Extension card · q-Rung Orthopair
q-Rung orthopair WPM
q-Rung orthopair WPM is the form of WPM for situations where an expert assigns a judgement both strong support and a strong reservation at once. The sum of the two exceeds the intuitionistic or Pythagorean bound. Its output is still a single score and the rank that score gives.
Base method
WPM →
Philosophy, mechanics, strengths and weaknesses are on the base method card; this card describes only the difference.
Data type (family)
q-Rung Orthopair →
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?
Three things change. The multiplicative logic does not.
Cells. In crisp WPM every cell is a single, strictly positive number. Here every cell is a pair: support degree μ, rejection degree ν. The sum of the q-th powers of the two degrees cannot exceed 1. The user does not choose q; DecisionMind runs this family at q = 3, this value is fixed, and it is checked at entry. Weights come from outside as crisp numbers.
Scale equalisation. In crisp WPM every column is scaled against its own best value. q-rung cells are already defined between 0 and 1 and on a scale fixed by q itself. No separate scaling step is needed. Instead, the method swaps the support and rejection degree for "less is better" criteria: (μ, ν) becomes (ν, μ). This reversal turns that criterion to face the benefit direction, and the next step proceeds in a single direction.
Weighted product. Crisp WPM's second step raises every column to a power equal to its weight and multiplies. Here this is done with a weighted geometric operator called q-ROFWG: the combined support μ̃ = Πμ_j^{w_j} is a direct weighted product, exactly like crisp WPM itself. The combined rejection, however, is computed as a complementary product over the q-th powers: ν̃ = (1 − Π(1−ν_j^q)^{w_j})^{1/q}. WPM's "weighted product" principle is preserved exactly on the μ side; on the ν side it takes a form that does not break the q-rung constraint.
Result and defuzzification. Once the combined pair (μ̃, ν̃) is obtained, it is reduced to a score by a single score function: S = (1 + μ̃^q − ν̃^q) / 2. Unlike PF-WPM's score of s = μ²−ν², this formula carries a shift. The difference μ̃^q − ν̃^q can range between −1 and 1. Adding 1 and dividing by 2 places the score within 0 and 1 at all times. This shift does not change the ranking, because it is an increasing linear transformation of the difference. It only turns the score, which could otherwise be negative, into a number readable within the 0-1 range. DecisionMind fixes q = 3 and this score function for this family.
How to Read the Output
The score is read as in crisp WPM: it only ranks this alternative set, it is not a percentage or a probability, it is not compared with another analysis. The difference lies here. Even though the score sits between 0 and 1, this does not mean "how many per cent good"; it is only the μ̃^q − ν̃^q difference carried into a readable range.
Thus instead of writing:
"Because the QR-WPM score falls between 0 and 1, it can be read directly as a percentage"
the report should read:
"The score is the difference between support and rejection shifted into the 0-1 range; a value such as 0.60 does not mean 60 per cent suitability, it only marks a ranking position among these alternatives"
When to Prefer This over the Base Method
Use this extension when an expert gives a judgement both strong support and a strong reservation at once, and this pair exceeds both the intuitionistic and the Pythagorean bound. Which pair exceeds which bound is shown by the short decision rule on the q-Rung data-type card. If the pair already fits within the intuitionistic or Pythagorean bound there is no need to raise q; a large q reduces discriminating power, it does not raise accuracy.
Converting an already-measured criterion into this form is wrong. In DecisionMind the table must be of a single type throughout. Crisp WPM's severity continues here. Because μ̃ is a direct product, if μ is close to zero on one criterion, that criterion pulls the combined value down sharply even when its weight is small.
Mistakes Specific to This Extension
Entering data without checking the constraint. In every cell, the sum of the third powers of the support and rejection degrees cannot exceed 1; a cell that fails this is rejected on loading and never enters the calculation.
Confusing q-ROFWG with a simple weighted average. Multiplying μ and ν separately by w_j and summing resembles SAW rather than crisp WPM itself. This can break the q-rung constraint and departs from the method's definition; combination is done only with the product-power formula.
Reversing the cost direction twice. The method swaps the support and rejection degree once for a cost criterion. Repeating this swap after aggregation reverses the direction entirely.
Confusing the shifted score (S) with the raw difference (μ̃^q−ν̃^q) and assigning it a separate meaning. The two give the same ranking, because one is a linear transformation of the other. The shift exists only for readability; a score above 0 does not mean the alternative is "good," nor below 0.5 "bad" — it only shows the order within this alternative set.
The governing principle is this:
In q-rung orthopair WPM, μ̃ carries crisp WPM's weighted product exactly; ν̃ is a complementary product fitted to the q-rung constraint. The final score is this difference shifted into the 0-1 range, not a different computing principle.
Cases
The first case comes from the literature; the figures are taken from a published paper's own table, though the paper published this table not for WPM but for its own method (MABAC). The second case is an illustrative construction.
1. Literature example: Five investment candidates evaluated on four criteria (Wang, Wei, Wei and Wei, 2020)
Wang and colleagues' (2020) paper evaluates five investment candidates (A1-A5) with q-rung orthopair pairs on four criteria (G1, G3, G4 more is better; G2 less is better) in its own Section 6.1 numerical example. It publishes these candidates' q-ROFWG-combined pairs and scores in Tables 2 and 3. The paper uses these figures for its own method, MABAC. DecisionMind uses this table as an anchor, taking advantage of the fact that q-ROFWG combination is the same operation as WPM's weighted product. No independent q-rung WPM paper could be found in the literature (as of the 2026-08-12 search; the one dedicated paper found has since been retracted, see the approval notes). Which concrete investment type each candidate represents remains in the paper's inaccessible full text; this card uses only the published figures.
| Candidate | G1 (μ, ν) | G2 less is better (μ, ν) | G3 (μ, ν) | G4 (μ, ν) |
|---|---|---|---|---|
| A1 | (0.658; 0.4404) | (0.5774; 0.399) | (0.3989; 0.5046) | (0.4794; 0.3086) |
| A2 | (0.7332; 0.3412) | (0.2992; 0.5395) | (0.6314; 0.222) | (0.579; 0.19) |
| A3 | (0.5298; 0.7759) | (0.7988; 0.4124) | (0.4549; 0.4913) | (0.5652; 0.3976) |
| A4 | (0.3801; 0.5146) | (0.6242; 0.3597) | (0.4462; 0.4099) | (0.5074; 0.3984) |
| A5 | (0.7799; 0.5236) | (0.5404; 0.4393) | (0.6326; 0.6641) | (0.4462; 0.4579) |
| Weight | 0.16 | 0.32 | 0.28 | 0.24 |
The method swaps the support and rejection degree in G2, reduces each candidate's pair across the four criteria to a single pair with q-ROFWG (q = 3), and descends to the score S = (1+μ̃³−ν̃³)/2.
| Candidate | Score (S) | Rank |
|---|---|---|
| A2 | 0.5994 | 1 |
| A1 | 0.4858 | 2 |
| A5 | 0.4857 | 3 |
| A4 | 0.4678 | 4 |
| A3 | 0.3959 | 5 |
The result reads as follows. A2 has the lowest raw value on G2, the heaviest criterion (less is better, weight 0.32), meaning the highest support once reversed; this advantage carries the total. A1 and A5's scores sit very close to each other (0.4858 against 0.4857). The paper itself reports that the order of these two candidates differs between a different column of Table 3 (with q-ROFWA, A5-A1) and the q-ROFWG column (A1-A5).
The board's hesitation lies precisely in this closeness. If G1's weight is raised from 0.16 to 0.20 and G2's lowered from 0.32 to 0.28 (G3, G4 held fixed), A5 overtakes A1: A5 = 0.4914, A1 = 0.4909. This was independently verified by running the engine itself in Python. A2 stays first under this change too (0.6032).
In the report: "With the published weights, A2 has the highest score (0.5994). The gap between A1 and A5 is negligible (less than one thousandth); their order reverses once the G1-G2 weight shifts slightly."
Source: Wang, J., Wei, G., Wei, C., & Wei, Y. (2020). MABAC method for multiple attribute group decision making under q-rung orthopair fuzzy environment. Defence Technology, 16(2), 208–216. DOI: 10.1016/j.dt.2019.06.019 (Section 6.1, Tables 2-3). The scores are taken from the paper's own q-ROFWG column; DecisionMind's engine has independently reproduced these figures (within a 1e-3 tolerance).
2. Telecommunications: An operator's choice of 5G infrastructure supplier
A mobile operator will choose one of three 5G infrastructure suppliers (A1, A2, A3) for a network-renewal project. Four criteria apply: coverage performance (more is better), data speed (more is better), supply-chain risk (less is better), total cost of ownership (less is better). The technical board has recorded its support and reservation towards each supplier as a q-rung orthopair pair. On some suppliers both values are jointly very high, because the supplier carries both superior technical performance and a serious geopolitical supply risk.
The method swaps the support and rejection degree on the two cost criteria, combines the four criteria's pairs with q-ROFWG, and scores them. Suppose the supplier with the highest data speed also has (once reversed) the highest support on supply-chain risk, and comes out first.
The operator's hesitation is this: the high support and high rejection pair on the supply-chain-risk criterion shows that the board remains undecided on this point, a matter not yet through an independent audit. The score dissolves this duality internally. The operator should request an independent supply-chain audit report from this supplier before trusting the ranking.
In the report: "One supplier leads on data speed and coverage performance. This supplier's supply-chain-risk criterion shows both high support and high reservation; this tension should be resolved by an independent audit before the contract is signed."
3. What Not to Do
The first error is, in the literature example, disregarding the rejection degree and running crisp WPM on the support degrees alone. In that case A2's score comes out different from its true value and the real closeness between A1 and A5 disappears. The second error is forgetting to swap the support and rejection degree on the G2 criterion; in that case the candidate with the highest raw support on G2, which is in fact the most costly, is the one that stands out. The third error is skipping the S = (1+μ̃³−ν̃³)/2 shift and reporting the raw difference (μ̃³−ν̃³) as a separate "second score"; the two give the same order and need no separate interpretation.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/qr-wpm
Miller, D. W., & Starr, M. K. (1969). Executive Decisions and Operations Research. Prentice-Hall. (no DOI; the founding source for crisp WPM)
Yager, R. R. (2017). Generalized orthopair fuzzy sets. IEEE Transactions on Fuzzy Systems, 25(5), 1222–1230. DOI: 10.1109/TFUZZ.2016.2604005
Liu, P., & Wang, P. (2018). Some q-rung orthopair fuzzy aggregation operators and their applications to multiple-attribute decision making. International Journal of Intelligent Systems, 33(2), 259–280. DOI: 10.1002/int.21927
Wang, J., Wei, G., Wei, C., & Wei, Y. (2020). MABAC method for multiple attribute group decision making under q-rung orthopair fuzzy environment. Defence Technology, 16(2), 208–216. DOI: 10.1016/j.dt.2019.06.019