Modeling the effects of including/excluding attributes in choice experiments on systematic and random components

This paper examines the impact of attribute presence/absence in choice experiments using covariance heterogeneity models and random coefficient models. Results show that attribute presence/absence impacts both mean utility (systematic components) and choice variability (random components). Biased mean effects can occur by not accounting for choice variability. Further, even if one accounts for choice variability, attribute effects can differ because of attribute presence/absence. Managers who use choice experiments to study product changes or new variants should be cautious about excluding potentially essential attributes. Although including more relevant attributes increases choice variability, it also reduces bias. © 2007 Elsevier B.V. All rights reserved

The importance of social product attributes in consumer purchasing decisions: A multi-country comparative study

This paper examines the role that social attributes-environmental and labour conditions-play in product choice across a range of developed and emerging economies. We use a multi-attribute design to force consumers to not only trade-off social attributes with tangible attributes but also make trade-offs with other intangible attributes, namely brand and country of origin. Our results show that: (1) social attributes are generally more influential in developed than in emerging economies, (2) the importance of social attributes holds across high and low involvement products, and (3) social attributes can influence product choice even when other intangible attributes are included in the design. We believe that our results offer a more accurate picture of the role of social attributes since they are based on a multi-cue, multi-product design that forced consumers to make tradeoffs between tangible and intangible attributes. © 2009 Elsevier Ltd. All rights reserved

Museum Visitors Care about Everything! Using Best-Worst Scaling for Strategic Focus

Museums face similar challenges to those encountered by managers of fast-moving consumer goods. For instance, both must determine what things (factors) attract consumers (visitors) to their products (museums). Several methodologies have been applied in this area to find out what matters to visitors. In general, these methods produce lengthy lists and do not discriminate between items in terms of relative positioning. In this paper, we explore the use of best-worst scaling (BWS) to reduce and to quantify factors in their order of impact or importance. BWS is simple to use, producing results that are easy to communicate to nontechnical audiences, fostering links between research and actionable implications. We use an example with museum visitors to provide insights into the applicability of this technique to the arts sector, its limitations and areas for further research

Overcoming challenges and improvements in best-worst elicitation: Determining what matters to Japanese wheat millers

Knowing how to produce what types of wheat with what characteristics and in what quantities is a key challenge for producer countries like Australia to successfully export wheat to various markets that consume it. Both producers and consumers would benefit by better matching what is produced to what the market(s) prefer and are willing to pay to have produced. Analysis of decision-maker choices is difficult as there are only a small number of millers in any one country that make buying decisions. Moreover, the buyers tend to use an extensive list of quality characteristics to inform their purchases. This research provides details of some of the insights that have been gained into this decision making context using best-worst scaling (BWS), as a choice-based measurement and modelling approach. The survey instrument was administered using CAPI in personal interviews with Japanese flour millers. A small number of flour millers in Japan supply the entire government regulated market with products like Udon and Ramen noodles. Face-to-face interviews were conducted with 14 individuals from four different companies that account for about 74 per cent of wheat flour production in Japan. These individuals play various roles in wheat buying, production, distribution and marketing, such as production managers, quality control specialists and new product and scientific development managers. Based on the literature and pilot discussions with wheat buyers, a list was compiled of 31 factors (attributes) that could be considered by the individuals who influence wheat buying decisions. These included technical attributes (e.g., viscograph peak height; farinograph dough stability, etc) as well as attributes common in most business-to-business trade settings that are often cited as important in many agricultural trade contexts (e.g., price; country of origin; uniformity of shipment, etc)

The scale-adusted latent class model: Application to museum visitation

© 2010 Cognizant Comm. Corp. Preferences of tourists and visitors are varied in a number of markets, making it difficult for managers to understand how underlying segments might respond to changes in service offerings. Market segments differ in preferences for specific features, as well as how consistently they make their choices. In this article, we illustrate recent developments in choice modeling that allows for simultaneously modeling feature preferences and consistency of choice. We use the Scale-Adjusted Latent Class Model (SALCM) to better understand choices in the context of a research project conducted in collaboration with six major Australian museums involving a sample of 3,685 museum visitors. We identify three preference classes of museum-goers that explain preferences for levels of 26 museum attributes: Life Force (two thirds of visitors), Educated Thinkers, and Wealthy At-Homes. Our results indicate sensitivity to general entry prices, including preference for free entry or entry "by donation." Tours are preferred if smaller, lengthier, and conducted by paid museum staff. Not unexpectedly, the findings suggest that museums should cater for children, with some classes responding positively to providing supervised child areas. Most visitors prefer museums that are dynamic, offer new experiences, and regularly update permanent displays. However, the three classes identified have different overall experience preferences; for example, Educated Thinkers see museums as an educational opportunity, but Wealthy At-Homes prefer entertaining experiences. Incentives for return visits and cross-museum promotional offers are valued by the Life Force class, but have little effect on Educated Thinkers. The SALCM approach may be attractive to other areas of tourism analysis, especially where offerings contain many attributes and potential market segments are difficult to define and understand

Automatic extraction of candidate nomenclature terms using the doublet method

BACKGROUND: New terminology continuously enters the biomedical literature. How can curators identify new terms that can be added to existing nomenclatures? The most direct method, and one that has served well, involves reading the current literature. The scholarly curator adds new terms as they are encountered. Present-day scholars are severely challenged by the enormous volume of biomedical literature. Curators of medical nomenclatures need computational assistance if they hope to keep their terminologies current. The purpose of this paper is to describe a method of rapidly extracting new, candidate terms from huge volumes of biomedical text. The resulting lists of terms can be quickly reviewed by curators and added to nomenclatures, if appropriate. The candidate term extractor uses a variation of the previously described doublet coding method. The algorithm, which operates on virtually any nomenclature, derives from the observation that most terms within a knowledge domain are composed entirely of word combinations found in other terms from the same knowledge domain. Terms can be expressed as sequences of overlapping word doublets that have more specific meaning than the individual words that compose the term. The algorithm parses through text, finding contiguous sequences of word doublets that are known to occur somewhere in the reference nomenclature. When a sequence of matching word doublets is encountered, it is compared with whole terms already included in the nomenclature. If the doublet sequence is not already in the nomenclature, it is extracted as a candidate new term. Candidate new terms can be reviewed by a curator to determine if they should be added to the nomenclature. An implementation of the algorithm is demonstrated, using a corpus of published abstracts obtained through the National Library of Medicine's PubMed query service and using "The developmental lineage classification and taxonomy of neoplasms" as a reference nomenclature. RESULTS: A 31+ Megabyte corpus of pathology journal abstracts was parsed using the doublet extraction method. This corpus consisted of 4,289 records, each containing an abstract title. The total number of words included in the abstract titles was 50,547. New candidate terms for the nomenclature were automatically extracted from the titles of abstracts in the corpus. Total execution time on a desktop computer with CPU speed of 2.79 GHz was 2 seconds. The resulting output consisted of 313 new candidate terms, each consisting of concatenated doublets found in the reference nomenclature. Human review of the 313 candidate terms yielded a list of 285 terms approved by a curator. A final automatic extraction of duplicate terms yielded a final list of 222 new terms (71% of the original 313 extracted candidate terms) that could be added to the reference nomenclature. CONCLUSION: The doublet method for automatically extracting candidate nomenclature terms can be used to quickly find new terms from vast amounts of text. The method can be immediately adapted for virtually any text and any nomenclature. An implementation of the algorithm, in the Perl programming language, is provided with this article

Isolation of polymorphic microsatellites in the stemless thistle (Cirsium acaule) and their utility in other Cirsium species

The genus Cirsium includes species with both widespread and restricted geographical distributions, several of which are serious weeds. Nine polymorphic microsatellite loci were isolated from the stemless thistle Cirsium acaule. Eight were polymorphic in C. acaule, six in C. arvense and seven in C. heterophyllum. One locus monomorphic in C. acaule showed polymorphism in C. heterophyllum. The mean number of alleles per locus was 4.1 in C. acaule, 6.2 in C. arvense and 2.9 in C. heterophyllum. These nine loci were also amplified in C. eriophorum and C. vulgare, suggesting that these markers may be of use throughout the genus

Muscle Glycogen Utilisation during an Australian Rules Football Game.

PURPOSE: To better understand the carbohydrate (CHO) requirement of Australian Football (AF) match play by quantifying muscle glycogen utilisation during an in-season AF match. METHODS: After a 24 h CHO loading protocol of 8 g/kg and 2 g/kg in the pre-match meal, two elite male forward players had biopsies sampled from m. vastus lateralis before and after participation in a South Australian Football League game. Player A (87.2kg) consumed water only during match play whereas player B (87.6kg) consumed 88 g CHO via CHO gels. External load was quantified using global positioning system technology. RESULTS: Player A completed more minutes on the ground (115 vs. 98 min) and covered greater total distance (12.2 vs. 11.2 km) than Player B, though with similar high-speed running (837 vs. 1070 m) and sprinting (135 vs. 138 m), respectively. Muscle glycogen decreased by 66% in Player A (Pre-: 656, Post-: 223 mmol∙kg-1 dw) and 24% in Player B (Pre-: 544, Post-: 416 mmol∙kg-1 dw), respectively. CONCLUSION: Pre-match CHO loading elevated muscle glycogen concentrations (i.e. >500 mmol.kg-1 dw), the magnitude of which appears sufficient to meet the metabolic demands of elite AF match play. The glycogen cost of AF match play may be greater than soccer and rugby and CHO feeding may also spare muscle glycogen use. Further studies using larger sample sizes are now required to quantify the inter-individual variability of glycogen cost of match play (including muscle and fibre-type specific responses) as well examine potential metabolic and ergogenic effects of CHO feeding

Synchronous presentation of acute acalculous cholecystitis and appendicitis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Acute acalculous cholecystitis is traditionally associated with elderly or critically ill patients.</p> <p>Case presentation</p> <p>We present the case of an otherwise healthy 23-year-old Caucasian man who presented with acute right-sided abdominal pain. An ultrasound examination revealed evidence of acute acalculous cholecystitis. A laparoscopy was undertaken and the dual pathologies of acute acalculous cholecystitis and acute appendicitis were discovered and a laparoscopic cholecystectomy and appendectomy were performed.</p> <p>Conclusion</p> <p>Acute acalculous cholecystitis is a rare clinical entity in young, healthy patients and this report describes the unusual association of acute acalculous cholecystitis and appendicitis. A single stage combined laparoscopic appendectomy and cholecystectomy is an effective treatment modality.</p