Preferences for Attributes of Industrial Potatoes: An Empirical Investigation of the Swiss Market

Managing the transition from a commodity to a differentiated good in an increasingly liberalized, price-driven world is a challenge for Swiss producers of potatoes. To facilitate this process at the production level, knowledge about preferences in terms of product attributes is needed. We evaluate processor preferences regarding potato product attributes such as price and country of origin. Attributes are selected according to their influence on the buying decision of the processors. Additionally, we quantify the relative importance of product attributes for the main market segments chips, fries, and flakes. By applying a discreet-choice experiment with Bayesian estimation of individual part-worth utilities and randomized first-choice models for scenario analysis, we find that color, size and producer price determine 46% of the buying decision. However, while price is an important decision criterion, product and supplier criteria can be used to segment the market if the price premium is held within limits and size and color requirements are me

Enhancing Validity and Reliability Through Feedback-Driven Exploration: A Study in the Context of Conjoint Analysis

This study proposes a research design for the enhancement of validity and reliability in conjoint analysis research. For this purpose, we are applying the concept of feedback-driven exploration to conjoint analysis and assess the proposed research design concerning its benefits and limitations in respect of validity and reliability of results. The article is of interest for the field of preference elicitation through stated preference methods, and for model validation in transdisciplinary research. By applying the principle of feedback-driven exploration, we allow for feedback loops between researchers, industry experts and survey participants in order to strengthen both validity and reliability. A multi-case study of the agricultural markets in Switzerland illustrates the functioning of the proposed research design. We find that feedback-driven exploration significantly increases validity and reliability by enhancing methodological rigor and implementing an error-correcting mechanism. Additionally, a better understanding of the underlying decision processes is supported by the design due to increased interaction between researchers, industry experts and market participant

Preferences for Attributes of Industrial Potatoes: An Empirical Investigation of the Swiss Market

ISSN:1874-9380ISSN:0003-0589ISSN:1099-209

Enhancing Validity and Reliability Through Feedback-Driven Exploration: A Study in the Context of Conjoint Analysis

ISSN:1094-429XISSN:1573-929

Friedreich and dominant ataxias: Quantitative differences in cerebellar dysfunction measurements

Background: Sensitive outcome measures for clinical trials on cerebellar ataxias are lacking. Most cerebellar ataxias progress very slowly and quantitative measurements are required to evaluate cerebellar dysfunction. Methods: We evaluated two scales for rating cerebellar ataxias: the Composite Cerebellar Functional Severity (CCFS) Scale and Scale for the Assessment and Rating of Ataxia (SARA), in patients with spinocerebellar ataxia (SCA) and controls. We evaluated these scales for different diseases and investigated the factors governing the scores obtained. All patients were recruited prospectively. Results: There were 383 patients with Friedreich's ataxia (FRDA), 205 patients with SCA and 168 controls. In FRDA, 31% of the variance of cerebellar signs with the CCFS and 41% of that with SARA were explained by disease duration, age at onset and the shorter abnormal repeat in the FXN gene. Increases in CCFS and SARA scores per year were lower for FRDA than for SCA (CCFS index: 0.123±0.123 per year vs 0.163±0.179, P<0.001; SARA index: 1.5±1.2 vs 1.7±1.7, P<0.001), indicating slower cerebellar dysfunction indexes for FRDA than for SCA. Patients with SCA2 had higher CCFS scores than patients with SCA1 and SCA3, but similar SARA scores. Conclusions: Cerebellar dysfunction, as measured with the CCFS and SARA scales, was more severe in FRDA than in patients with SCA, but with lower progression indexes, within the limits of these types of indexes. Ceiling effects may occur at late stages, for both scales. The CCFS scale is rater-independent and could be used in a multicentre context, as it is simple, rapid and fully automated.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Biological and clinical characteristics of the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS) cohort: a cross-sectional analysis of baseline data

Background: Friedreich's ataxia is a rare autosomal recessive neurodegenerative disorder. Here we report cross-sectional baseline data to establish the biological and clinical characteristics for a prospective, international, European Friedreich's ataxia database registry. Methods: Within the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS) framework, we assessed a cohort of patients with genetically confirmed Friedreich's ataxia. The primary outcome measure was the Scale for the Assessment and Rating of Ataxia (SARA) and secondary outcome measures were the Inventory of Non-Ataxia Signs (INAS), the performance-based coordination test Spinocerebellar Ataxia Functional Index (SCAFI), the neurocognitive phonemic verbal fluency test, and two quality-of-life measures: the activities of daily living (ADL) part of the Friedreich's Ataxia Rating Scale and EQ-5D. The Friedreich's ataxia cohort was subdivided into three groups: early disease onset (≤14 years), intermediate onset (15-24 years), and late onset (≥25 years), which were compared for clinical characteristics and outcome measures. We used linear regression analysis to estimate the annual decline of clinical outcome measures based on disease duration. This study is registered with ClinicalTrials.gov, number NCT02069509. Findings: We enrolled 592 patients with genetically confirmed Friedreich's ataxia between Sept 15, 2010, and April 30, 2013, at 11 sites in seven European countries. Age of disease onset was inversely correlated with the number of GAA repeats in the frataxin (. FXN) gene: every 100 GAA repeats on the smaller repeat allele was associated with a 2·3 year (SE 0·2) earlier onset. Regression analyses showed significant estimated annual worsening of SARA (regression coefficient 0·86 points [SE 0·05], INAS (0·14 points [0·01]), SCAFI Z scores (-0·09 [0·01]), verbal fluency (-0·34 words [0·07]), and ADL (0·64 points [0·04]) during the first 25 years of disease; the regression slope for health-related quality-of-life state from EQ-5D was not significant (-0·33 points [0·18]). For SARA, the predicted annual rate of worsening was significantly higher in early-onset patients (n=354; 1·04 points [0·13]) and intermediate-onset patients (n=137; 1·17 points [0·22]) than in late-onset patients (n=100; 0·56 points [0·10]). Interpretation: The results of this cross-sectional baseline analysis of the EFACTS cohort suggest that earlier disease onset is associated with larger numbers of GAA repeats and more rapid disease progression. The differential estimated progression of ataxia symptoms related to age of onset have implications for the design of clinical trials in Friedreich's ataxia, for which SARA might be the most suitable measure to monitor disease progression. Funding: European Commission.SCOPUS: ar.jinfo:eu-repo/semantics/publishe