1 Introduction
In reality, because of the intricate nature of the socio-economic landscape and the uncertainty of human thought processes, DMs frequently utilize linguistic expressions to convey the assessment information of various attributes (Diao
et al.,
2022; Tang
et al.,
2022; Wang
et al.,
2024; Zhang, S.Q.
et al.,
2021; Zhao
et al.,
2021; Zuo
et al.,
2020). Therefore, Zadeh (
1974) proposed fuzzy linguistic sets to describe qualitative evaluation information, but more often than not, DMs also use several linguistic terms to express the evaluation information of attributes (for example, when evaluating an artwork, an appreciator may use both “good” and “very good” to evaluate it). Inspired by the hesitant fuzzy set (Torra,
2010) and the linguistic term set (LTS) (Xu,
2004), Rodriguez
et al. (
2012) introduced the hesitant fuzzy linguistic term set (HFLTS). While the HFLTS is capable of conveying much of the evaluation information related to DM, it has two main drawbacks: firstly, the evaluation linguistic used by HFLTS is overly simplistic and the evaluation information is too generalized. Secondly, HFLTS fails to capture the significance of each hesitant fuzzy linguistic component. To compensate for its shortcomings, Gou
et al. (
2017) and Pang
et al. (
2016) proposed double hierarchy linguistic term set (DHLTS) and probabilistic linguistic term set (PLTS). Gou
et al. (
2021) later integrated the benefits of both approaches and introduced the PDHLTS. It consisted of multiple DHLTSs and corresponding probabilities. Its linguistic expression of “adverb+adjective” not only delicately described attribute evaluation information, but also conformed to people’s expression habits. In addition, the probability associated with it can more deeply express the DM’s preference information. Therefore, PDHLTS was more suitable for information expression in practical decision-making processes and was currently an important tool for dealing with MADM problems. Based on it, Gou
et al. (
2017) were the first to define PDHLTS along with its scoring function and distance metric. Furthermore, they adapted the traditional VIKOR approach for the PDHL context and introduced a PDHL-VIKOR method to address a real-world MADM issue related to intelligent healthcare. Subsequently, Lei
et al. (
2021) introduced a novel PDHLTS distance measure, which encompasses both Euclidean and Hamming distance measures, along with a new probability completion method. Furthermore, they integrated the prospect theory (Kahneman and Tversky,
1979) with CODAS method, extending a new distance measurement formula to the PDHL environment to construct a MADM model that can reflect DMs’ loss aversion psychology. The research on the expected function, score function, and distance measurement formula of PDHLTS by the two scholars mentioned above lays the foundation for identifying more classical methods to solve MADM problems in the PDHL environment in the future. For example, Wang (
2022) proposed the PDHL-TOPSIS method and applied it to evaluate the teaching level of a teacher. Liu, P.
et al. (
2023a) combined WASPAS method with weight determination method and extended it to PDHLTSs environment to solve the risk assessment problem in PDHL environment.
In order to scientifically and effectively solve MADM problems, DMs need to choose appropriate decision information measurement tools and construct scientific and efficient MADM methods. The TODIM method proposed by Gomes and Lima (
1991) in 2009 is a validated and effective approach for handling MADM. This method measures the degree of advantage of each alternative solution relative to other alternative solutions by using the overall value, and then evaluates and ranks the alternative solutions based on their overall advantage. In addition, compared with other classic MADM methods (FOR example: TOPSIS method (Hwang and Yoon,
1981), GRA method (Deng,
1989), SWARA method (Zavadskas
et al.,
2012), EDAS method (Keshavarz Ghorabaee
et al.,
2015), MABAC method (Pamucar and Cirovic,
2015), etc.), only the TODIM method is unique in that it takes into account the psychological factors affecting DMs, marking a significant advancement in addressing irrational behaviour in uncertain situations. Therefore, it has been applied in many fields (Hong
et al.,
2019; Liu and Teng,
2015; Wei and Wu,
2019; Zhang
et al.,
2017; Zindani
et al.,
2020) and has achieved significant results. Among them, Zhang
et al. (
2019) applied the improved intuitionistic fuzzy set (IFS) score function and exact function to the TODIM method, and constructed an IF-TODIM model for evaluating supplier production capacity while comparing the differences between IFSs. Sun
et al. (
2019) extended the classic TODIM method to interval IFSs and constructed a new MADM model, which made significant progress in solving emergency problems in hydraulic engineering. Wang
et al. (
2021) integrated the TODIM method with binary semantic Pythagorean fuzzy sets to develop innovative models and concepts for the scientific and comprehensive assessment of rural scientific and technological talent. Guo
et al. (
2020) first defined a new Probabilistic linguistic Hamming distance and improved the classical TODIM method, making the improved TODIM method more accurate and effective in industrial detection of carbon dioxide storage locations. Rosli
et al. (
2023) first aggregated expert evaluation information expressed in binary semantic sets using the LAMA (Linguistic Aggregation Majority Additive Operator) operator, and then ranked six candidate partners using the TODIM method, selecting the candidate partner with the highest score. Wu
et al. (
2020) first integrated DEMATEL method with entropy weight method to determine attribute weights, and then evaluated and ranked eight candidate hilly sites by combining PDHLTS and TODIM, and selected the best hilly site selection. Furthermore, to assess the rationality of product recycling channels from a scientific perspective, Hong
et al. (
2021) first established a complete evaluation index system, then used interval type-2 fuzzy numbers to represent decision information, and finally used TODIM method for sorting. Although the classic TODIM is built on the basis of PT (the value function and probability weight function in prospect theory function effectively reflect the loss aversion psychology of DMs and reveal the irrational factors of DM’s behaviour), the core idea of PT has not been reflected in it. To this end, Tian
et al. (
2019) introduced the PT theory to improve the TODIM method and constructed an enhanced TODIM method. This study introduces behavioural theory into decision theory, achieving further improvement of decision theory. This article will improve the traditional TODIM method from a new perspective by introducing a new behavioural theory-regret theory which are proposed by Loomes and Sugden (
1982) and Bell (
1982) to enhance the TODIM method. The improved TODIM method retains both the traditional TODIM method’s ability to represent DMs’ loss aversion attitudes and their regret aversion psychology.
Regret theory (RT) (Bleichrodt
et al.,
2010) is another important behavioural theory after PT, which combines emotional and motivational factors into the expectancy structure to express DM’s regret and disgust psychology. RT believes that DMs not only focus on its own chosen options, but also on other unselected options. When the outcomes of other unchosen options surpass those of the chosen option, DMs may experience regret; conversely, they may feel happiness if the selected option performs better. Currently, robust techniques have been utilized in the decision-making domain to tackle numerous real-world decision-making challenges (Hu,
2023; Li
et al.,
2021; Liao
et al.,
2022; Mondal
et al.,
2023; Wang
et al.,
2018). For instance, Liu
et al. (
2020) developed a comprehensive model for sustainable supplier selection that combines RT and QUALIFLEX methods within a two-dimensional uncertain linguistic context, significantly enhancing the reliability of DM’s evaluations. Jia and Wang (
2020) introduced the PROMETHEE II method, grounded in RT, to address the selection of cloud services for universities in a PLTS. Hu (
2023) noted that many existing MADM methods neglect the optimal efficiency of the MADM process and the preferences of DMs. To remedy this gap, the MADM method approach based on RT was suggested. Liang and Wang (
2020) enhanced urban emergency response capabilities by developing interval hesitant fuzzy satisfaction models. Qian
et al. (
2019) incorporated RT into the MADM process and proposed a novel grey risk MADM method to tackle the challenge of selecting mall locations. Liu
et al. (
2023) introduced RT to establish an overall merit model for the urgent relief system of mines, addressing the complexity, ambiguity, and systematicity of the evaluation. Zhang
et al. (
2021) proposed a case retrieval method for handling multiple attributes and incomplete weight information based on RT and LINMAP methods. Zhao
et al. (
2023) incorporated RT into an uncertain linguistic context and introduced the interaction between doctors and patients in an online setting, along with the concept of stable matching model, conducting thorough research on the issue with incomplete information. Due to the complexity of construction projects, selecting capable managers is crucial for their success. Yan
et al. (
2023) integrated the RT with the fuzzy DEMATEL approach to create a MADM model for selecting construction project managers. Furthermore, to assess the specific combat capabilities of a particular fighter jet, Zhang
et al. (
2023a) adapted the RT and CRITIC methods for use in a Pythagorean hesitant fuzzy (PHF) context, introducing an enhanced method to address random issues within this environment. Additionally, to evaluate five renewable energy options, Ding
et al. (
2023) developed an improved hybrid MADM method that combines DEMATEL and RT. Considering the influence of fuzzy information and irrational behaviour in reality, DM often finds it difficult to make a decision. Therefore, Zhang
et al. (
2023b) introduced the VIKOR method utilizing RT to tackle the MADM issue in situations where the weight information is entirely unknown. In summary, utilizing PDHLTS to express decision information and establishing the TODIM method that considers DMs’ behavioural psychology based on RT in the PDHL environment has certain significance for the development of the decision-making field.
The organization of this article: the Section
2 offers a brief overview of essential theoretical concepts relevant to our research, including PDHLTS, RT theory, and traditional TODIM methods. In Section
3, we develop a weight calculation method utilizing the PDHLTS distance measure and PDHLWA operator for the PDHL context, referred to as the CCSD method. Additionally, we expand the perceived utility function in RT to assess the regret and joy associated with the overall advantage flow of alternatives determined by the TODIM method in the PDHL setting, leading to the creation of the MADM method that captures the regret and aversion feelings of DMs, called the RT-PDHL-TODIM method. Section
4 presents specific examples for information system investment project selection to demonstrate the effectiveness of the CCSD and RT-PDHL-TODIM methods proposed in this paper, along with a parameter analysis to further confirm their effectiveness, superiority, and innovation by comparing them to existing methods like PDHL-WASPAS and PDHL-TOPSIS. Finally, Section
5 concludes the article with a summary.
3 The PDHL CCSD and PDHL-RT-TODIM Method for MADM Problem
Next, based on the RT theory, PDHLTS theory, and classic TODIM method, we will construct the PDHL-RT-TODIM method. The mathematical symbols required are described: let $\Lambda =\{{\Lambda _{1}},{\Lambda _{2}},\dots ,{\Lambda _{s}}\}$, $\Upsilon =\{{\Upsilon _{1}},{\Upsilon _{2}},\dots ,{\Upsilon _{t}}\}$ represent sets of alternatives and evaluation attributes, and $\omega =({\omega _{1}},{\omega _{2}},\dots ,{\omega _{t}})$ represent the weight vector of the evaluation attribute, satisfying ${\omega _{j}}\geqslant 0,$
${\textstyle\sum _{j=1}^{t}}{\omega _{j}}=1$. The PDHL evaluation information of the attribute ${\Upsilon _{j}}$ for the alternative ${\Lambda _{i}}$ is represented ${\mathbb{Z}_{ij}}=\big\{{\mathbb{Z}_{ij}^{(h)}}({p_{ij}^{(h)}})\big|{\mathbb{Z}_{ij}^{(h)}}\in \Theta ,{p_{ij}^{(h)}}\gt 0,{\textstyle\sum _{h=1}^{\mathrm{\# }{\mathbb{Z}_{ij}}}}{p_{ij}^{(h)}}\leqslant 1\big\}$ and $G={\{{\mathbb{Z}_{ij}}\}_{s\times t}}$ is the decision matrix.
3.1 Calculation of the Weight of Attributes
The following will provide the detailed process of extending the classical CCSD method (Wang and Luo,
2010) to the PDHL environment and using it to determine the weights of attributes.
Step 1. By Definition
6, supplement the elements of PDHLTS, so that each supplemented PDHLTS has the same number of elements. According to Definition
6, normalize the evaluation information, and the cost details are converted into benefit details as follows:
${\mathbb{Z}_{ij}}(P)=\big\{{\mathbb{Z}_{ij}^{(h)}}({p_{ij}^{(h)}})\big|{\mathbb{Z}_{ij}^{(h)}}\in \Theta ,{p_{ij}^{(h)}}\gt 0,{\textstyle\sum _{h=1}^{\mathrm{\# }{\mathbb{Z}_{ij}}}}{p_{ij}^{(h)}}\leqslant 1\big\}$ was changed to evaluation information
${\mathbb{Z}_{ij}}h=\big\{-{\mathbb{Z}_{ij}^{(h)}}({p_{ij}^{(h)}})\big|-{\mathbb{Z}_{ij}^{(h)}}\in \Theta ,{p_{ij}^{(h)}}\gt 0,{\textstyle\sum _{h=1}^{\mathrm{\# }{\mathbb{Z}_{ij}}}}{p_{ij}^{(h)}}\leqslant 1\big\}$.
Step 2. Determine the total evaluation score for each alternative by omitting the evaluation score for the attribute
${\Upsilon _{j}}$ using the PDHLWA operator.
Among them,
${\omega _{l}}$ represents the weight of the attribute
${\Upsilon _{l}}$, which satisfies
${\omega _{l}}\in [0,1]$ and
${\textstyle\sum _{l=1}^{t}}{\omega _{l}}=1$.
Step 3. Compute the CC between the attribute
${\Upsilon _{j}}$ and the overall assessment data.
where,
Among them,
$CC({\Upsilon _{j}})$,
${\bar{\mathbb{Z}}_{j}}$ and
${\bar{\mathbb{Z}}^{\prime }_{j}}$, respectively, represents the CC between the attribute
${\Upsilon _{j}}$ and the overall assessment data, as well as the average value of the attribute
${\Upsilon _{j}}$ and the average value of the overall evaluation value excluding attribute
${\Upsilon _{j}}$.
-
i) In the above equation, $CC({\Upsilon _{j}})$ varies from −1 to 1. When $CC({\Upsilon _{j}})$ is near 1, that means the absence/presence of attribute did not contribute much to the change in evaluation value and final alternatives’ ranking. At this point, attributes ${\Upsilon _{j}}$ should have less importance, and should be weighted with a smaller value.
-
ii) As $CC({\Upsilon _{j}})$ nears −1, it suggests that the removal of attribute ${\Upsilon _{j}}$ significantly affected the score and the ranking of the options. Therefore, attribute ${\Upsilon _{j}}$ should be assigned more importance.
-
iii) Furthermore, it is important to take into account how deviations affect the overall evaluation score and the final ranking of options. If an attribute provides the same utility across all alternatives, eliminating it from the attribute set will not influence the decision. That is to say, attributes with higher SD should carry more significance, while those with lower standard deviations should be given less importance.
Step 4. Based on the above analysis, calculate the weights of the attributes.
where,
$D({\Upsilon _{j}})=\sqrt{\frac{1}{s}\big({\textstyle\sum _{i=1}^{s}}\big({\textstyle\sum _{h=1}^{\mathrm{\# }{\mathbb{Z}_{ij}}}}{\big(f({\mathbb{Z}_{ij}^{(h)}}){\tilde{p}_{ij}^{(h)}}-f({\bar{\mathbb{Z}}_{ij}^{(h)}}){\bar{\tilde{p}}_{ij}^{(h)}})\big)^{2}}\big)}$ was the standard deviation of the evaluation information under attribute.
Equation (
12) represented a nonlinear system of equations with
t equations that uniquely identify
t weight variables. To address this equation, we reformulated it into the subsequent nonlinear optimization model:
The optimal solution is ${\omega _{j}}$, which minimized the value of equation J. Among them, ${\omega _{j}}$ represents the weight of the ${\Upsilon _{j}}$ and satisfies ${\omega _{j}}\in [0,1],{\textstyle\sum _{j=1}^{t}}{\omega _{j}}=1.$
The nonlinear optimization model mentioned can be addressed by Microsoft Excel with macros, MATLAB, or LINGO software to find the best possible value of the objective function while adhering to the given constraints.
3.2 The PDHL-RT-TODIM Method for Ranking Alternatives
The RT theory is introduced into PDHLTS, and the constructed PDHL-RT-TODIM method is as follows.
Step 1. Calculate the relative weight of each attribute.
where
${\varpi _{j}}$ represents the relative weight of attribute
${\Upsilon _{j}}$, and
${\omega _{l}}=\max \{{\omega _{1}},\dots ,{\omega _{j}},\dots ,{\omega _{t}}\}$.
Step 2. Calculate the advantage of alternative
${\Lambda _{i}}$ over other alternatives under attribute
${\Upsilon _{j}}$.
where
$HD({\tilde{\mathbb{Z}}_{ij}}-{\tilde{\mathbb{Z}}_{dj}})=\frac{{\textstyle\sum _{h=1}^{\mathrm{\# }{\tilde{\mathbb{Z}}_{ij}}}}\big|f({\mathbb{Z}_{ij}^{(h)}}){\tilde{P}_{ij}^{(h)}}-f({\mathbb{Z}_{dj}^{(h)}}){\tilde{P}_{dj}^{(h)}}\big|}{\mathrm{\# }{\tilde{\mathbb{Z}}_{ij}}},$ and
$\theta (\theta \gt 0)$ represents the loss attenuation coefficient.
Step 3. Calculate the overall advantage of alternative
${A_{i}}$ relative to other alternatives.
Step 4. Calculate the comprehensive advantage of each alternative.
Step 5. Calculate the standardized comprehensive advantages of each alternative.
Step 6. Determine the utility value and the regret-joy value for each alternative.
The utility value for each option was determined in the following manner
The regret-joy value for each alternative was determined in the following manner:
where
$U{V^{+}}=\max \{UV({A_{1}}),\dots ,UV({A_{2}}),\dots ,UV({A_{s}})\},U{V^{-}}=\min \{UV({A_{1}}),\dots ,UV({A_{2}}),\dots ,UV({A_{s}})\},$ $\alpha (\alpha \in (0,1))$ represents the risk attitude coefficient, and
$\vartheta (\vartheta \gt 0)$ represents the regret aversion coefficient.
Step 7. Rank the alternatives based on their utility value and regret-joy value, and the higher the evaluation value, the better the ranking.
5 Conclusion
Since RT in behavioural psychology can accurately depict the emotions and motivations of DMs during the MADM process, it is integrated into this process. The traditional TODIM method is improved for the PDHLTSs environment, resulting in the creation of the PDHL-RT-TODIM method, which seeks to thoroughly capture the emotions and motivations of DMs throughout their decision-making journey. Furthermore, the CCSD method is refined to effectively and reasonably assess attribute weights in the PDHL environment when these weights are completely unknown. The practicality of the proposed method is demonstrated through numerical examples for information system investment project selection, and its stability, effectiveness, and benefits are further confirmed through sensitivity analysis of parameters and comparisons with existing methods. As a result, the method presented in this section not only accurately reflects the psychological and behavioural characteristics of DMs with different risk attitudes when assessing gains and losses but also accommodates their preferences by allowing for parameter adjustments.
This article integrates RT into the decision-making process, which can accurately describe the emotions and motivations of DM in the MADM process, making the decision-making results more accurate and effective. In future research, the method established in this article has certain guiding significance for other practical MADM problems (He and Jiang,
2025; Liao
et al.,
2023; Zhang
et al.,
2025). However, the discussion in this article about the psychological factors of decision-makers in the decision-making process is incomplete. If the impact of decision-makers’ preference attitudes towards profit loss on decision-making results is not discussed, we will focus on exploring this aspect in the future.
Compliance with ethical standards
Ethical approval
This article does not contain any studies with human participants or animals performed by any of the authors.
Conflict of interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Data availability statement
The data used to support the findings of this study are included within the article.