Extension card · Plithogenic
Plithogenic DNMA
This is the form of DNMA for situations where criterion scores are given as a truth-indeterminacy-falsity triple and criteria carry a degree of contradiction relative to one another. It combines three separate aggregation measures and again produces a single combined score.
Base method
DNMA →
Philosophy, mechanics, strengths and weaknesses are on the base method card; this card describes only the difference.
Data type (family)
Plithogenic →
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?
Four things change.
Cells. In crisp DNMA every cell is a single number. Here every cell is a truth (T), indeterminacy (I), falsity (F) triple. As on the plithogenic data-type card, one criterion is taken as dominant with a contradiction degree of zero; how far each other criterion opposes the dominant one is given by a contradiction degree between 0 and 1. For a cost criterion the triple is first complemented (T,I,F becomes F,I,T), every cell is then adjusted by its own criterion's contradiction degree, and it descends to a single number with the neutrosophic score function ((1+T-2I-F)/2). Crisp DNMA already expects a number; here this score simply takes the place of crisp DNMA's input number.
Two separate normalisations. Crisp DNMA equalises this score in two different ways: linear-maximum (dividing by the column maximum) and vector norm (dividing by the square root of the sum of the squared column values). The plithogenic extension applies the same two normalisations, but to the contradiction-adjusted score rather than the raw number. Linear normalisation always falls between 0 and 1; the vector norm need not.
Combining three measures, and an important limit. This extension's engine computes three measures: u1, the weighted sum of the linear norm; u2, a weighted sum built from the linear norm's complement; and u3, a ratio built with the vector norm. Algebraically, u2 is identical to u1 as long as the weights sum to 1: u2 = 1 − Σw(1−r) = Σw·r = u1. This is a property that comes from pure algebra, independent of the data; it has been verified by this card's author by running the kernel directly (see the verification notes). The consequence is that only two independent signals, not three, actually enter the final score. Furthermore, the rank-consistency penalty that is crisp DNMA's signature step (comparing the three models' rankings and penalising the inconsistent alternative) is absent from this extension's engine; the three measures are combined by a simple average alone (U = (u1+u2+u3)/3).
The contradiction degree's effect is partial and measured. The linear norm (u1, and hence u2) is entirely independent of the contradiction degree, exactly as in P-COCOSO and P-VIKOR; min-max scaling fully absorbs the linear transformation of the form c+(1−c)·s(0) produced by the contradiction adjustment. But the vector norm does not absorb this transformation, because it is not a scaling rule that accommodates an additive shift (the c term). As a result, u3 changes measurably as the contradiction degree rises: in this card's illustrative example, raising the contradiction degrees from 0 to 0.90 shrinks u3's spread across the three alternatives from 0.362 to 0.011, that is, to almost a tenth (see Case 1). The final U score is therefore also affected in a measured way; the finding that the contradiction degree has zero effect, which holds for P-COCOSO and P-VIKOR, does NOT hold in exactly the same way here.
DecisionMind holds the contradiction adjustment, the two normalisations, and the simple average of the three fixed in this extension. Weights come from outside; the method does not generate weights.
How to Read the Output
As in crisp DNMA, the U score is a number summarising how far several measures agree; it can be negative, and it cannot be compared with a different alternative set. But in this extension the claim that "three models confirm one another" is not as strong as in crisp DNMA, because u1 and u2 are already the same number and the rank-consistency penalty is never computed. Furthermore, u3's discriminating power narrows as the contradiction degree rises; in an analysis run with high contradiction degrees, most of the score effectively comes from a single signal (u1 = u2).
Thus instead of writing:
"P-DNMA offers an assurance arising from the consistency of three independent aggregation models, so the result is robust"
the report should read:
"In this engine u1 and u2 are algebraically the same number, and the rank-consistency penalty is not computed; the real discriminating contribution comes from u3, and that weakens as the contradiction degree rises"
When to Prefer This over the Base Method
Consider this extension when your criterion scores are given as truth-indeterminacy-falsity triples and some criteria are a more independent, or more contradictory, source of information than others. But because of the finding above, entering high contradiction degrees only leans further on u3, whose discriminating power is already weak; using the contradiction degrees as a "fine-tuning" tool is misleading. Turning a measured criterion into a T-I-F triple is producing uncertainty, not modelling it; this principle holds here too. The exit condition of crisp DNMA holds here as well: this extension is not suitable if a criterion column is constant or if no compromise is acceptable on one criterion.
Mistakes Specific to This Extension
Presenting the result as "the consensus of three independent models." u1 and u2 are always the same number; this engine effectively has two signals (u1=u2 and u3), not three. The report should say so.
Assuming the rank-consistency penalty is running. The crisp DNMA card describes this penalty as DNMA's signature; there is no such step in this extension's engine, and U is a simple average.
Treating the contradiction degree as a tool for "pulling the result the way I want." The contradiction degree affects the result only through u3, and only indirectly; it is not a direct, predictable lever.
Choosing the dominant criterion arbitrarily. Even though the contradiction degree's effect is partial, which criterion is treated as dominant (zero contradiction) must be stated openly and justified in the report.
Skipping the cost complementation. If the calculation proceeds without rewriting (T,I,F) as (F,I,T) for a cost criterion, the highest-cost alternative appears to have been drawn towards the ideal.
The governing principle is this:
In P-DNMA the number of independent signals feeding the final score is smaller than it appears, and the contradiction degree's effect lies, in a measured way, in only one of them; the report must show both limits together.
Cases
The first case is DecisionMind's validation example; the synthetic 3x3 triple table in the manifest was built faithfully to the formulas and carries no literature page. It was computed by this card's author by running the kernel directly. The second case is an illustrative construction.
1. Illustrative example (DecisionMind's validation example): Choosing an automation software proposal
A manufacturing firm compares three automation software proposals on three criteria: functional fit (more is better), support quality (more is better), and a licence-cost index (less is better). Each proposal is scored on each criterion with a truth-indeterminacy-falsity triple. Functional fit is taken as the dominant criterion with a contradiction degree of zero; the contradiction degrees of support quality and the cost index are 0.33 and 0.67 respectively.
| Proposal | Functional fit | Support quality | Cost index (less is better) |
|---|---|---|---|
| Y1 | (0.70; 0.20; 0.10) | (0.50; 0.30; 0.20) | (0.60; 0.30; 0.20) |
| Y2 | (0.80; 0.10; 0.10) | (0.60; 0.20; 0.20) | (0.40; 0.20; 0.30) |
| Y3 | (0.60; 0.20; 0.20) | (0.70; 0.20; 0.10) | (0.50; 0.30; 0.20) |
| Contradiction degree | 0.00 | 0.33 | 0.67 |
| Weight | 0.40 | 0.35 | 0.25 |
The method complements the cost criterion, adjusts every cell by its own criterion's contradiction degree, and reduces it to a score. It then computes the linear and vector norms, builds u1, u2 and u3, and takes their simple average.
| Proposal | Combined score (U) | Rank |
|---|---|---|
| Y2 | 0.7853 | 1 |
| Y3 | 0.4501 | 2 |
| Y1 | 0.2842 | 3 |
The result reads as follows. Y2 has the highest truth value (0.80) on functional fit, the most heavily weighted criterion, and also the lowest (and so, once complemented, the best) truth value on the cost criterion. Together these carry Y2 clearly into the lead.
The firm's hesitation appears once the contradiction degrees are touched. If all three criteria's contradiction degrees are pulled to 0, the U scores become Y1 = 0.2283, Y2 = 0.8156, Y3 = 0.4264; if all are raised to 0.90, they become Y1 = 0.2975, Y2 = 0.7678, Y3 = 0.4587. The ranking (Y2, Y3, Y1) does not break down at either extreme, but the scores shift measurably. The source of this is u3: as the contradiction degree rises from 0 to 0.90, u3's largest spread across the three proposals falls from 0.362 to 0.011, meaning u3 loses almost all of its discriminating power. u1 and u2, by contrast, are entirely unaffected by the contradiction degree, because they are already the same number and linear normalisation absorbs the linear effect of the contradiction adjustment.
In the report: "With the weights given, Y2 leads clearly (U = 0.7853); this ranking is robust to the contradiction degrees, but the size of the score changes measurably as the contradiction degree rises, because u3's discriminating power narrows. Since u1 and u2 are the same number in this engine, the real discriminating contribution comes from u3."
Source: DecisionMind's P-DNMA validation example. The plithogenic operations (contradiction adjustment, score function) rest on the formulas defined by Smarandache (2018); the aggregation skeleton rests on Liao and Wu's (2020) DNMA method. Neither founding source gives a DNMA decision-table example; the table was constructed by this card's author faithfully to the formulas. The U scores and the contradiction-degree sensitivity test were computed independently by running the kernel directly.
2. Public transport: A municipality's choice of bus-fleet renewal proposal
A municipal transport operator will choose one of three fleet-renewal proposals. There are three criteria: fuel efficiency, passenger comfort score, and delivery time (less is better). The operator treats fuel efficiency as the dominant criterion. It judges that passenger comfort partly contradicts fuel efficiency, because a more comfortable vehicle is heavier and consumes more fuel, while delivery time carries more independent information, and sets the contradiction degrees accordingly. Each proposal is scored on each criterion with a truth-indeterminacy-falsity triple.
The method adjusts the three proposals by their contradiction degrees, applies the two normalisations, computes u1, u2 and u3, and takes their average. Suppose the proposal with the highest fuel efficiency is also the one with the longest delivery time. It still comes out first, because the weight on fuel efficiency exceeds that on delivery time.
The operator's hesitation is this: whatever contradiction degree is assigned to passenger comfort, its contribution to the result in this engine comes not through u1 or u2 but only through u3, and to a limited extent. The operator cannot use this degree as a tool for "pushing comfort further forward"; the real determinant is the criterion weights. Choosing a proposal with a long delivery time can delay the line's opening timetable; this risk is invisible inside the U score and should be bounded by a separate delivery-time threshold.
In the report: "With the high weight given to fuel efficiency, the most efficient proposal ranks first; the contradiction degrees' contribution to this ranking is limited, and the criterion weights are the real determinant. Since the weight on delivery time has been kept low, a separate delivery-time threshold is recommended if the opening timetable is fixed."
3. What Not to Do
Had the cost index been marked "more is better" in the illustrative example, the most expensive proposal would be drawn towards the ideal and the ranking would become meaningless. The second error is trying to "fine-tune" the result by changing the contradiction degrees; in this engine the contradiction degree's effect runs only through u3 and is limited in size, not a direct lever. The third error is presenting the result as "a robust ranking confirmed by three independent models"; in this engine u1 and u2 are the same number, and the rank-consistency penalty is never computed.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/p-dnma
Liao, H., & Wu, X. (2020). DNMA: A double normalization-based multiple aggregation method for multi-expert multi-criteria decision making. Omega, 94, 102058. DOI: 10.1016/j.omega.2019.04.001
Smarandache, F. (2018). Plithogenic Set, an Extension of Crisp, Fuzzy, Intuitionistic Fuzzy, and Neutrosophic Sets – Revisited. Neutrosophic Sets and Systems, 21, 153–166. DOI: 10.5281/zenodo.1408740
Smarandache, F. (2017). Plithogeny, Plithogenic Set, Logic, Probability, and Statistics. Pons Publishing House, Brussels. (no DOI)
Abdel-Basset, M., & Mohamed, R. (2020). A novel plithogenic TOPSIS-CRITIC model for sustainable supply chain risk management. Journal of Cleaner Production, 247, 119586. DOI: 10.1016/j.jclepro.2019.119586