Model Misspecification in Multiattribute Parameter Estimation

1981 ◽  
Vol 18 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Frank J. Carmone ◽  
Paul E. Green
Keyword(s):  
Parameter Estimation ◽  
Experimental Design ◽  
Conjoint Analysis ◽  
Model Misspecification ◽  
Utility Functions ◽  
Individual Level ◽  
Data Points ◽  
The Individual ◽  
Main Effects

Most applications of conjoint analysis have emphasized main-effects models, largely because fewer data points are needed to fit that type of model at the individual level. The authors suggest that such simplifications can lead to poor predictions when the underlying utility functions depart from the simplicity of a main-effects model. They also show how compromise designs, which allow orthogonal estimation of selected two-way interactions (as well as main effects), can provide a more general experimental design in cases where a specified set of two-way interactions is suspected.

scholarly journals The Online Elicitation of Personal Utility Functions (OPUF) tool: a new method for valuing health states

2022 ◽  
Vol 7 ◽  
pp. 14
Author(s):  
Paul Schneider ◽  
Ben van Hout ◽  
Marike Heisen ◽  
John Brazier ◽  
Nancy Devlin
Keyword(s):  
Utility Functions ◽  
Health State ◽  
Group Level ◽  
Health States ◽  
Online Tool ◽  
Value Set ◽  
Individual Level ◽  
Personal Utility ◽  
Value Sets ◽  
The Individual

Introduction Standard valuation methods, such as TTO and DCE are inefficient. They require data from hundreds if not thousands of participants to generate value sets. Here, we present the Online elicitation of Personal Utility Functions (OPUF) tool; a new type of online survey for valuing EQ-5D-5L health states using more efficient, compositional elicitation methods, which even allow estimating value sets on the individual level. The aims of this study are to report on the development of the tool, and to test the feasibility of using it to obtain individual-level value sets for the EQ-5D-5L. Methods We applied an iterative design approach to adapt the PUF method, previously developed by Devlin et al., for use as a standalone online tool. Five rounds of qualitative interviews, and one quantitative pre-pilot were conducted to get feedback on the different tasks. After each round, the tool was refined and re-evaluated. The final version was piloted in a sample of 50 participants from the UK. A demo of the EQ-5D-5L OPUF survey is available at: https://eq5d5l.me Results On average, it took participants about seven minutes to complete the OPUF Tool. Based on the responses, we were able to construct a personal EQ-5D-5L value set for each of the 50 participants. These value sets predicted a participants' choices in a discrete choice experiment with an accuracy of 80%. Overall, the results revealed that health state preferences vary considerably on the individual-level. Nevertheless, we were able to estimate a group-level value set for all 50 participants with reasonable precision. Discussion We successfully piloted the OPUF Tool and showed that it can be used to derive a group-level as well as personal value sets for the EQ-5D-5L. Although the development of the online tool is still in an early stage, there are multiple potential avenues for further research.

Levels of Aggregation in Conjoint Analysis: An Empirical Comparison

1980 ◽  
Vol 17 (4) ◽  
pp. 516-523 ◽  
Author(s):  
William L. Moore
Keyword(s):  
Conjoint Analysis ◽  
Predictive Power ◽  
Aggregate Level ◽  
Segmentation Method ◽  
Empirical Comparison ◽  
Individual Level ◽  
Aggregate Analysis ◽  
The Individual ◽  
Level Analysis

Two segmented methods of performing conjoint anal/sis, clustered and componential segmentation, are compared with each other as well as with individual level and totally aggregate level analyses. The two segmented methods provide insights to the data that (1) are not obtainable at the aggregate level and (2) are in a form that is more easily communicated than the information from the individual level analysis. The predictive power of the clustered segmentation method is higher than that of componential segmentation, and both are superior to the aggregate analysis but inferior to individual level analysis.

Patient and Physician Factors Associated With Adherence to Diabetes Medications

2012 ◽  
Vol 38 (3) ◽  
pp. 397-408 ◽  
Author(s):  
Antoinette M. Schoenthaler ◽  
Brian S. Schwartz ◽  
Craig Wood ◽  
Walter F. Stewart
Keyword(s):  
Medication Adherence ◽  
Primary Care Physicians ◽  
Medication Possession Ratio ◽  
Related Factors ◽  
Patient Beliefs ◽  
Individual Level ◽  
Physician Relationship ◽  
Oral Hypoglycemic Medications ◽  
The Individual ◽  
Main Effects

Purpose The purpose of this study was to examine the influence of patient and physician psychosocial, sociodemographic, and disease-related factors on diabetes medication adherence. These factors were also examined as effect modifiers of the association between quality of the patient-physician relationship and medication adherence. Methods Data were collected from 41 Geisinger Clinic primary care physicians and 608 of their patients with type 2 diabetes. Adherence to oral hypoglycemic medications was calculated using a medication possession ratio based on physician orders in electronic health records (MPREHR). MPREHR was defined as the proportion of total time in the 2 years prior to study enrollment that the patient was in possession of oral hypoglycemic medications. Linear regression was used to examine the influence of patient- and physician-level factors on adherence. Effect modification of the patient-physician relationship-adherence association was evaluated by adding the main effects of the individual-level factors and their cross-products to the models. Results In adjusted analyses, satisfaction with the physician’s patient education skills, patient beliefs about the need for their medications, and lower diabetes-related knowledge were associated with better adherence to oral hypoglycemic medications. Shorter duration of time with diabetes and taking only oral hypoglycemic medications were also associated with better adherence. Finally, the association between shared decision making and medication adherence was significantly modified by patients’ level of social support. Conclusions This study identified several patient-, physician-, and disease-related factors that should be targeted to maximize the potential for developing tailored adherence-enhancing interventions within the context of a collaborative patient-physician relationship.

Structural Reliability and Stability of Nonmetric Conjoint Analysis

1982 ◽  
Vol 19 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Naresh K. Malhotra
Keyword(s):  
Conjoint Analysis ◽  
Structural Reliability ◽  
Standard Errors ◽  
Relative Importance ◽  
Substantial Variation ◽  
Individual Level ◽  
Structural Perturbation ◽  
Estimated Parameters ◽  
Treatment Conditions ◽  
The Individual

Structural reliability and stability of nonmetric conjoint analysis are examined under conditions of severe structural perturbation and substantial variation in the number of stimulus profiles. The individual-level part worth functions are jackknifed. The jackknifed parameters, derived relative importance weights, and standard errors of estimated parameters are examined across the different treatment conditions. The results indicate that conjoint analysis is a fairly robust procedure for assessing an individual's preferences.

A Multi-Level Analysis of Organizational Justice Climate, Structure, and Employee Mental Health†

2007 ◽  
Vol 33 (5) ◽  
pp. 724-751 ◽  
Author(s):  
Chester S. Spell ◽  
Todd J. Arnold
Keyword(s):  
Mental Health ◽  
Organizational Justice ◽  
Interactive Effects ◽  
Anxiety And Depression ◽  
Individual Level ◽  
Multi Level ◽  
The Individual ◽  
Employee Mental Health ◽  
Main Effects ◽  
Level Analysis

This study uses a sample of 483 employees to investigate how fairness assessments and organizational structure relate to employee mental health. The authors explain these effects using a social contagion framework, which describes the creation of group effects that would occur in addition to individual-level influences. They found that the interactive effects of distributive and procedural justice climates significantly influence individual feelings of both anxiety and depression. This effect goes beyond the main effects of justice at the individual level.

scholarly journals Imputation Estimators Partially Correct for Model Misspecification

2011 ◽  
Vol 10 (1) ◽  
Author(s):  
Vladimir N. Minin ◽  
John D. O'Brien ◽  
Arseni Seregin
Keyword(s):  
Model Misspecification ◽  
Model Specification ◽  
Model Based Clustering ◽  
Individual Level ◽  
Inference Problems ◽  
Incomplete Observations ◽  
Genotype Frequencies ◽  
Simple Imputation ◽  
Representative Model ◽  
The Individual

Inference problems with incomplete observations often aim at estimating population properties of unobserved quantities. One simple way to accomplish this estimation is to impute the unobserved quantities of interest at the individual level and then take an empirical average of the imputed values. We show that this simple imputation estimator can provide partial protection against model misspecification. We illustrate imputation estimators’ robustness to model specification on three examples: mixture model-based clustering, estimation of genotype frequencies in population genetics, and estimation of Markovian evolutionary distances. In the final example, using a representative model misspecification, we demonstrate that in non-degenerate cases, the imputation estimator dominates the plug-in estimate asymptotically. We conclude by outlining a Bayesian implementation of the imputation-based estimation.

scholarly journals Estimating and Using Individual Marginal Component Effects from Conjoint Experiments

2021 ◽  
pp. 1-14
Author(s):  
Kirill Zhirkov
Keyword(s):  
Conjoint Analysis ◽  
Task Design ◽  
Individual Level ◽  
Individual Preferences ◽  
Political Preferences ◽  
Conjoint Experiment ◽  
The Individual ◽  
Heterogeneity Of Preferences ◽  
Additional Assumptions

Abstract Conjoint experiments are quickly gaining popularity as a vehicle for studying multidimensional political preferences. A common way to explore heterogeneity of preferences estimated with conjoint experiments is by estimating average marginal component effects across subgroups. However, this method does not give the researcher the full access to the variation of preferences in the studied populations, as that would require estimating effects on the individual level. Currently, there is no accepted technique to obtain estimates of individual-level preferences from conjoint experiments. The present paper addresses this gap by proposing a procedure to estimate individual preferences as respondent-specific marginal component effects. The proposed strategy does not require any additional assumptions compared to the standard conjoint analysis, although some changes to the task design are recommended. Methods to account for uncertainty in resulting estimates are also discussed. Using the proposed procedure, I partially replicate a conjoint experiment on immigrant admission with recommended design adjustments. Then, I demonstrate how individual marginal component effects can be used to explore distributions of preferences, intercorrelations between different preference dimensions, and relationships of preferences to other variables of interest.

scholarly journals Preseason Body Composition Adaptations in Elite White and Polynesian Rugby Union Athletes

2019 ◽  
Vol 29 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Adam J. Zemski ◽  
Shelley E. Keating ◽  
Elizabeth M. Broad ◽  
Damian J. Marsh ◽  
Karen Hind ◽  
...  
Keyword(s):  
Body Composition ◽  
Fat Mass ◽  
Lean Mass ◽  
Rugby Union ◽  
Whole Body ◽  
Body Composition Assessment ◽  
Individual Level ◽  
Individualized Approach ◽  
The Individual ◽  
Main Effects

During preseason training, rugby union (RU) athletes endeavor to enhance physical performance characteristics that are aligned with on-field success. Specific physique traits are associated with performance; therefore body composition assessment is routinely undertaken in elite environments. This study aimed to quantify preseason physique changes in elite RU athletes with unique morphology and divergent ethnicity. Twenty-two White and Polynesian professional RU athletes received dual-energy X-ray absorptiometry assessments at the beginning and conclusion of an 11-week preseason. Interactions between on-field playing position and ethnicity in body composition adaptations were explored, and the least significant change model was used to evaluate variations at the individual level. There were no combined interaction effects with the variables position and ethnicity and any body composition measure. After accounting for baseline body composition, Whites gained more lean mass during the preseason than Polynesians (2,425 ± 1,303 g vs. 1,115 ± 1,169 g; F = 5.4, p = .03). Significant main effects of time were found for whole body and all regional measures with fat mass decreasing (F = 31.1–52.0, p < .01), and lean mass increasing (F = 12.0–40.4, p < .01). Seventeen athletes (nine White and eight Polynesian) had a reduction in fat mass, and eight athletes (six White and two Polynesian) increased lean mass. This study describes significant and meaningful physique changes in elite RU athletes during a preseason period. Given the individualized approach applied to athletes in regard to nutrition and conditioning interventions, a similar approach to that used in this study is recommended to assess physique changes in this population.

scholarly journals Addressing the reliability fallacy: Similar group effects may arise from unreliable individual effects

2017 ◽  
Author(s):  
Juliane H. Fröhner ◽  
Vanessa Teckentrup ◽  
Michael N. Smolka ◽  
Nils B. Kroemer
Keyword(s):  
Large Scale ◽  
Intertemporal Choice ◽  
Subjective Evaluation ◽  
Brain Activation ◽  
Activation Patterns ◽  
Individual Level ◽  
The Individual ◽  
Global And Local ◽  
Main Effects ◽  
The Brain

AbstractTo cast valid predictions of future behavior or diagnose disorders, the reliable measurement of a “biomarker” such as the brain activation to prospective reward is a prerequisite. Surprisingly, only a small fraction of functional magnetic resonance imaging (fMRI) studies report or cite the reliability of brain activation maps involved in group analyses. Here, using simulations and exemplary longitudinal data of 126 healthy adolescents performing an intertemporal choice task, we demonstrate that reproducing a group activation map over time is not a sufficient indication of reliable measurements at the individual level. Instead, selecting regions based on significant main effects at the group level may yield estimates that fail to reliably capture individual variance in the subjective evaluation of an offer. Collectively, our results call for more attention on the reliability of supposed biomarkers at the level of the individual. Thus, caution is warranted in employing brain activation patterns prematurely for clinical applications such as diagnosis or tailored interventions before their reliability has been conclusively established by large-scale studies. To facilitate assessing and reporting of the reliability of fMRI contrasts in future studies, we provide a toolbox that incorporates common measures of global and local reliability.

scholarly journals Contextual moderators of the link between national and European identity among European youth

2017 ◽  
Author(s):  
Philipp Jugert ◽  
Jan Serek
Keyword(s):  
National Identity ◽  
European Identity ◽  
Individual Level ◽  
Positive Effects ◽  
Country Level ◽  
The Individual ◽  
Main Effects ◽  
The Relationship ◽  
European Youth ◽  
Contextual Moderators

Identification with Europe can constitute an important part of psychological citizenship for European citizens. From a self-categorization perspective, higher-order (e.g., with Europe) and lower order subgroup identities (e.g., with the nation) may interfere with each other if they are seen as incompatible. We were interested in contextual moderators at school and country level of youth' national identity on identification with Europe. We used multi-level regression analyses based on data from the International Civic and Citizenship Education Study (ICCS, 2009). Results showed strong positive effects of national identity at the individual, and classroom-level on European identity. However, main effects of national identity at the individual level were qualified by number of interactions with contextual-level measures of trust in the EU and indicators of social and economic inequality. Results point to the powerful effects of context in shaping the relationship between national and European identity.

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