Extension card · Intuitionistic
Intuitionistic fuzzy MOORA
IF-MOORA is the form of MOORA that works with intuitionistic fuzzy numbers when criteria are not a measured quantity but a judgement, and the support and rejection degrees of that judgement are known separately. It turns the support-rejection difference into a single number and feeds it into the ratio system.
Base method
MOORA →
Philosophy, mechanics, strengths and weaknesses are on the base method card; this card describes only the difference.
Data type (family)
Intuitionistic →
What this data type is, when to use it, how to write it in a cell: the family's full account is here.
What Changes from the Base Method?
Cells. In crisp MOORA every cell is a single number. Here every cell is a judgement's pair of support (μ) and rejection (ν) degrees; their sum cannot exceed 1, and what remains is hesitancy. DecisionMind takes criterion weights as crisp, single numbers in this extension; the uncertainty is carried only in the cells of the decision matrix.
Scale equalisation. Crisp MOORA divides a cell's value directly by its column's magnitude. IF-MOORA first reduces every cell's support-rejection pair to a single score: the score is support minus rejection (μ − ν), and because this value can range from −1 to 1, it is shifted by adding 1, putting it between 0 and 2. This is not, however, a "defuzzification" of the kind seen in the fuzzy or neutrosophic extensions. The hesitancy margin plays no part here at all; only the difference between support and rejection is used. The shifted score is then normalised exactly as in crisp MOORA, divided by the root of its own column's magnitude.
Score and ratio system. The normalised, shifted scores are weighted; the sum over the "lower is better" criteria is subtracted from the sum over the "higher is better" criteria. This is exactly the same operation as crisp MOORA's ratio system; the only difference is that the input has first been reduced to a support-rejection score.
Result and defuzzification. The score-shifting step is itself the defuzzification, and it happens at MOORA's first step, before cell normalisation, not at the end. This differs from Fuzzy MOORA and N-MOORA, where defuzzification happens at the last step, by averaging; in IF-MOORA the support-rejection pair descends to a single score as early as the first step, and the rest of the calculation proceeds on this score exactly as in crisp MOORA.
DecisionMind fixes, for classical IF-MOORA, the score function μ − ν (the Chen-Tan score) and its calculation at the first step; the hesitancy margin (π = 1 − μ − ν) is not used separately at any step.
How to Read the Output
The output is a net score and a rank, as in crisp MOORA, and it is read the same way. The difference is this. The score rests on the difference between a judgement's support and rejection degrees, and never sees the hesitancy margin, the portion the expert neither supported nor rejected. Two assessments with the same score difference (μ − ν) but different hesitancy margins produce the same result in IF-MOORA. This means a judgement with high hesitancy counts exactly as much as one with low hesitancy.
Thus instead of writing:
"IF-MOORA also took hesitancy into account"
the report should read:
"IF-MOORA took into account only the difference between support and rejection; if this difference is the same, the result is the same even where two assessments' hesitancy margins differ, so criteria with high hesitancy must be flagged separately in the report"
When to Prefer This over the Base Method
Use this extension when criteria come not from a measurement but from a judgement, and the evidence for and against that judgement can be collected separately: board votes, expert support/reservation assessments, the support and dissenting-vote proportions given to a proposition such as "this candidate is suitable". If the expert states only "how suitable" and there is no separate source for the opposing view, that is, if ν would have to be written as 1 − μ, this extension is unnecessary and crisp or fuzzy MOORA is enough. The exit condition is the same as for crisp MOORA: if no compromise is acceptable on one criterion, this extension is also compensatory and will not eliminate anything below a threshold.
Mistakes Specific to This Extension
Violating the value space. Every cell must satisfy μ, ν ∈ [0,1] and μ + ν ≤ 1; a pair whose sum exceeds 1 (a judgement given, say, both strong support and a strong reservation) does not fit this structure and requires a different one, such as Pythagorean fuzzy.
Writing ν as 1 − μ. This zeroes the hesitancy margin and reduces the structure to crisp data, erasing IF-MOORA's one contribution, the principle that support and rejection come from separate sources.
Treating the score difference (μ − ν) as the only indicator and never reporting hesitancy. Two criteria can give the same score even though one, such as (0.90; 0.10), is almost fully decided, and the other, such as (0.50; 0.00), is half hesitant; IF-MOORA treats them identically, but the report must tell the reader about this difference.
Turning a measured score directly into a degree of support. Writing a mark of 70 out of 100 as μ = 0.70 and giving ν = 0.30 puts only the score's complement in place of counter-evidence; rejection must be derived from a separate source, such as a dissenting vote or an adverse report.
The governing principle is this:
IF-MOORA carries only the difference between support and rejection; the hesitancy margin neither enters the calculation nor appears in the report of its own accord, so a criterion with high hesitancy must be noted separately.
Cases
The first case is DecisionMind's validation example: a synthetic 3×3 table built for intuitionistic fuzzy MOORA so that it can be followed by hand, not taken from a book or paper. The second case is an illustrative construction.
1. Illustrative example: Portfolio choice among three projects for an R&D board (DecisionMind's validation example)
An R&D board is assessing three projects on three criteria: technical feasibility and market potential ("higher is better"), and implementation risk ("lower is better"). Each criterion is given as the board members' proportion of support (μ) and rejection (ν) for the judgement "this project meets this criterion".
| Project | Technical feasibility | Market potential | Implementation risk |
|---|---|---|---|
| Project 1 | (0.70; 0.20) | (0.60; 0.30) | (0.40; 0.50) |
| Project 2 | (0.80; 0.10) | (0.50; 0.40) | (0.30; 0.60) |
| Project 3 | (0.50; 0.40) | (0.70; 0.20) | (0.20; 0.70) |
| Direction | higher is better | higher is better | lower is better |
| Weight | 0.40 | 0.35 | 0.25 |
The method takes each cell's support-rejection difference (μ − ν), shifts it by adding 1, normalises it against its column's magnitude, weights it, and subtracts the "lower is better" sum from the "higher is better" sum.
| Project | Net score | Rank |
|---|---|---|
| Project 3 | 0.306 | 1 |
| Project 2 | 0.299 | 2 |
| Project 1 | 0.258 | 3 |
The result reads as follows. Project 3 holds the strongest support on market potential and the lowest reservation on implementation risk (that is, it is best on risk), so it comes first despite having the weakest support on technical feasibility. But the gap against Project 2 is very small (0.306 − 0.299 = 0.007).
The board's hesitation is this: if Project 3's support on market potential were lowered one step, from 0.70 to 0.60, that is, if a single board member changed their mind, the order changes. Project 2 comes first (0.309), Project 3 drops to second (0.287), and Project 1 stays third (0.270). This shows that the gap between first and second place is sensitive to a single board member's opinion.
In the report: "Thanks to its advantage on market potential and implementation risk, Project 3 ranks first with the highest net score (0.306); however, its gap against Project 2 is very small, and a single-step change in its market-potential support turns the order in Project 2's favour."
Source: DecisionMind's IF-MOORA validation example; a synthetic, hand-traceable 3×3 intuitionistic fuzzy table, not taken from a book or paper. The net scores and sensitivity values were independently calculated by this card's author in Python and verified against the internal-audit record in DecisionMind's manifest, matching exactly (Project 3 > Project 2 > Project 1).
2. Energy: Grid investment prioritisation at a distribution company
An electricity distribution company, working with a limited investment budget, will decide which of three grid regions to prioritise. The criteria are fault-frequency-reduction potential and impact on the number of customers served ("higher is better"), and investment risk ("lower is better", that is, uncertainties such as encountering unexpected ground conditions on site or permit delays). The engineering board has given a proportion of support and rejection for these three judgements for each region; support is drawn from field reports, rejection from delay records on past comparable projects.
The method reduces the three regions to the same score, weights them, and arrives at a net score. Suppose the region with the greatest customer impact also carries the highest support on investment risk (that is, it is the riskiest region); thanks to the high weight on customer impact, it still comes first.
The company's hesitation is this: the region ranked first has a high hesitancy margin on its investment-risk judgement, because support is 0.40, rejection is 0.30, and hesitancy is 0.30, since the field team has not yet completed the ground survey. The second-ranked region's risk judgement, by contrast, has low hesitancy (support 0.20, rejection 0.75). The net score does not show this difference; the company should not commit firmly to the first-ranked region before the ground survey is complete.
In the report: "The region with the greatest customer impact ranks first on the net score; however, its investment-risk assessment carries high hesitancy, and the investment should not be finalised before the ground survey is complete."
3. What Not to Do
Writing Project 1's technical-feasibility cell as (0.70; 0.45) instead of (0.70; 0.20), so that the sum exceeds 1, is a violation of the value space; the structure does not fit intuitionistic fuzzy data. The second error is "correcting" Project 2's implementation-risk pair, (0.30; 0.60), to (0.30; 0.70) using the rule ν = 1 − μ; this discards the rejection proportion the board gave separately and zeroes the hesitancy. The third error is ignoring the smallness of the net-score gap (0.007, between 0.306 and 0.299) and reporting "Project 3 is clearly first"; this gap is sensitive to a single board member's change of mind, and the report must say so.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/if-moora
Yazdani, M. (2015). New intuitionistic fuzzy approach with multi-objective optimisation on the basis of ratio analysis method. International Journal of Business and Systems Research, 9(4), 355–370. DOI: 10.1504/IJBSR.2015.072584
Atanassov, K. T. (1986). Intuitionistic fuzzy sets. Fuzzy Sets and Systems, 20(1), 87–96. DOI: 10.1016/S0165-0114(86)80034-3
Chen, S.-M., & Tan, J.-M. (1994). Handling multicriteria fuzzy decision-making problems based on vague set theory. Fuzzy Sets and Systems, 67(2), 163–172. DOI: 10.1016/0165-0114(94)90084-1
Brauers, W. K. M., & Zavadskas, E. K. (2006). The MOORA method and its application to privatization in a transition economy. Control and Cybernetics, 35(2), 445–469. (no DOI)