Abstract
The group decision-making problem usually involves decision makers (DMs) from different professional backgrounds, which leads to a considerable point, that it is the fact that there will be a certain difference in the professional cognition, risk preference and other hidden inherent factors of these DMs to the objective things that need to be evaluated. To improve the reasonability of decision-making, these hidden inherent preference (HIP) of DMs should be determined and eliminated prior to decision making. As a special form of fuzzy set, q-rung orthopair fuzzy numbers (q-ROFNs) is a useful tool to process uncertain information in decision making problems. Hence, under the environment of q-ROFNs, the determination of HIP based on distance from average score is proposed and a risk model is established to eliminate the HIP by analyzing the possible impact. Meanwhile, a dominant function is proposed, which extends the comparison method between q-ROFNs and an integrated decision-making method is provided. Finally, considering the application background of double carbon economy, an example by selecting the best design of electric vehicles charging station (EVCS) is conducted to illustrate the proposed method, and the feasibility and efficiency are verified.
Introduction
Multicriteria group decision making problem (MCG DM), which means a group of decision makers evaluate a set of alternatives according to their own preferences, in order to seek the optimal alternative or the ordering of alternatives. Over the past few decades, the MCGDM has attracted considerable attention and has been extensively studied by researchers. Various methods have been developed in different situations, such as the preference ranking organization method for enrichment evaluations (PROMETHEE) method [3,4, 3,4], the evaluation based on distance from average solution (EDAS) method [5] and the novel integrated improved fuzzy stepwise weight assessment ratio analysis (IMF SWARA) method [35].
With the increasing complexity of the situation needed to process in MCGDM, most information becomes imprecise and fuzzy, which leads to many uncertain issues. Therefore, Zadeh [6] proposed fuzzy set (FS) theory in 1965. By establishing appropriate membership degree functions, FS takes the object to be investigated and its membership degree(MD) as a certain fuzzy set, and analyzes the fuzzy object through the relevant operations and transformations. As an effective tool, FS have been widely studied [1, 32]. However, when the information we faced is in the form of MD and non-membership degree (NMD), then there will be some limitations in the application of FS in real life. Thus, it has become popular to present these information by multi-valued sets. Atanssov proposed the concept of intuitionistic fuzzy sets (IFSs) [7] in 1986, which describes the fuzziness using MD and NMD, where the sum of MD and NMD is between 0 and 1. Further, to deal with the more general case, Yager [8] changed the constraints of IFSs to that the sum of their squares of MD and NMD is between 0 and 1 and proposed a new model called Pythagorean fuzzy sets (PFSs). More recently years, Yager [9] introduced a general class of IFSs and PFSs called q-rung orthopair fuzzy sets (q-ROFSs) in which the sum of the qth power of MD and the qth power of NMD is limited to [0,1], which provides a wider range of MD and NMD. Obviously, IFSs, and PFSs are special issues of q-ROFSs.
As an effective tool, q-ROFSs have outstanding capability to solve MCGDM problems, which have attracted considerable attention of scholars [10–12, 19] and have been widely applied in recent years. At present, the research on q-ROFSs mainly focuses on decision making [13, 24–28]; the extended definition of q-ROFNs [14–18, 33] and aggregation operator-based methods [20–22, 34].
As mentioned at the beginning, the same decision-making problem involves DMs from different professional backgrounds. This leads to a considerable point, that it is the fact that there will be a certain difference in the professional cognition, risk preference and other hidden inherent factors of these DMs to the objective things that need to be evaluated. For example, in the given decision-making information, the evaluation of decision maker A is obviously higher than the average evaluation information, while that of decision maker B is obviously lower than the average evaluation information. There is no doubt that the optimistic attitude of A and the pessimistic attitude of B will lead to evaluations being better or worse than their actual level, which may have a certain influence on the rationality of the decision.
To solve the above problem, Li [23] proposed the concept personalized individual semantics(PIS) to reduce the impact of this risk on language terms in 2017. A few years later, these factors that could lead to the deterioration of information or lead to the improvement of information are considered a specific risk and these risk are further modeled by analyzing the possible sources of bias [30, 31]. In addition, in 2022, Chen [36] proposed a novel confidence-consensus model to manage these possible risk preference arising from different backgrounds. Nevertheless, the determination and quantification of such risks are not proposed. Therefore, determining and eliminating the risks that may be brought about by the inherent preferences of DMs is the focus of this paper. Based on the above introduction, the primary motivations of this paper are as follows: With the increase of social demands, more and more individuals can participate in the q-ROFNs MCGDM process. However, due to different experience and psychological cognition of decision-makers, the hidden inherent preferences (HIP) of them are obviously different. Therefore, it is necessary to determine HIP before making decisions. For this reason, the determination of HIP based on distance from average score is proposed. Compared with the subjective given preference, the proposed method extracts the preference from initial objective evaluation information of DMs, which is more reasonable. Different HIP of DMs corresponds to the different evaluation attitude of them. More deeply, optimistic or pessimistic evaluation attitude will lead the evaluations being better or worse than their actual level. Thus, MD and NMD of q-ROFNs are modeled under different types of criteria by analyzing the possible impact. Real-life information is full of uncertainty, which makes decision making problem difficult, while q-ROFNs can solve this problem. However, at present, the comparison methods of q-ROFNs is mainly through distance and score function, while there are few studies on the dominance relationship of q-ROFNs. Hence, the dominant relation between q-ROFNs is proposed to extend the comparison method of q-ROFNs and the PROMETHEE method with q-ROFSs based on dominant relation is provided.
The remainder of the paper is organized as follows: In Section 2, some definitions are briefly reviewed. In Section 3, a novel score function is introduced and some basic properties are proofed. In Section 4, the methods for determining and eliminating inherent perference is introduced. In Section 5, an extended decision-making method is introduced. In Section 6, the method introduced in Section 5 is applied to multi-criteria group decision making problems and in Section 7 the feasibility of the method are discussed. In Section 8, some remarkable conclusions are drawn.
Preliminaries
In this section, some related concepts are briefly reviewed.
(a): H α1 < H α2, α1 ≺ α2
(b): H α1 = H α2, α1 = α2
As an important tool to measure the superiority and inferiority of q-ROFN information, the traditional score functions have limitations in dealing with some special cases. Therefore, in this section, a novel score function is introduced.
Before putting forward the definition of rigorous score function, the limitations of previous score function are briefly reviewed.
As an effective tool to represent uncertainty information, one of the concerns of q-ROFN is the degree of hesitation, which represents the unknown degree of membership and non-membership; another point of concern is the q value, different q values reflect different domain ranges. However, the above score functions do not reflect the variation tendency with the changing of hesitation degree. Based on the above analysis, the definition of q-ROFN rigorous score function is given below.
(P1): 0 ≤ S q (α) ≤ 1
(P2): S q (α) = 0 if and only if α =(0, 1)
(P3): S q (α) = 1 if and only if α =(1, 0)
(P4): S q (α) increases with respect to μ α and decreases with respect to v α.
(P5): S q (α) = S q (β) if and only if μ α = μ β, v α = v β
(P6): S q (α) = S p (α) ⇔ p = q
In the above definition, P5 ensures that under the same q value, only the membership degree and the non-membership degree are all the same, the value of the score function is equal; P6 guarantees that under the same numerical expression, only the q value is the same, the value of score function is equal. In fact, this is a strengthened restriction on hesitation degree, which better embodies the characteristics of q-ROFN information
According to definition 6, a rigorous score function of q-ROFN is given below. Let α =(μ, v) be a q-ROFN, a novel score function of α is defined as follows:
(P1) : According to the definition of q-ROFN, it can be easily found that μ
q
, μ
q
∈ [0, 1], then
(P5): Denote β =(s, t) be a q-ROFN, then S
q
(α) = S
q
(β) is equivalent to
(i): The two numerical results are equal, in this case
(ii): The two numerical results are not equal, in this case, there must be one range in
(P6):S
q
(α) = S
p
(α) is equivalent to
Likewise, there are two cases are considered:
(i): The two numerical results are equal,in this case
(ii): One range in
Based on the above analysis, S q (α) is a rigorous score function and the comparison of counterexamples in Example 3.1 and Example 3.2 under different score functions can be obtained in the following table:
As can be seen from the results in Table 1, considering the potential differences that may be caused by hesitation, the rigorous score function proposed in this paper overcomes the limitation that the hesitation degree changes while the score function does not change. More intuitively, suppose that q = 3, then the variation tendency of S q (α) with the changing of μ and v is shown in Fig
The comparison of different score functions

Variation tendency of the proposed score function with the changing of μ and v when q = 3.
In multi-criteria group decision making (MCGDM) problem, different decision makers (DMs) have subjective evaluations for the same objective result, which may lead to evaluations being better or worse than their actual level. Hence,to improve the reasonability and validity of decision making, it is necessary to identify and address this hidden inherent preferences (HIP) of decision makers. In this section, the composition of HIP is introduced and then the determination and elimination of HIP under q-ROFS environment are proposed.
Problem description
Suppose X ={ x1, x2, …, x
n
} is the set of alternatives, DM ={ d1, d2, …, d
p
} is the set of decision makers and C ={ c1, c2, …, c
n
} are the criteria set to be evaluated. DMs give their own evaluations based on their own perceptions and the decision matrix is written as:
In fact, HIP reflects the positive or negative attitudes of decision makers towards different alternatives and criteria, which may be caused by different behavioral preferences, psychological cognition and other uncertain hidden factors. That’s why it’s called hidden preference. This special preference is reflected in the initial evaluation information, therefore, the determination and elimination of HIP need to be a priority.
Inspired by EDAS method, the HIP should be corresponded to the average score matrix (AVS) of all DMs, the degree that was above the AVS was regarded as the relatively positive attitude while the degree that was below the AVS was regarded as the relatively pessimistic attitude. Then the following concepts are introduced.
The above definition 8-10 is progressive, in which definition 8 merges the evaluations of all DMs into a reference average score matrix, and definition 9 actually obtains the degree of exceeding or falling below this average score matrix, the definition 10 obtains HIP of different alternatives and different criteria by horizontal and vertical processing of the matrix in definition 9.
The positive and negative values of HIP indicate that the current evaluation information is better or worse than the real information. In other words, the degree of preference can be defined as the deviation between the precise value and the obtained value, which can be described as follows [37]:
More deeply, for a q-ROFN (μ, v), assume (μ*, v*) is the exact value (without preference). Then r is expressed as the deviation degree between μ and μ*, v and v*. More intuitively, the deviation caused by different preference is shown in Figure 2

The deviation caused by diffenent pererence.
Therefore, how to measure this deviation is a problem worth considering. In addition, as an important information of q-ROFN, hesitation degree should be potentially correlated with hesitation about membership and non-membership. For example: Let α =(0.3, 0.5) , β =(0.5, 0.3), even if π α = π β, the information in them are different. In other words, if α and β are converted to a crisp set, π α would allocate more membership to α while π β would allocate more non-membership to β. Based on the above analysis, the following definition is given:
where
Let (μ, v) represents decision maker DM k ′s evaluation of alternative x i under criterion c j ,PC j k and PA i k represent DM k ′s preference on criteria c j and alternative x i respectively, if we model PA and PC of the beneficial criterion, the following cases can be considered.
(AN - b): If PA
i
k
< 0, for the beneficial criterion, PA will make the current evaluation information be worse than the real information. the current membership degree will be worse than the real: μA-Nb and the current non-membership degree will be better than the real: vA-Nb, from Eq. (9), we can get
Now, if we model PA of non-beneficial criterion, then the following formula can be obtained:
(AP - c):If PA
i
k
> 0, for the non-beneficial criterion, PA will make the current membership degree will be worse than the real: μA-Pc and the current non-membership degree will be better than the real: vA-Pc, from Eq. (9),we obtain:
(AN - c):If PA
i
k
< 0, for the non-beneficial criterion, PA will make the current membership degree will be better than the real: μA-Pb and the current non-membership degree will be worse than the real: vA-Pb, from Eq. (9),we obtain:
for the non-beneficial criterion,
Based on the above discussion, if PA and PC are both analyzed, for the beneficial criterion, the preference elimination q-ROFN will be:
for the non-beneficial criterion, the preference elimination q-ROFN will be:
The dominant function of q-ROFN
At present, the comparison between q-ROFNs is mainly through distance and score function, while there are few studies on the relationship of dominance. Therefore, this section proposes the dominance measure of q-ROFN.
(1)0 ≤ P(α ≥ β) ≤ 1
(2) P(α ≥ α) = 0.5
(3) P(α ≥ β) + P(β ≥ α) = 1
(1): it can be easily found that
In decision-making problems, a greater contribution to the distinguishing alternatives should correspond to a greater weight. Therefore, combined with the definition of dominance function, the following weight determination formulas are constructed.
Summarizing the results above, we come up with a novel method that can be applied to MCGDM under q-ROFNs environment, where the information about the weights is unknown completely. The decision making procedure can be established as follows

The procedure of proposed method.
(1) x i ≻ x j if φ(x i ) > φ(x j )
(2) x i = x j if φ(x i ) = φ(x j )
In the proposed method, Step1-3 are equivalent to pre-processing the data in advance, including the determination and elimination of hidden inherent preference, Step4-7 is the subsequent decision-making process, which calculates the total dominance degree of each alternative and determine the final partial order relation. Particularly, if the decision-making process is started directly from Step 4, the ranking result without eliminating preferences will be obtained. The procedure of proposed method are shown in Figure 3 fig:decision-making-procdure.
With the rapid progress of science and technology, problems such as energy shortage and environmental pollution are gradually intensifying. In order to achieve carbon reduction goals, the new energy vehicle market has developed rapidly. Nevertheless, as an important component of new energy vehicles, the development speed of electric vehicles (EV)is limited by charging facilities and other supporting facilities. Nowadays, the problems of electric vehicles charging station (EVCS) are mainly reflected in poor efficiency, inconvenient settlement, poor compatibility and serious impact by bad weather. Therefore, the design of charging station is particularly important.
To determine an optimal EVCS, there are five alternatives denoted as X ={ x1, x2, x3, x4, x5 }, four criteria denoted as C ={ c1, c2, c3, c4 }, where c1 refers to total compatibility volume of available motorcycle type, c2 refers to charging efficiency, c3 refers to the transaction settlement convenience and c4 refers to the security. Through a questionnaire, we collect three experts D ={ d1, d2, d3 } to give their opinions about the five alternatives in terms of these four criteria by q-ROFN. What’s more, the weight vector are completely unknown.
The inflow, outfolw and net flow of five altermatives
The inflow, outfolw and net flow of five altermatives
To demonstrate the feasibility of the proposed method, below we perform some comparative analyses with the some existing methods and the proposed method. In order to reduce the uncertain influence of variables on the results, the criteria weight and expert weight is still the weight obtained in this paper.
Compared with the q-ROFWA aggregation operator-based method
The ranking results by q-ROFWA operator is x2 ≻ x5 ≻ x1 ≻ x4 ≻ x3
Compared with the fuzzy MABAC method
The MABAC model is an useful method, which uses a border approximation area (BAA) and then calculate the distance between each alternative and the BAA to get each alternative’s sum value. Below we use q-rung orthopair fuzzy MABAC model [28] to solve the above case.
The comprehensive evaluation information of DMs
The comprehensive evaluation information of DMs
The weighted comprehensive matrix
The distance between WCM and the BAA
According to the above comparison, it can be easily find that the three methods have the same optimal ranking results, which shows the feasibility of the proposed method. In addition, compared with the proposed method, it can be seen that the ranking results of aggregation operator-based method is less discriminative. Although the fuzzy MABAC method overcomes the problem of low discrimination, its calculation is more complicated and it requires the weight of the criterion to be consistent, that is the criteria weight is the same for each expert by default, which does not necessarily correspond to reality. However, numerous studies have shown that the operation of the PROMETHEE method is easy and convenient which just requires the criterion value of each project and weight vector of criteria. Different DMs are considered to have different criteria weights in this paper. therefore, PROMETHEE method is a better choice to get the ranking results.
In order to further explore the impact of the value of q on the decision results, according to our proposed method, we can obtain the ranking relation of the five alternatives when q get other values. The results are presented in Figure 4.

Ranking results of alternatives when q ∈ [1, 10].
It can be easily find that with the change of q values, the ranking of the alternatives has also changed slightly, but x3 and x4 are always ranked behind, what’s more, it is noted that the best alternative is still x2 when q ≥ 3, which shows the robustness of the proposed method.
To manifest the necessity of preference elimination, for different q values, the ranking results obtained by the complete decision procedure are compared with those obtained by deleting Step 2 and Step 3, the results are shown in the following table.

Ranking comparison of before and after perferenceelimination.
Ranking results before and after preference elimination
The q-ROFN decision matrix provided by d1
The q-ROFN decision matrix provided by d2
The q-ROFN decision matrix provided by d3
the hidden preference vector of each DM
Preference elimination for d1
Preference elimination for d2
Preference elimination for d3
i
, i = 1, 2, . . , 5 are obtained
With the development of technology and the increase of social demands, more and more individuals can participate in the decision-making process, which puts forward higher requirements for the accuracy of evaluation information. However, due to different experience and psychological cognition of decision-makers, the HIP of evaluation information is obviously different. Therefore, to improve the reasonability of decision-making, under the environment of q-ROFNs, this paper first introduces a rigorous score function to be prepared for the subsequent determination of HIP. Then based on the rigorous score function, some progressive concepts are proposed, including AVS, PSA, NSA, which make sure that the determination and quantification of HIP is reasonable. Furthermore, a risk model is established to eliminate the HIP by analyzing the possible impact. Finally, we combined the PROMETHEE method with q-ROFNs and applied the new PROMETHEE method to a practical decision-making problem to indicate the validity of the proposed method.
In decision problems, information can be influenced by potential risk factors and leads to deviation, to describe associated risk with the fuzzy data, some concepts like R-numbers[30] and R-Sets[31] are proposed. However, these models give risk values subjectively, which leads to a great deal of subjectivity. Compared with these existing methods, in this paper, all the risks that could lead to deviations are aggregated into HIP and HIP is determinated from the initial evaluation, which ensures the objectivity of the extraction. More deeply, this is a preprocessing process on the initial data, which leads to a more reasonable information. What’s more, the decision results we obtained are based on the dominant relation between q-ROFNs, which will reduce more uncertainties compared with the traditional aggregation operators. Hence, the method proposed in this paper has a great applicability.
The main contributions of the study can be summarized as three points. Some progressive concepts are proposed based on a novel rigorous score function to determine the HIP. To improve the reasonability and validity of decision results, HIP is determined and eliminated by a risk model. We introduce the dominant relation between q-ROFNs to provide a novel PROMETHEE method with q-ROFSs.
Footnotes
Acknowledgment
The authors are highly thankful to any anonymous referee for their careful reading and insightful comments, their constructive opinions and suggestions will generate an improved version of this article. The work is supported by the National Nature Science Foundation of China (No.72171002, No.61806001) and the Project of Graduate Academic Innovation of Anhui University.
