Abstract
Large-scale group decision-making (LSGDM) issues are increasingly prevalent in modern society across various domains. The preference information has emerged as a widely adopted approach to tackle LSGDM problems. However, a significant challenge lies in facilitating consensus among decision-makers (DMs) with diverse backgrounds while considering their hesitation and psychological behavior. Consequently, there is a pressing need to establish a novel model that enables DMs to evaluate alternatives with heterogeneous preference relations (HPRs). To this end, this research presents a new consensus-building method to address LSGDM problems with HPRs. First, a novel approach for solving collective priority weight is introduced based on cosine similarity and prospect theory. In particular, a new cosine similarity measure is defined for HPRs. Subsequently, a consensus index is provided to gauge the consensus level among DMs by considering their psychological behavior and risk attitudes. Further, a consensus-reaching model is developed to address LSGDM with HPRs. Finally, an instance of supplier selection is presented to demonstrate the practicality and efficacy of the proposed method.
Keywords
Introduction
With the increasingly complex decision-making environment, large-scale group decision-making (LSGDM), which involves a mass of decision-makers (DMs), has attracted increasing attention from scholars [9, 47]. As an effective way to express DMs’ opinions, preference relation has been widely used in LSGDM [10, 63]. DMs express their evaluation opinions utilizing a preference relation by comparing the alternatives in pairs, which is a more precise approach than direct assessments. Given the involvement of abundant individuals with diverse knowledge, experience, and professional backgrounds, different forms of preference relations may be utilized. As a result, the application of HPRs in LSGDM has emerged as a significant research topic in recent years [6, 62].
However, there has been limited research in the field of heterogeneous LSGDM that considers the hesitation of DMs. Furthermore, most research in this area has been focused on a single preference structure, such as preference order, utility function, fuzzy preference relation (FPR), linguistic preference relation (LPR), or multiplicative preference relation (MPR). Unfortunately, these structures fail to adequately capture the hesitation and uncertainty that DMs experience in complex decision-making environments. In reality, due to the constraints imposed by their knowledge and experience, DMs often struggle to provide accurate evaluation information, especially when multiple factors need to be considered in complex decision-making problems. FPR and MPR only enable DMs to convey a single degree of preference, which fails to capture the nuanced qualitative evaluation information and accompanying hesitation. Especially for LSGDM problems involving a mass of DMs, if the hesitation of DMs is ignored, the decision results may deviate from the original intention of DMs.
As is known to all, in traditional group decision-making (GDM), various preference relations reflecting DMs’ hesitancy have been deeply studied. The most commonly used ones include hesitant fuzzy linguistic preference relations (HFLPRs) [65], intuitionistic fuzzy preference relations (IFPRs) [35], and interval-valued fuzzy preference relations (IVFPRs) [46]. Among this, HFLPRs can express DMs’ qualitative assessment information along with their hesitancy. IFPRs can gauge DMs’ preference degree from both positive and negative perspectives. Lastly, IVFPRs allow for the expression of DMs’ preference degree within a certain range. These three preference relations comprehensively cover the hesitancy and uncertainty that DMs may exhibit in most scenarios. Thus, this research employs HFLPRs, IFPRs, and IVFPRs to measure DMs’ hesitancy and uncertainty within the LSGDM environment. This is the first point of interest in this research.
Since evaluation opinions are given by DMs subjectively, the psychological behavior and risk attitudes of DMs have a significant influence on decision results. As an effective tool to measure the psychological behavior of DMs, prospect theory has been extensively applied in GDM problems [17, 51]. Nevertheless, the DMs’ psychological behavior is seldom considered in existing heterogeneous LSGDM. Actually, even in complex LSGDM problems involving multiple DMs, the psychological behavior of the DMs still holds significant influence over the decision outcomes. Varied psychological behaviors and attitudes towards risk will result in divergent final evaluation opinions, particularly when DMs demonstrate hesitance and uncertainty during the provision of initial evaluation opinions or in the consensus-reaching process. Additionally, the psychological behavior of DMs during the feedback adjustment phase also affects whether they can accept feedback suggestions. Therefore, this study incorporates prospect theory into heterogeneous LSGDM problems with three distinct preference evaluation forms to align with the psychological behavior of DMs and enhance the accuracy of decision results.
As a crucial component of LSGDM, the consensus-reaching process significantly enhances decision result reliability, making it more widely accepted and recognized by DMs. Currently, the consensus-reaching model in LSGDM has garnered extensive attention [6, 60]. Tian et al. [43] presented an adaptive consensus-building process to detect the non-cooperative behavior of DMs in heterogeneous LSGDM. Tang et al. [41] gave a consensus-reaching method with hybrid strategies by considering the cohesion of subgroups. Liu et al. [20] built a consensus model by detecting and managing the overconfidence behavior of DMs in an LSGDM environment with self-confidence fuzzy preference relations. Chao et al. [6] proposed a consensus-building model by considering non-cooperative behavior and heterogeneous preference structure in LSGDM and applied it to the financial inclusion project. The management method of personalized individual semantics and consensus in linguistic distribution LSGDM was provided by Xiao et al. [55]. Based on the interactive information feedback mechanism, Nie et al. [27] constructed a consensus-reaching process that considered the non-support degree for minority opinions.
In the consensus-reaching process, a consensus measure is a crucial tool for gauging the level of agreement among DMs [30]. Similarity measures are commonly used to assess the degree of consensus since they efficiently obtain the collective priority vector [5, 43]. Accordingly, this paper utilizes the cosine similarity measure to evaluate HPRs’ similarity and effectively assess the level of consensus.
The consensus-building models mentioned above effectively address LSGDM problems in various environments, consequently contributing to the advancement of consensus theory. Nonetheless, the study of heterogeneous LSGDM is still at a nascent stage, and the current methods are subject to certain limitations:
(1) Due to the intricate nature of decision-making problems and the constraints posed by DMs’ knowledge and experience, it is natural for DMs to encounter hesitancy and uncertainty when evaluating alternatives. Various fuzzy sets have been proposed to capture and represent such hesitancy and uncertainty [2, 66]. However, current research on heterogeneous LSGDM inadequately considers DMs’ hesitance. Furthermore, most methods only focus on preference structures with a single membership (such as FPRs and MPRs).
(2) In the LSGDM process, since DMs typically provide subjective decision opinions, the decision results are significantly affected by the psychological behavior and risk attitudes of DMs. Regrettably, current heterogeneous LSGDM methods seldom consider DMs’ psychological behavior and risk attitudes.
Clearly, the existing methods need to be optimized and improved. To this end, this research is dedicated to solving the problem of heterogeneous LSGDM by considering the hesitation, psychological behavior, and risk attitudes of DMs.
With the above discussion, the primary contributions of this article are summarized as follows:
(1) Upon prospect theory, a heterogeneous LSGDM method is proposed that considers the psychological behavior of DMs.
(2) Cosine similarity is employed to measure the consensus level between heterogeneous preference information, which can quickly identify DMs who need adjustment, thereby enhancing consensus efficiency.
(3) A flexible feedback adjustment mechanism is designed, which provides multiple adjustment options for DMs while reflecting their psychological behavior and risk attitude.
The rest of this paper is organized as follows: Section 2 recalls some basic concepts and introduces prospect theory, similarity measure, and three kinds of preference relations (namely, HFLPR, IFPR, and IVFPR). The prospect value function based on three preference relations is defined, and the method for determining the collective priority vector is presented in Section 3. Section 4 establishes the consensus-building model under the heterogeneous preference environment and outlines the general framework. Section 5 provides the application case of the proposed method in supplier selection and offers a comparative analysis. Finally, Section 6 is the concluding remarks.
Preliminaries
To accommodate the uncertain preferences of DMs in various fields, three classic preference relations, namely HFLPR, IFPR, and IVFPR, have been employed to measure the hesitancy of DMs. These three preference relations are highly comprehensive as they encompass three well-established expressions of uncertainty: linguistic, interval value, and intuitionistic. It is noteworthy that this research focuses on decision-making problems in uncertain environments, and the three presented preference relations can readily be expanded to incorporate other forms of preference relations that can effectively represent uncertainty, such as hesitant fuzzy preference relations, probabilistic linguistic preference relations, uncertain linguistic preference relations, etc.
Let X = {x1, x2, ⋯ , x n } indicates the collection of comparison objects throughout the text.
Heterogeneous preference relations
1)
2) |b ij | = |b ji |; 3) b ii = s τ ;
4)
where b
ij
∈ H
s
, b
ij
is the hesitancy degree when x
i
is preferred over x
j
, |b
ij
| is the cardinality of b
ij
, and
The above three preference relations can better reflect DMs’ hesitation and uncertainty and have been widely employed in various decision problems. Kahneman and Tversky [13] proposed the prospect theory to better align with DMs’ original opinions and account for their hesitation and psychological behavior.
Prospect theory
In the research of LSGDM based on preference relation, the cosine similarity measure is often used to solve the priority vector of preference relation due to its good properties. In this study, the cosine similarity measure is adopted to measure the similarity of HPRs and compute the collective priority vector.
Due to the inherent structural differences of HPRs, it is challenging to evaluate the similarity of different preference relations directly. Thus, this research adopts a uniform transformation of HFLPRs and IFPRs into IVFPRs to measure the similarity of HPRs. The conversion methods presented in [49] and [52] are employed as follows:
(1) Let S = {s0, s1, ⋯ , s2τ} be a linguistic term set, then hesitant fuzzy linguistic element h = {s
a
, s
b
, ⋯ , s
c
} can be transformed into interval-valued fuzzy number r = [a/2τ, c/2τ], where 0 ≤ a < b < c ≤ 2τ [49]. Thus, the corresponding HFLPR H = (h
ij
) n×n is converted to IVFPR
(2) Let c
ij
= (u
ij
, v
ij
) is an intuitionistic fuzzy number, then the corresponding isomorphic interval-valued fuzzy number is
After getting the uniform IVFPR, we present the definition of cosine similarity between IVFPRs.

The value functions
The ultimate purpose of LSGDM is to select the best alternative, so a method to address the collective priority vector is presented by adopting the prospect theory and HPRs.
HPRs-based prospect value function
Since both HFLPR and IFPR can be transformed into IVFPR in essence (HFLPR is transformed by the envelope of its hesitant fuzzy linguistic element [32], while IFPR and IVFPR are mathematically and multiplicatively transitivity isomorphisms [52], the specific conversion method is given in Section 2.3), the HPRs are uniformly transformed into IVFPRs and their prospect value (PV) functions are presented in this paper.
To intuitively present the psychological behavior of DMs within the given interval
The figure on the left represents the value function
Note that
An approach for computing the collective priority vector can be acquired by combining the cosine similarity measure with the normalized comprehensive preference matrix of HPRs.
The solution of priority vector
Assume that the preference relations given by each decision-maker are multiplicatively consistent, and there exists a collective priority vector
However, finding a priority vector that fully embodies the preferences of all DMs can be challenging in practical GDM problems. Hence, our goal is to ensure that the value of s (p
j
, w′) approaches 1, ensuring that the individual priority vector closely aligns with the collective priority vector. To this end, an objective programming model is constructed to derive a priority vector that best reflects the individual preferences as follows: max
The value of
This section can be divided into two parts. The first part utilizes the fuzzy C-means algorithm [7] to cluster DMs with similar opinions. The second part delineates the methodology for measuring the consensus level in a heterogeneous preference environment and establishes the consensus-reaching model.
Fuzzy C-means clustering algorithm
Compared with GDM, a significant feature of LSGDM is the large number of DMs involved. Therefore, in LSGDM, DMs should be clustered first to simplify the process of consensus-reaching and improve decision efficiency. At present, many clustering algorithms have been applied to LSGDM [11, 54], among which the K-means algorithm and fuzzy C-means algorithm are the most commonly adopted. Considering that there is a certain similarity among heterogeneous preference opinions of DMs, a preference opinion is allowed to belong to different clusters with different membership degrees. Therefore, based on the similarity measure, the fuzzy C-means algorithm with certain fault tolerance is adopted in this paper. The specific steps are as follows:
(1) Determine the number of clusters: in general, the clustering number N is random and can be determined according to the actual decision-making needs.
(2) Select the initial center point: in order to avoid the sensitivity of the random selection method to the initial center point. This paper uses the average of all expert opinions as the initial center, namely,
(3) Calculate membership degree: FCM algorithm needs to compute membership degree to classify DMs, and its calculation formula is as follows:
(4) Clustering: according to Equation (12), the expert e
k
is assigned as cluster C
h
if R
k
has the maximum membership degree to C
h
, namely
(5) Update centers: take the average of all expert opinions in the corresponding sub-groups
(6) Termination condition: in this paper, with the parameter ξ approaching 0, the termination condition of the algorithm is set as follows
Based on the clustering results of the FCM algorithm, this section presents the consensus-reaching process under the given heterogeneous preference environment, which includes determining the weight of clusters, calculating the consensus degree, and setting up the feedback mechanism.
Determining the weights of clusters and individuals
Through the FCM algorithm introduced above, the population can be clustered into several subgroups, and the opinions of DMs within the subgroup obtained are relatively similar. Therefore, most current researches on the consensus-reaching process regard the subgroup as a whole to discuss the overall consensus level. However, while experts within the subgroup share certain similarities, significant differences still arise when many experts are involved, indicating a comparatively low level of consensus among DMs in the cluster. Thus, Tang et al. [41] proposed a hybrid consensus-reaching strategy by considering intra-subgroup and inter-subgroup consensus levels. Building on this idea, this paper examines the consensus-building process in a heterogeneous preference environment. To achieve this, based on the cosine similarity in Definition 2.6, we present a method for determining expert and subgroup weights.
1) Individual weight: the weight
2) Subgroup weight: Let
Based on individual consensus level, the calculation method of subgroup consensus degree CL
u
can be presented as follows:
Further, the overall consensus degree can be derived as:
Clearly, the values of CL (R k ) , CL u and GCL are all between 0 and 1. If CL (R k ) =1, the individual opinion is consistent with the overall opinion; if CL u = 1, then the subgroup opinion is consistent with the overall opinion, and the subgroup consensus is reached; if GCL = 1, then all the experts’ opinions are completely consistent, and the overall consensus is reached.
Assume that the thresholds corresponding to CL
u
and GCL are
1) If
2) If
Let
According to Definition 3.2, if IVFPR R
k
is multiplicatively consistent, then Equation
1) Monotonicity of
The monotonicity of each function
The monotonicity of each function
With these discussions, the following feedback strategies are offered:
1) If
2) If
3) In the above cases, the decision-maker can flexibly choose to adjust only the value of the left endpoint
In summary, the process of LSGDM with HPRs is given in Table 2.
Prospect theory-based LSGDM method with HFPs
In this section, a numerical example and comparative analysis are given to demonstrate the feasibility and effectiveness of the proposed method.
Numerical example
Prefabricated building is gaining worldwide attention due to their importance in sustainable urbanization [12]. It involves the building products constructed by prefabricating building components, parts, and materials in the factory, transporting them to the construction site, and finally assembling them [37]. Compared with the traditional cast-in-place construction method, the prefabricated construction method has the advantages of shortening the construction period, reducing on-site labor, and improving the quality of the building and life cycle environmental performance. In today’s world, where environmental protection is increasingly importance, the traditional construction methods used in the construction industry are no longer adequate to meet the demands of the industry’s transformation and upgrading. At the same time, prefabricated buildings have become widely used in the construction industry because of the advantages mentioned above [36].
The complete prefabricated building industry chain is based on research and development-design-production-construction-operation and maintenance. As the core node of the supply chain, construction companies have a significant impact on integrating the advantageous resources of each enterprise so that various tasks can be effectively and rationally operated. Therefore, how to select suppliers (e.g., component manufacturing enterprise) reasonably will directly affect whether the prefabricated building project can achieve the expected results.
This section provides an illustrative scenario of supplier selection for a construction company to validate the proposed model. Construction Company B, a general contractor undertaking a prefabricated building project, requires a dependable floor supplier. To ensure an informed decision, Company B invites 20 experts (e1, e2, …, e20) to compare and evaluate five shortlisted companies (x1, x2, x3, x4, and x5) to identify the most suitable floor supplier. The thresholds
Among them, R i (i = 1, 2, …, 6) are the IVFPRs, C i (i = 1, 2, …, 7) denote the IFPRs, and H i (i = 1, 2, …, 7) represent the HFLPRs. The linguistic term set employed here is S = {s0 : extre - mely poor, s1 : very poor, s2 : poor, s3 : slightlypoor, s4 : fair, s5 : slightly good, s6 : good, s7 : very good, s8 : extremely good}.
According to Table 2, the selection process of the supplier is as follows:
Clustering results and weight information
Consensus levels CL (R k ) , CL u and GCL
As listed in Table 4, the overall consensus level is 0.9473, which is below 0.95. Thus, the feedback adjustment process is entered. With CL2 = 0.9426 and CL3 = 0.943, both values are slightly below 0.95. As a result, expert e11 in Subgroup C2 should consider revising their opinions, and experts e14, e15, e16, e17, e18 and e20 in Subgroup C3 should make necessary adjustments to their viewpoints. First, the normalized comprehensive preference matrix
After modification, the consensus level of each subgroup is 0.9565, 0.9545, and 0.9479, respectively, and the overall consensus level GCL is 0.9513. Since 0.9513 > 0.95 meets the acceptable level, even if the subgroup C3 does not reach the acceptable consensus level, there is no need to make any changes. The final collective priority vector is w′ = (0.2053, 0.1891, 0.2293, 0.2073, 0.169), that is, x3 is the best cooperative supplier. As a result, company B should be recommended to choose the third floor supplier under the given evaluation opinion.
Several researchers have proposed various effective solutions for LSGDM problems. This section presents a comparative analysis to illustrate the features and merits of the proposed method.
To ensure a fair comparison, we compare our method (referred to as M1) with that proposed by Wu et al. [53] (referred to as M2), which covers the heterogeneous preference structure utilized in our research. The primary procedures involved in solving the example depicted in Section 5.1 employing M2 are as follows:
According to the classification method in M2, which is based on the type of preference information, DMs can be categorized into three subgroups: C1 : {e1, e2, e3, e4, e5, e6}, C2 : {e7, e8, e9, e10, e11, e12, e13}, and C3 : {e14, e15, e16, e17, e18, e19, e20}. The priority vectors for each subgroup, which have been determined via the utilization of the subgroup score matrix, are listed in Table 5.
Priority vectors derived from M2
Priority vectors derived from M2
Table 5 shows that the initial collective priority vector, weighted by each subgroup’s priority vector, yields (0.2042, 0.2050, 0.1692, 0.1654, 0.2561), indicating that the initial preference order is x5 ≻ x2 ≻ x1 ≻ x3 ≻ x4. Notably, this finding diverges significantly from the initial preference order x3 ≻ x1 ≻ x4 ≻ x2 ≻ x5 obtained in Step 4 of Section 5.1. This can be attributed to the following aspects:
1) Various clustering methods yield distinct clustering outcomes. Unlike the implementation of the fuzzy C-means algorithm in this study, the utilization of classification according to preference information type in M2 results in significant disparities of opinion within the identical subgroup. This discrepancy undermines the representativeness of the aggregated subgroup preference information.
2) Compared with M2, which only utilizes subgroup size as the subgroup weight, this research integrates both subgroup cohesion and size. As a result, the subgroup with a higher internal consensus level is granted a higher weight.
3) In M2, individual preference information is aggregated to obtain subgroup preference information, and subsequently, the priority vector calculated by each subgroup preference information is weighted as the collective priority vector. However, this aggregate process may result in information loss and overlooks the psychological behavior of DMs in uncertain scenarios. Conversely, model (11) is employed in this study to minimize the difference between the obtained collective priority vector and that obtained by each individual, fully considering the psychological behavior of DMs under uncertain circumstances.
In M2, the mean of all individual ordinal consensus levels is treated as the overall consensus level. The corresponding results are presented in Table 6.
Ordinal consensus levels acquired by M2
Upon comparing Tables 4 and 6, it becomes clear that the ordinal consensus levels attained by M2 are substantially lower than that obtained by cosine similarity and prospect theory in this study. Moreover, the overall consensus level B falls far below the consensus threshold of 0.95 prescribed in the above example. The maximum non-full ordinal consensus level with five alternatives that can be achieved is 0.7764 [42]. Thus, relying solely on the ordinal consensus measure is likely to mask the true similarity of distinct preference opinions, resulting in the designated consensus threshold being hard to reach. In contrast, the consensus measurement approach with prospect theory and cosine similarity improves the overall consensus level and reflects the preference intensity for distinct alternatives.
M2 adhered to the principle of minimum deviation and devised a range of goal programming models to provide DMs with modification recommendations in the event of low consensus levels. Nonetheless, due to the stringent constraints of M2, the availability of viable solutions cannot be ensured. If the score matrix obtained in Step 1 is inputted into the M2, a feasible solution cannot be founded. Thus, attaining consensus by utilizing M2 in the above example is unfeasible.
Compared with M2, this paper’s methodology swiftly identifies DMs requiring modifications and corresponding modification locations by utilizing the consensus levels of the three tiers CL
u
, CL (R
k
), and
Also, the disparities with the current methods can be outlined in the following facets:
1) Comparisons of heterogeneous preference environments.
To deal with HPRs provided by DMs, some approaches have been developed [6, 43]. Compared with the preference structures (fuzzy preference relations, multiplicative preference relations, linguistic preference relations, utility functions, and preference orders) studied by Tian et al. [43] and Chao et al. [6], the heterogeneous preference environment used in this paper can extract the decision hesitation information more adequately. For one thing, IVFPRs and HFLPRs can better reflect the uncertainty and hesitation of DMs in complex situations. For another, IFPRs provide DMs with both positive and negative two directions to assess alternatives. In contrast to the heterogeneous information (crisp numbers, interval numbers, triangular fuzzy numbers) examined by Li et al. [14], the heterogeneous information analyzed in this paper offers DMs more flexible assessment options (including both quantitative and qualitative assessments).
2) Comparisons between the proposed method and the existing methods.
Compared to the LSGDM methods in references [6, 62], the proposed method considers the psychological behavior of each decision-maker in the decision-making process based on the prospect theory. Currently, most of the research on LSGDM ignore the impact of DMs’ psychological behavior on decision outcome. Actually, When DMs exhibit hesitation and uncertainty in a complex situation, their psychological behavior significantly impacts the outcome of the decisions [48, 51]. In this study, the interval endpoint values of the assessment information provided by DMs are utilized as two reference points to gauge the potential loss or gain perceived by DMs about their minimum and maximum preferences. The priority weights of alternatives are solved from the comprehensive preference value to obtain the optimal ranking result. Therefore, in complex decision-making scenarios, the results obtained by this method can be readily accepted by DMs.
3) Comparisons of weight determination methods.
Most studies [11, 61] utilized the size of a subgroup as a criterion to determine its weight. In other words, the weight assigned to a subgroup increases proportionally with the number of DMs it encompasses. Moreover, all DMs within the same subgroup are given equal weight. Actually, there may be some differences in expert opinions even within the same subgroup, and the degree of cohesion of different subgroups is not the same [40, 41]. For this reason, Tang et al. [41] considered the two criteria of subgroup size and subgroup cohesion, Ma et al. [23] combined the cluster reliability, and Tang et al. [40] integrated the sum of squared errors in the process of hierarchical consensus-reaching. Compared to methods in references [40, 41], this paper not only considers the size and cohesion of subgroups but also presents an approach for determining individual weight. Taking the weighted average of experts’ preferences as the subgroup center to compute the cohesion of a subgroup is more convincing than directly calculating in references [40, 41].
4) Comparisons of consensus-reaching processes.
Unlike methods in references [11, 41], our approach for calculating consensus degree avoids converging from individual preference to collective one. Therefore, there is no need to discuss the subjective and objective adjustment coefficient [11, 58], and the DMs that need to be modified can be found directly through the feedback regulation mechanism in this paper to give modification suggestions. Compared to feedback adjustment methods in references [6] and [43], this paper presents an adjustment strategy based on the monotony of the function to improve overall consensus levels. This approach reflects DMs’ comprehensive psychological expected value relative to their minimum and maximum preferences in cases of hesitation. Additionally, it offers DMs a more flexible way to modify their opinions by allowing them to adjust either the left or right endpoint according to their preferences, thereby increasing the likelihood of DMs accepting the suggestions. Overall, vis-a-vis the current consensus-reaching models, the features of the proposed model are outlined in Table 7.
Comparison with recent consensus-reaching models
Note. “—” denotes not considered or not involved.
As evident from Table 7, few consensus models simultaneously consider decision makers’ hesitation, heterogeneity, psychological behavior, and risk attitude in both traditional group decision-making [4, 16] and LSGDM [1, 45]. Although Trillo et al. [45] utilized a sentiment analysis approach to detect the degree of positivity and aggressiveness of DMs, there exist fundamental distinctions between their study and the psychological behaviors of DMs in uncertain situations analyzed in this paper. The preference attitude discussed by Tan et al. [38] based on PLPRs differs significantly from the risk attitude in this article. The former is characterized by classifying preferences using linguistic terminology, whereas the latter refers to the subjective inclination of DMs in uncertain situations.
Each method possesses its applicable scenarios. The method proposed in this paper is well-suited for complex decision-making problems where DMs cannot provide precise evaluation information. Additionally, it permits different DMs to adopt varying forms of evaluation information. As different approaches possess their respective advantages in distinct scenarios, this article omits quantitative comparisons with existing methods.
This research presents a novel method to solve heterogeneous LSGDM problems. Firstly, a novel approach is presented for solving the collective priority vector by incorporating prospect theory and cosine similarity between HPRs. For one thing, the hesitancy and heterogeneity of DMs are considered, and the psychological behavior and risk attitude of DMs are reflected. For another, the method aims to ensure the collective priority vector closely aligns with the priority vector obtained by each individual, facilitating consensus building. Then, DMs with HPRs are segregated into multiple subgroups utilizing the fuzzy C-means algorithm, simplifying the calculation process and accelerating the consensus-reaching procedure. Next, the weights of experts and subgroups are determined by utilizing expert confidence degree and subgroup cohesion. This approach effectively distinguishes the importance of varying experts and subgroups. Moreover, three tiers of consensus levels are introduced through cosine similarity, facilitating the rapid identification of DMs who need to adjust. Further, by analyzing the monotonicity of the comprehensive preference value, a flexible feedback adjustment mechanism is designed, which provides multiple options for DMs to adjust. Finally, the effectiveness of the proposed method is verified by numerical examples, and the strengths of the proposed approach are emphasized through comparative analysis.
Admittedly, there are still some limitations that need to be addressed. For instance, the non-cooperative behavior of DMs remains undiscussed, and there may be a certain amount of information loss in the data conversion process. Furthermore, the consistency of preference information following feedback adjustment is not explored. Hence, it is crucial for future research to focus on managing non-cooperative behavior, minimizing information loss, ensuring preference information consistency [59], and extending the application of the proposed method to a broader range of heterogeneous preference environments.
