or more of all participants score it as 7 to 9 and less than 15% score it as 1 to 3, or if more than (x)% of the patient group scores it as 7 to 9, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%). 

 

CONSENSUS OUT: An outcome is excluded if 50% or fewer participants in each stakeholder group score it as 7 to 9.

 

UNDETERMINED: Everything else.

 

NOTE: The "Patients" stakeholder group must contain the title "Patient"; otherwise Surveylet will use the first choice in the Stakeholder demographics question.

 

Your Likert-scale is divided into 3 ranges with default range labels "Low/Medium/High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring as 7 to 9 AND < 15% participants scoring as 1 to 3, where (n) is configurable through the Stability Threshold question/matrix column setting (default is 70%). 

 

CONSENSUS OUT: 50% or fewer participants scoring as 7 to 9. 

 

UNDETERMINED: Everything else.

 

NOTE: The 70% value is set by the STABILITY THRESHOLD option therefore can be adjusted.

 

Your Likert-scale is divided into 4 ranges with default range labels "Very Low/Low/High/Very High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring within any given range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%). 

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 4 ranges with default range labels "Very Low/Low/High/Very High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring in the Highest range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 5 ranges with default range labels "Very Low/Low/Neutral/High/Very High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring within any given range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: Everything else.

 

Your Likert-scale is divided into 5 ranges with default range labels "Very Low/Low/Neutral/High/Very High" configurable through the RANGE LABEL question/matrix column  settings. For more information about choice range allocation, click here.

 

CONSENSUS IN: (x)% or more participants overall scoring in the Highest range, where (x) is configurable through the Stability Threshold question/matrix column setting (default is 70%).

 

CONSENSUS OUT: Everything else.

 

You may import your own custom consensus if currently available consensus list does not provide you with the measurement your project require. This is an optional service. Requires Enterprise license.

 

Applications of Consensus Measures

 

Summary of when to use the mean, median and mode Please use the following summary table to know what the best measure of central tendency is with respect to the different types of variable.

 

 

           For information about choice range allocation for Range 2, 3, 4, 5 consensus measures, click here.

 

2. Choice of Consensus

 

For multi-selection questions, the choice of Consensus is calculated and its value is coming from the Consensus Score.  The nearest whole number to the consensus score will be the choice of consensus. E.g. if consensus score is 4.69, the choice of consensus will be the choice that is ranked at position #5 starting with the 1st choice at Rank #1. if consensus score is 3.13, the choice of consensus will be the choice that is ranked at position #3 starting with the 1st choice at Rank #1.

 

 The group stability indicates the strength of consensus, or level of consensus. Basically, how strong the agreement on the choice of consensus between all respondents. Available Statistics to use to calculate Group Stability:

- Coefficient of Variation (recommended for rating scale questions): it measures the deviation from the mean; the closer the responses to the mean, the stronger the group stability. The farther responses are from the mean, the weaker group stability is.

- Percentage (recommended for categorical questions - also known as qualitative questions or attribute questions): the group stability will be the percentage of people that selected the choice of consensus.

 

0-100%. If there is single polar consensus, the stability threshold must be met for consensus to be achieved. Stability threshold value can be anywhere between 0 and 100%, with 100% meaning unanimous agreement.

 

Consensus status value can be Disagreement (Dissent) or Agreement (Consent) or Undecided (Undetermined). These Consensus Status labels can be configured from Survey Settings > Consensus tab. The Consent status requires that a Choice of Consensus is established with a Group Stability that is greater than the Stability Threshold.