Extension card · Neutrosophic
Neutrosophic SPOTIS (Abdel-aziem, Mohamed & Abdelhafeez, 2023)
Neutrosophic SPOTIS is the form of SPOTIS that works when criterion values are given neutrosophically, as degrees of truth, indeterminacy and falsity. Every cell is first reduced to a single score, the distance to fixed bounds is computed on this score, and the result again ranks alternatives by a single distance value.
Base method
SPOTIS →
Philosophy, mechanics, strengths and weaknesses are on the base method card; this card describes only the difference.
Data type (family)
Neutrosophic →
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 philosophy of "distance to an ideal built from fixed bounds" does not.
Cells. In crisp SPOTIS every cell is a single number. Here every cell is a degree of truth (T), a degree of indeterminacy (I) and a degree of falsity (F). Criterion weights remain crisp numbers; SPOTIS does not generate weights, it takes them from outside.
Scoring. Crisp SPOTIS works directly with the cell's own number. Here every neutrosophic triple is first reduced to a single score: s = (1 + T − 2I − F) / 2. This score rewards truth, penalises falsity and penalises indeterminacy at double weight. So a cell with "evidence that is missing or contradictory" can end up with a score close to that of a cell with "evidence that is directly negative." Fixed bounds are also defined on this scored scale, not on the triple.
Fixed bounds and scaled distance. As in crisp SPOTIS, a lower and upper bound (now two numbers on this scale) is defined for every criterion, the ideal is built from these bounds (the upper bound for a "higher is better" criterion, the lower bound for a "lower is better" criterion), and the absolute difference between the score and this ideal is divided by the width of the bound interval. This step runs on exactly the same formula as crisp SPOTIS; only the input, the neutrosophic score, differs.
DecisionMind holds the score formula (s = (1+T−2I−F)/2) fixed in Neutrosophic SPOTIS. One critical point belongs to the same family as in Fuzzy SPOTIS: if the fixed bounds (a lower and an upper value on this scored scale) are not given explicitly in the analysis input, DecisionMind automatically builds these bounds from that analysis's own observed lowest and highest score among the alternatives; SPOTIS's "fixed ruler" promise only holds when the bounds are defined externally and with justification.
How to Read the Output
The distance value shows, as in crisp SPOTIS, how far an alternative is from the fixed ideal; a small value is good, a large value is bad.
The difference lies here. This distance is computed after three independent components (T, I, F) have been reduced to a single score, and during this reduction the distinction between "evidence is missing" and "evidence is negative" is largely lost; both push the score down in a similar direction. For this reason the report should state not only the distance value but also, drawn from the raw T-I-F table, whether the difference between two alternatives comes from a lack of evidence or from genuinely negative evidence.
Thus instead of writing:
"According to N-SPOTIS, IPA1 is the best portfolio, with a distance of 0.255"
the report should read:
"IPA1's score is closest to the fixed ideal (distance 0.255); the second- and third-placed portfolios differ by a very small margin (0.471 against 0.479), and this order is sensitive to a small change in the criterion weights"
When to Prefer This over the Base Method
Use this extension when information about a criterion is missing, inconsistent or contradictory, and either the alternative set is expected to change over time, or the same fixed standards will be used repeatedly for comparison. Examples: a new investment option with no track record, or a compliance check carried out at regular intervals against fixed thresholds defined in regulation.
If criteria are measured, or experts do not express a separate indeterminacy share, the base method should be kept. If the table is mixed, that is, some criteria crisp and others neutrosophic, DecisionMind requires a single data type; a measured criterion is embedded as (t, 0, 1−t). The base SPOTIS exit condition applies here in exactly the same way: if the fixed bounds are unknown or disputed, or if no compromise is acceptable on one criterion, the method should not be used.
Mistakes Specific to This Extension
Value-space violation. In every cell, T, I, F ∈ [0,1] and 0 ≤ T+I+F ≤ 3 must hold.
Not supplying the fixed bounds as input. The same mistake as in the fuzzy extension applies here: if the bounds are not given explicitly in the analysis input, DecisionMind silently uses the dataset's own lowest/highest observed score, and SPOTIS's "fixed ruler" promise no longer holds for that analysis. Case 1 below shows exactly this situation.
Changing or skipping the score formula. DecisionMind fixes the formula s = (1+T−2I−F)/2; trying to compare the T,I,F triple directly, without defuzzifying it, against a fixed bound is an operation without a formula and cannot be computed.
Confusing high indeterminacy directly with negative evidence. Because the score formula lowers the value for indeterminacy at double weight, an alternative with "missing evidence" can obtain a score similar to one with "negative evidence"; the report must distinguish between the two.
Reading the distance value backwards. In the SPOTIS family a small distance is good; reading a large distance as "the best" reverses the ranking.
The governing principle is this:
Neutrosophic SPOTIS's "no rank reversal" promise only holds when the fixed bounds are defined explicitly and with justification on this scored scale; if the bounds are automatically built from the dataset, the method has silently moved close to neutrosophic TOPSIS.
Cases
The first case comes from the literature. The decision matrix and criterion directions in Abdel-aziem, Mohamed and Abdelhafeez's (2023) investment-portfolio selection problem are the same as the article's own Table 2 (p. 36). The article states that it derives the weights and fixed bounds from expert evaluations using an "averaging method", but it does not publish these weight and bound values numerically (see the approval notes). The calculation below has therefore been carried out with the default behaviour DecisionMind applies for this gap in information (equal weights, bounds taken from these ten portfolios' own observed scores), and it was computed independently by this card's author. DecisionMind's kernel test only verifies that the **ranking** matches the article, not the absolute distance values. The second case is an illustrative fiction that shows the correct use of fixed bounds.
1. Business: Choosing among ten investment portfolios (Abdel-aziem, Mohamed & Abdelhafeez, 2023)
An investor will decide among ten portfolio options (IPA1–IPA10) on nine criteria; seven of the criteria are "higher is better" (IPC1–IPC6, IPC8), and two are "lower is better" (IPC7, IPC9, for example risk and cost indicators). Every cell is a neutrosophic triple (T, I, F) derived from expert scores.
| Portfolio | IPC1 | IPC2 | IPC3 | IPC4 | IPC5 | IPC6 | IPC7 | IPC8 | IPC9 |
|---|---|---|---|---|---|---|---|---|---|
| IPA1 | (0.724;0.206;0.143) | (0.557;0.214;0.286) | (0.736;0.132;0.276) | (0.715;0.306;0.358) | (0.571;0.109;0.222) | (0.473;0.256;0.242) | (0.644;0.361;0.319) | (0.534;0.368;0.140) | (0.408;0.330;0.403) |
| IPA2 | (0.454;0.156;0.169) | (0.420;0.130;0.314) | (0.695;0.225;0.265) | (0.527;0.315;0.229) | (0.487;0.168;0.291) | (0.744;0.297;0.225) | (0.764;0.374;0.182) | (0.592;0.324;0.496) | (0.767;0.155;0.227) |
| Direction | higher is better | higher is better | higher is better | higher is better | higher is better | higher is better | lower is better | higher is better | lower is better |
(The full matrix has ten rows; IPA1 and IPA2 are shown as examples. The T-I-F values for the remaining eight portfolios are recorded exactly as they appear in the DecisionMind manifest and in the source article's Table 2, p. 36.)
The method reduces every cell to a score with the formula s = (1+T−2I−F)/2, builds every criterion's fixed bound (in this case, since the article does not publish the weight and bound information numerically) from the ten portfolios' own observed lowest/highest score, and sums the scaled distances with equal weight (1/9 for each criterion).
| Portfolio | Distance value | Rank |
|---|---|---|
| IPA1 | 0.255 | 1 |
| IPA3 | 0.471 | 2 |
| IPA10 | 0.479 | 3 |
| IPA8 | 0.483 | 4 |
| IPA4 | 0.513 | 5 |
| IPA2 | 0.536 | 6 |
| IPA5 | 0.556 | 7 |
| IPA7 | 0.565 | 8 |
| IPA6 | 0.640 | 9 |
| IPA9 | 0.654 | 10 |
This ranking matches, exactly, the ranking from the article's own Table 2 result (IPA1 > IPA3 > IPA10 > IPA8 > IPA4 > IPA2 > IPA5 > IPA7 > IPA6 > IPA9). However, the absolute distance value reported by the article (0.490 for IPA1, for example) differs from the value computed here (0.255), because the article's actual weights and fixed bounds have not been published numerically and DecisionMind has fallen back to equal weights and data-derived bounds.
The result can be read as follows. IPA1 is clearly first; the second-, third- and fourth-placed portfolios, IPA3, IPA10 and IPA8, are very close to one another (0.471 – 0.479 – 0.483, a difference of under 0.01).
The investor has a hesitation, precisely at this closeness. If the weight on IPC1 is doubled and the other eight criteria are shrunk proportionately, IPA10 takes second place from IPA3 (IPA10 at 0.471, IPA3 at 0.484), and IPA8 falls from fourth to eighth place (0.535). IPA1 stays first under every scenario.
In the report: "With the source article's decision matrix and criterion directions, the ranking computed with equal weights and this set's own observed bounds matches the article's reported ranking exactly; IPA1 is clearly first. However, because the article does not publish its actual weights and fixed bounds numerically, the very small difference (under 0.01) between the second-, third- and fourth-placed portfolios (IPA3, IPA10, IPA8) is quite sensitive to the criterion weights, and this uncertainty should be stated explicitly in the report."
Source: Abdel-aziem, A. H., Mohamed, H. K., & Abdelhafeez, A. (2023), Table 2, p. 36; the decision matrix and criterion directions are taken exactly from the article. Because the article's reported weight and fixed-bound values are not published numerically (see the approval notes), the distance values above were computed independently in Python by this card's author, using equal weights and a data-derived bound assumption; DecisionMind's kernel test also compares only the ranking (not the absolute values) against the article, and this ranking matches exactly.
2. Local government: Choosing a contractor for a waste-collection tender
A municipality will choose among three contractors for waste collection, and will repeat this comparison in every tender period against fixed minimum/maximum standards defined in regulation. Three criteria are evaluated: "this contractor delivers the service as contracted" (C1, higher is better), "this contractor complies with environmental regulation" (C2, higher is better), and "this contractor has a high complaint rate" (C3, lower is better). The degrees of support, indeterminacy and falsity are derived from past audit reports; the fixed bounds (on the scored scale) are taken from the minimum and maximum standards defined in regulation.
| Contractor | C1: contractual compliance | C2: environmental compliance | C3: complaint risk |
|---|---|---|---|
| Y1 | (0.65;0.20;0.20) | (0.60;0.15;0.20) | (0.30;0.20;0.55) |
| Y2 | (0.55;0.25;0.30) | (0.70;0.10;0.15) | (0.40;0.15;0.40) |
| Y3 | (0.70;0.15;0.15) | (0.50;0.20;0.25) | (0.25;0.25;0.50) |
| Direction | higher is better | higher is better | lower is better |
| Weight | 0.40 | 0.35 | 0.25 |
| Fixed bound (score) | [0.10; 0.90] | [0.15; 0.85] | [0.05; 0.70] |
The method reduces every cell to a score (Y1-C1: 0.525 · Y1-C2: 0.550 · Y1-C3: 0.175 · and similarly for the others), builds the ideal from the fixed bounds set in regulation (the upper bound for C1 and C2, the lower bound for C3), and sums the scaled distances with the weights.
| Contractor | Distance value | Rank |
|---|---|---|
| Y3 | 0.379 | 1 |
| Y1 | 0.386 | 2 |
| Y2 | 0.465 | 3 |
The result can be read as follows. Y3 has the highest score on contractual compliance (0.625) and the lowest score on complaint risk (0.125); its difference from Y1 is very small (0.379 against 0.386). Y2 has the best score on environmental compliance, but its weak score on contractual compliance raises its total distance.
The municipality has a hesitation, precisely at the closeness between Y1 and Y3. If Y1's complaint record worsens, that is, if its T value rises from 0.30 to 0.45 and its score therefore rises from 0.175 to 0.325, Y1's distance rises to 0.472 and it drops to third place, behind Y2 as well; Y3 stays first. In other words, Y1's hold on second place depends on its complaint record not worsening.
In the report: "Under the fixed bounds set in regulation, Y3 is closest to the ideal (distance 0.379); its difference from Y1 is very small (0.386), and Y1 could drop to third place if its complaint record worsens. As long as the fixed bounds are not changed along with the regulation, this comparison can be repeated on the same ruler in future tender periods."
3. What Not to Do
The first error, in the investment example, is ignoring the under-0.01 difference between the second-, third- and fourth-placed portfolios and reporting "IPA3 is clearly second." Because the article does not publish the actual weights, this ranking is fragile and the report must say so.
The second error is presenting DecisionMind's equal-weight default result (distance 0.255) as if it were the article's own Table 2 value (0.490). These are two different calculations; only their rankings match.
The third error, in the local-government example, is ignoring Y1's high F (falsity) value of (0.30;0.20;0.55) on complaint risk and deciding prematurely that "Y1 is the best contractor" by looking only at its contractual-compliance score. The total distance combines all three criteria; it cannot be read from a single one.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/n-spotis
Abdel-aziem, A. H., Mohamed, H. K., & Abdelhafeez, A. (2023). Neutrosophic decision making model for investment portfolios selection and optimizing based on wide variety of investment opportunities and many criteria in market. Neutrosophic Systems with Applications, 6, 32–38. DOI: 10.61356/j.nswa.2023.36
Dezert, J., Tchamova, A., Han, D., & Tacnet, J. M. (2020). The SPOTIS rank reversal free method for multi-criteria decision-making support. In 2020 IEEE 23rd International Conference on Information Fusion (FUSION) (pp. 1–8). IEEE. DOI: 10.23919/FUSION45008.2020.9190347
Smarandache, F. (1998). Neutrosophy: Neutrosophic Probability, Set, and Logic. American Research Press, Rehoboth. (no DOI)
Ye, J. (2014). A multicriteria decision-making method using aggregation operators for simplified neutrosophic sets. Journal of Intelligent & Fuzzy Systems, 26(5), 2459–2466. DOI: 10.3233/IFS-130916