Relative Importance Of Different Attributes Research Articles

Life after "no": barriers to behavior change for persons declined hernia repair due to high-risk features.

Delaying an elective operation to mitigate risk factors improves patient outcomes. Elective ventral hernia repair is one such example. To address this issue, we developed a pre-operative optimization clinic to support high-risk patients seeking elective ventral hernia repair. Unfortunately, few patients progressed to surgery. Within this context, we sought to understand the barriers to behavior change among these patients with the goal of improving care for patients undergoing elective surgery. We performed semi-structured, qualitative interviews with 20 patients who were declined ventral hernia repair due to either active tobacco use or obesity. Patients were recruited from a pre-operative optimization clinic at an academic hospital. Interviews sought to characterize patients' perceived barriers to behavior change. Interviews were concluded once thematic saturation was reached. We used an inductive thematic analysis to analyze the data. All data analysis was performed using MAXQDA software. Among 20 patients (mean age 50, 65% female, 65% White), none had yet undergone ventral hernia repair. While most patients had a positive experience in the clinic, among those who did not, we found three dominant themes around behavior change: (1) Patient's role in behavior change: how the patient perceived their role in making behavior changes optimize their health for surgery; (2) Obtainability of offered resources: the need for more support for patients to access the recommended healthcare; and (3) Patient-provider concordance: the extent to which patients and providers agree on the relative importance of different attributes of their care. Behavior change prior to elective surgery is complex and multifaceted. While improving access to tobacco cessation resources and obesity management may improve outcomes for some, patients may benefit from increased on-site facilitation to promote access to resources as well as the use of patient-facing decision support tools to promote patient-provider concordance.

Public Preferences for Determining Eligibility for Screening in Risk-Stratified Cancer Screening Programs: A Discrete Choice Experiment.

Risk stratification has been proposed to improve the efficiency of population-level cancer screening. We aimed to describe and quantify the relative importance of different attributes of potential screening programs among the public, focusing on stratifying eligibility. We conducted a discrete choice experiment in which respondents selected between 2 hypothetical screening programs in a series of 9 questions. We presented the risk factors used to determine eligibility (age, sex, or lifestyle or genetic risk scores) and anticipated outcomes based on eligibility criteria with different sensitivity and specificity levels. We performed conditional logit regression models and used the results to estimate preferences for different approaches. We also analyzed free-text comments on respondents' views on the programs. A total of 1,172 respondents completed the survey. Sensitivity was the most important attribute (7 and 11 times more important than specificity and risk factors, respectively). Eligibility criteria based on age and sex or genetics were preferred over age alone and lifestyle risk scores. Phenotypic and polygenic risk prediction models would be more acceptable than screening everyone aged 55 to 70 y if they had high discrimination (area under the receiver-operating characteristic curve ≥0.75 and 0.80, respectively). Although our sample was representative with respect to age, sex, and ethnicity, it may not be representative of the UK population regarding other important characteristics. Also, some respondents may have not understood all the information provided to inform decision making. The public prioritized lives saved from cancer over reductions in numbers screened or experiencing unnecessary follow-up. Incorporating personal-level risk factors into screening eligibility criteria is acceptable to the public if it increases sensitivity; therefore, maximizing sensitivity in model development and communication could increase uptake. The public prioritized lives saved when considering changing from age-based eligibility criteria to risk-stratified cancer screening over reductions in numbers of people being screened or experiencing unnecessary follow-up.The risk stratification strategy used to do this was the least important component, although age plus sex or genetics were relatively preferable to using age alone and lifestyle risk scores.Communication strategies that emphasize improvements in the numbers of cancers detected or not missed across the population are more likely to be salient than reductions in unnecessary investigations or follow-up among some groups.Future research should focus on developing implementation strategies that maximize gains in sensitivity within the context of resource constraints and how to present attributes relating to specificity to facilitate understanding and informed decision making.

P539 Patient Preferences for Inflammatory Bowel Disease Treatments: Development of a European Preference Survey using a Discrete Choice Experiment

Abstract Background There is a growing consensus across stakeholders on the value of patient preference (PP) studies, as recognized by the European Medicines Agency and the European Network for Health Technology Assessment. This study aimed to develop a PP survey to quantitatively evaluate which characteristics are most important to inflammatory bowel disease (IBD) patients, so that the results can inform the medicinal product life cycle (MPLC). Methods Following the PREFER recommendations, a four-step approach was followed to develop the PP survey: 1) stated preference method selection, 2) attribute and level development, 3) survey implementation, and 4) survey piloting. Throughout the different steps of the survey development, an advisory board (AB) consisting out of patients, patient organizations, gastroenterologists, IBD nurses, and statisticians were consulted. Results First, a discrete choice experiment (DCE) was chosen as the preferred elicitation method because it allows to reach the objectives of the survey, namely to: 1) quantify the relative importance of different attributes, 2) elicit the trade-offs patients make, and 3) measure preference heterogeneity. Second, a scoping literature review of IBD clinical trials, available IBD treatments, and previously published preference studies was performed. Discussions on these characteristics with patients (n=11) during focus group discussions (FGDs) using the nominal group technique revealed the following patient prioritized characteristics: prevent surgery, long-term clinical remission, improved quality of life, occurrence of urgency, and improved labor rate. Based upon the results of the FGDs, a preliminary list of possible attributes for inclusion in the DCE was refined during AB meetings. This list was iteratively adapted until consensus was found on 14 attributes, their levels, and corresponding explanations (Figure 1). Third, the DCE survey was designed to include these 14 attributes using partial profiles next to measures about sociodemographic variables, health literacy, and treatment experience. Fourth, piloting the study with IBD patients (n=4) revealed that the survey was comprehensible, had a good flow, and contained graphics that supported the content. Only minor text edits were needed. Conclusion It is key to develop a PP survey in partnership with patients and other members of the AB. This survey will be rolled out across Europe in 11 different languages and will increase understanding of which treatment aspects are most important to IBD patients. These aspects should be included in drug development and evaluation so that the MPLC can be more patient-centered and future treatments will target aspects that are most important to IBD patients themselves.

Designing job ads to stimulate the decision to apply: a discrete choice experiment with business students

This study advances a differentiated understanding of job ad pre-hire effectiveness. It analyzes the utility values for varying levels of job ad attributes through a hierarchical Bayesian approach to conjoint analysis. This method allows not only to measure the relative importance of different attributes on the individual level but also to explore heterogeneity in evaluations influenced by educational level, international career orientation and time to graduation. The main results from the experiment show that for both undergraduate and graduate business students, salary and opportunity for advancement by far outweigh employer familiarity and the description of job-related tasks. The study contributes to the recruitment literature by assessing to what extent these four core attributes of a job ad drive job pursuit intentions. It also discusses the implications of attribute trade-offs for employer branding activities.

Tüketicilerin Balık Satın Alma Tercihlerinin Konjoint Analizi Kullanılarak Belirlenmesi: Türkiye Üzerine Bir Pilot Çalışma

The emphasis of this study is to investigate, the relative importance of different attributes (fish type, production method, place of purchase and price) on consumer perception for the fish purchase decision-making process. The data employed in this paper were taken from a face to face cross-sectional survey conducted with 526 individuals in the biggest cities (Istanbul, Ankara, Izmir, Trabzon, Adana, Van, and Gaziantep) of the seven regions of Turkey during the period July-September 2018. The questionnaire was consisting of two parts; questions on socio-demographic characteristics of the sample and the choice card. The data were analyzed using descriptive statistics, and conjoint analysis by SPSS© 21. Results show that with regard to consumer perception, place of purchase is the most important product attribute for choosing fish. The importance is line-up as price, production method and fish type. Within the place of purchase options most preferred one is the fish markets. They also prefer wild fish, sea bass and logically minimum price level compared with the designated alternatives.

Development and usability testing of a multi-criteria value clarification methods for patients with localized prostate cancer.

Current guidelines for the development of decision aids recommend that they have to include a process for helping patients clarify their personal values, for example, by using values clarification methods. In this article, we extensively described the development process of the web-based values clarification method for patients with localized low- to intermediate-risk prostate cancer based on the analytic hierarchy process. With analytic hierarchy process, the relative importance of different attributes of available treatments can be determined through series of pairwise comparisons of potential outcomes. Furthermore, analytic hierarchy process is able to use this information to present respondents with a quantitative overall treatment score and can therefore give actual treatment advice upon patients' request. The addition of this values clarification method to an existing web-based treatment decision aid for patients with localized prostate cancer is thought to improve the support offered to patients in their decision-making process and their decision quality.

Assessment of surface water quality using Fuzzy Analytic Hierarchy Process (FAHP): A case study of Piyain River's sand and gravel quarry mining area in Jaflong, Sylhet

The aim of this study is to assess the quality of surface water of Piyain River adopting two different approaches. The first approach, determines the classification of water samples by the traditional water quality index, and the second one is focused on water classification analysis with the aid of the Mamdani Fuzzy Logic (MFL). For this case, the relative weight of water quality parameter is computed based on the Analytic Hierarchy Process (AHP). The AHP is a multiple criteria decision making procedure which provides a methodology to calibrate the numeric scale for the measurement of quantitative as well as qualitative performances. The relative importance of different attributes is given on a scale from 1 to 9. In fuzzy water quality assessment procedure, the trapezoidal membership functions are used because of its highest classification accuracy. Also, it can characterize the dynamic behavior of the water quality parameters. Twenty-one parameters are tested for the assessment of water quality. However, arsenic is not found in the water samples, so the rest twenty parameters is divided into three groups for utilizing the hierarchy by grouping some criteria. Total sixty-nine rules are used, three for each indicator and three for each partial group. In hydro-chemical analysis it is found that typical value of Sulfate (0.12–2.8 mg/L), Sodium (2–5.7 mg/L), Chloride (1.05–4.11 mg/L), Potassium (0.4–2.6 mg/L) is extremely lower thanstandard value where the standard for Bangladesh is 400 mg/L, 200 mg/L, 150–600 mg/L, 12 mg/L respectively. Specific Conductivity (45.7–135 μS/cm), Calcium (5.5–28 mg/L), Magnesium (1–24.5 mg/L) are below standard where the standard values are 500 μS/cm, 75 mg/L, 30–35 mg/L correspondingly. The measured value of pH (6.31–6.96) is between WHO and Bangladesh standard (6.5–8.5). Turbidity (3.5–99 NTU) is higher with respect to WHO guideline (5 NTU) &Bangladesh standard (10 NTU). The computed WQI value ranges from 19.84 to 154.21 whereas, FWQI1 and FWQI2 value ranges from 47.6 to 78.4 and from 51.8 to 80.7, respectively. It suggests that the surface water of the river exhibits good water condition. Besides, the quality of water sample from quarry area is found average to good. In a nutshell, FWQI2is more reliable than FWQI and WQI. Hence, it can be applied for monitoring water quality problem locally or regionally.

A novel design process for selection of attributes for inclusion in discrete choice experiments: case study exploring variation in clinical decision-making about thrombolysis in the treatment of acute ischaemic stroke

BackgroundA discrete choice experiment (DCE) is a method used to elicit participants’ preferences and the relative importance of different attributes and levels within a decision-making process. DCEs have become popular in healthcare; however, approaches to identify the attributes/levels influencing a decision of interest and to selection methods for their inclusion in a DCE are under-reported. Our objectives were: to explore the development process used to select/present attributes/levels from the identified range that may be influential; to describe a systematic and rigorous development process for design of a DCE in the context of thrombolytic therapy for acute stroke; and, to discuss the advantages of our five-stage approach to enhance current guidance for developing DCEs.MethodsA five-stage DCE development process was undertaken. Methods employed included literature review, qualitative analysis of interview and ethnographic data, expert panel discussions, a quantitative structured prioritisation (ranking) exercise and pilot testing of the DCE using a ‘think aloud’ approach.ResultsThe five-stage process reported helped to reduce the list of 22 initial patient-related factors to a final set of nine variable factors and six fixed factors for inclusion in a testable DCE using a vignette model of presentation.ConclusionsIn order for the data and conclusions generated by DCEs to be deemed valid, it is crucial that the methods of design and development are documented and reported. This paper has detailed a rigorous and systematic approach to DCE development which may be useful to researchers seeking to establish methods for reducing and prioritising attributes for inclusion in future DCEs.

Patient preferences for personalized (N-of-1) trials: a conjoint analysis

ObjectiveDespite their promise for increasing treatment precision, Personalized Trials (i.e., N-of-1 trials) have not been widely adopted. We aimed to ascertain patient preferences for Personalized Trials. Study Design and SettingWe recruited 501 adults with ≥2 common chronic conditions from Harris Poll Online. We used Sawtooth Software to generate 45 plausible Personalized Trial designs comprising combinations of eight key attributes (treatment selection, treatment type, clinician involvement, blinding, time commitment, self-monitoring frequency, duration, and cost) at different levels. Conditional logistic regression was used to assess relative importance of different attributes using a random utility maximization model. ResultsOverall, participants preferred Personalized Trials with no costs vs. $100 cost (utility difference 1.52 [standard error 0.07], P < 0.001) and with less vs. more time commitment/day (0.16 [0.07], P < 0.015) but did not hold preferences for the other six attributes. In subgroup analyses, participants ≥65 years, white, and with income ≤$50,000 were more averse to costs than their counterparts (P all <0.05). ConclusionTo optimize dissemination, Personalized Trial designers should seek to minimize out-of-pocket costs and time burden of self-monitoring. They should also consider adaptive designs that can accommodate subgroup differences in design preferences.

A hedonic price model for ski lift tickets in the Dolomites

PurposeDifferent, alternative or complementary strategies have been advanced for the rejuvenation of the ski tourism product, thus favoring its economic and environmental sustainability. This paper aims to provide new suggestions by looking at the determinants of ski lift ticket prices in the Dolomites.Design/methodology/approachThe paper uses a hedonic price model approach, which allows the identification of the relative importance of different attributes on the determination of a product price.FindingsThe model shows that a higher level of investment in modern lifts and snowmaking equipment undertaken by the resort pays off in terms of customers’ perceived value-for-money relationship. The same is not true for investments in the enlargement of the skiable surface or the introduction of night skiing options and illuminated slopes. The authors found evidence that non-participatory activities, such as different winter sports and on-slope entertainment, can improve the customer’s perception of resorts’ quality. Finally, reputation plays an important role in determining the customers’ perception of good value-for-money destinations and deals.Originality/valueWith respect to previous works, the research expands the range of attributes possibly impacting ski lift ticket prices. Identifying crucial elements consumers would be willing to pay for allows managers to re-think and adjust their products and prices accordingly, improving the economic sustainability of the ski tourism product.

Estimating welfare impacts where property rights are contested: methodological and policy implications

Where rights over natural resources are contested, the effectiveness of conservation may be undermined and it can be difficult to estimate the welfare impacts of conservation restrictions on local people. In particular, researchers face the dilemma of estimating respondents’ Willingness To Pay (WTP) for rights to resources, or their Willingness To Accept (WTA) compensation for foregoing these rights. We conducted a discrete choice experiment with respondents living next to a new protected area in Madagascar, using a split-sample design to administer both WTP and WTA formats, followed by debriefing interviews. We first examined the differences in response patterns to the formats and their performance in our study context. We also used the two formats to elicit respondents’ attitudes to conservation restrictions and property rights over forestlands. We found that the format affected the relative importance of different attributes: WTA respondents strongly favoured livelihood projects and secure tenure whereas neither attributes were significant for WTP respondents. The WTA format outperformed WTP format on three validity criteria: it was perceived to be more plausible and consequential; led to fewer protest responses; and was more appropriate given very low incomes. Seventy-three percent of respondents did not accept the legitimacy of state protection and strongly aspired to secure forest tenure. The use of a WTP format may thus be inappropriate even if respondents do not hold formal rights over resources. We conclude that estimating the opportunity costs of stopping de jure illegal activities is difficult and coercive conservation lacks procedural legitimacy and may not achieve full compensations. Our findings question the viability of the current conservation model and highlight the importance to conservation policy of locally legitimate property rights over forestlands.

Probing the relative importance of different attributes in L2 reading and listening comprehension items: An application of cognitive diagnostic models

The present study examines the relative importance of attributes within and across items by applying four cognitive diagnostic assessment models. The current study utilizes the function of the models that can indicate inter-attribute relationships that reflect the response behaviors of examinees to analyze scored test-taker responses to four forms of TOEFL reading and listening comprehension sections. The results are interpreted to determine whether the subskills defined in each subtest contribute equally within an item and across items. The study also discusses whether the empirical results support the claims for compensatory processing of L2 comprehension skills and presents practical implications of the findings. The article concludes with the limitations of the study and suggestions for future research.

Isolated trees as nuclei of regeneration in tropical pastures: testing the importance of niche‐based and landscape factors

AbstractQuestionsOur study tests the relative importance of different attributes of isolated trees in explaining the properties of the regeneration assemblage beneath their crowns to evaluate their effect on the composition of early successional stages and understand the processes underlying this effect. We asked: (1) does the regeneration assemblage contain a high proportion of individuals conspecific with the isolated tree; (2) how does the landscape surrounding an isolated tree influence the properties of the regeneration assemblage; and (3) what is the respective importance of structural variables and functional traits of isolated trees for their influence on the properties of the regeneration assemblage?LocationThree pasture sites in Guanacaste Province, a tropical seasonally dry area, Costa Rica.MethodsNinety isolated trees were characterized by their position in the landscape relative to patches of trees, individual structural variables related to tree and crown size, and species functional traits. The assemblage of woody plants regenerating under their crowns was characterized by number of individuals and species, and taxonomic and functional composition. To understand the mechanisms underlying the facilitative effect of isolated trees on regeneration, correlations between their attributes and properties of the regeneration assemblage were assessed.ResultsWe found that a low proportion of regenerating individuals were conspecific with the isolated trees beneath which they have established. Landscape factors influenced the regeneration but their effects were site‐dependent. The attributes of isolated trees correlated well with the functional composition of the regeneration assemblage: their structure and phenological habits with traits associated with drought tolerance, and their dispersal syndrome with the dispersal syndrome of the regeneration assemblage. However, isolated tree attributes correlated poorly with the regeneration assemblage's taxonomic composition.ConclusionsOur study shows that an approach based on functional composition can provide a better understanding of community assembly mechanisms than does a taxonomic approach. Two main mechanisms are suggested to explain the influence of isolated trees on the regeneration assemblage: modification of micro‐scale environmental conditions (shade and moisture) and influence on dispersal agents. The effect of attributes of isolated trees on the properties of the regeneration assemblage predicts a long‐term legacy of the early stages of succession.

Relative Importance of Different Attributes of Graphic Health Warnings on Tobacco Packages in Viet Nam.

Graphic health warnings (GHW) on tobacco packages have proven to be effective in increasing quit attempts among smokers and reducing initial smoking among adolescents. This research aimed to examine the relative importance of different attributes of graphic health warnings on tobacco packages in Viet Nam. A discrete choice experimental (DCE) design was applied with a conditional logit model. In addition, a ranking method was used to list from the least to the most dreadful GHW labels. With the results from DCE model, graphic type was shown to be the most important attribute, followed by cost and coverage area of GHW. The least important attribute was position of the GHW. Among 5 graphic types (internal lung cancer image, external damaged teeth, abstract image, human suffering image and text), the image of lung cancer was found to have the strongest influence on both smokers and non-smokers. With ranking method, the image of throat cancer and heart diseases were considered the most dreadful images. GHWs should be designed with these attributes in mind, to maximise influence on purchase among both smokers and non-smokers.

Using Best-Worst Scaling to Measure Caregiver Preferences for Managing their Child's ADHD: A Pilot Study.

Management of attention-deficit/hyperactivity disorder (ADHD) is a trade-off between caregivers' concerns about the benefits versus the risks of evidence-based treatment. Few studies have used choice-based methods to assess what treatment attributes matter most to caregivers. The aim was to develop and to pilot an instrument to elicit caregivers' preferences for evidence-based management of their child's ADHD. Mixed methods were used to develop a Best-Worst Scaling (BWS) instrument, and quantitative methods were used to pilot the instrument. Primary caregivers of children with ADHD from two community organizations were recruited for the development (n = 21) and pilot (n = 37) phase. The instrument was a BWS case 2, where 18 management profiles are presented one at a time, with respondents indicating the one best and one worst feature of each profile. Profiles were developed using a main effects orthogonal array. The mean of best-minus-worse scores was estimated, and attribute importance was based on the sum of maximum minus minimum scores for each attribute. Feasibility of eliciting stated preferences was evaluated with t tests and 95 % confidence intervals. Seven attributes (medication, therapy, school, caregiver training, provider specialty, provider communication, and out-of-pocket costs) with three levels each were identified. All mean scores were significant except for pediatrician management of the child's ADHD (p = 0.089). Caregiver training had the highest relative importance, followed by medication and provider communication. The BWS instrument was a relatively simple measure, caregivers completed it independently, and it distinguished the relative importance of different attributes in managing a child's ADHD.

Unconscious thought and deliberation without attention: A miracle or a mirage?

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Applying discrete choice modelling in a priority setting: an investigation of public preferences for primary care models

ObjectivesThe shift toward more innovative and sustainable primary care models in Italy leads policy makers and clinicians to face difficult decisions between options that are all regarded as potentially beneficial. In this study, patient preferences for different primary care models in the Tuscany region of Italy were elicited. The relative importance of different attributes to the surveyed respondents was then examined, as well as the rate at which individuals trade between attributes and the relative value of different service configurations.MethodsA discrete choice experiment survey explored the following attributes in a stratified random sample of 6,970 adults: primary care provider, diagnostic facilities and waiting time for the visit.ResultsRespondents (3,263) were likely to prefer a consultation by their own general practitioner (GP) and a practice with many diagnostic facilities. The predicted utilities of different service configurations have shown that a “primary care centre” with many diagnostic facilities was preferable to a “solo GP” model or a “group general practice”.ConclusionsThe study demonstrated how a patient choice model could be used by decision makers for developing successful policies that takes into account different healthcare needs, balancing responsiveness with care continuity, equity and appropriateness. Considering that a primary care centre would perform better than a “solo GP”, especially for younger respondents and for those with minor healthcare needs, for a more rapid diffusion of this model policymakers and managers could direct the care of primary care centres towards these targeted subgroups, at least in the first phase.

What comes first, origin or production method? An investigation into the relative importance of different attributes in the demand for eggs

This paper analyses consumer preferences for different eggs attributes to assess the importance placed by consumers on the origin and method of production when shopping. The data comes from an experiment conducted in Spain during 2009. An Error Component Random Parameter Logit model is used to estimate the effect of different eggs characteristics on consumers’ utility and derive their willingness to pay. Results suggest that consumers positively value the free-range and organic method of production and the local and regional origin and that they are willing to pay an additional € 0.85 for each package of six free-range or organic eggs, € 0.77 for locally produced and € 0.27 for regional produced eggs. Hence, the least valued eggs for consumers are those produced in cages and outside the region. Relative to this product, the highest willingness to pay corresponds to free-range or organic eggs followed by locally produced eggs and finally, by the regional eggs. Thus, we can conclude that Spanish consumers give more importance when shopping for eggs to the method of production than to the origin of production.

Consumer preferences for sea fish using conjoint analysis: Exploratory study of the importance of country of origin, obtaining method, storage conditions and purchasing price

The fishing industry plays an important role in the EU economy. Within the EU member states, Spain is the largest fish producer (catches and aquaculture) in terms of volume and also one of the major fish and fishing products consuming countries. However, despite the role of this food category in the Mediterranean diet, fish consumption might experience an important decrease in the future as a result of the changes in food habits observed over the last years. The main objective of the present paper was to investigate, by means of an exploratory study, the relative importance of different attributes on consumer perception of different factors (country of origin, obtaining method, storage conditions and purchasing price) in the decision making process when choosing sea fish in general. To achieve this goal the study was organized in two complementary steps: a qualitative approach (focus group discussions) aimed to identify which attributes and levels were considered the most relevant in the decision-making process when choosing sea fish; and a quantitative approach where conjoint analysis (CA) was applied to determine the utility values for the different levels of the selected attributes and the relative importance that these attributes have for sea fish purchasers. Among others, the most important factors for consumers when choosing sea fish were the country of origin (Spain–Morocco–Norway), the obtaining method (wild-farmed sea fish), the storage conditions (chilled-frozen) and the purchasing price (6–12–18€/kg). In general, quantitative results showed that country of origin was the most important factor when choosing sea fish, although other related factors such as perceived fish freshness might be included. The three remaining attributes had a similar moderate importance, the autochthonous fresh wild sea fish sold at 6–12€/kg being the preferred option. Only one segment of consumers (19.6%) preferred farmed sea fish instead of wild sea fish. However the relative importance of the obtaining method attribute compared to the country of origin or the storage condition was very low. Based on these results, effective information strategies seem to be needed in order to support and increase farmed sea fish consumption, thus reducing the impact of unsustainable fishing practices and facing up to the overexploitation of the natural fish resources.

The local geometry of multiattribute tradeoff preferences

Existing representations for multiattribute ceteris paribus preference statements have provided useful treatments and clear semantics for qualitative comparisons, but have not provided similarly clear representations or semantics for comparisons involving quantitative tradeoffs. We use directional derivatives and other concepts from elementary differential geometry to interpret conditional multiattribute ceteris paribus preference comparisons that state bounds on quantitative tradeoff ratios. This semantics extends the familiar economic notion of marginal rate of substitution to multiple continuous or discrete attributes. The same geometric concepts also provide means for interpreting statements about the relative importance of different attributes.