Ranked preference data arise when a set of judges rank, in order of their preference, a set of objects. Such data arise in preferential voting systems and market research…
Ranked preference data arise when a set of judges rank, in order of their preference, a set of objects. Such data arise in preferential voting systems and market research surveys. Covariate data associated with the judges are also often recorded. Such covariate data should be used in conjunction with preference data when drawing inferences about judges.
To cluster a population of judges, the population is modeled as a collection of homogeneous groups. The Plackett-Luce model for ranked data is employed to model a judge's ranked preferences within a group. A mixture of Plackett- Luce models is employed to model the population of judges, where each component in the mixture represents a group of judges.
Mixture of experts models provide a framework in which covariates are included in mixture models. Covariates are included through the mixing proportions and the component density parameters. A mixture of experts model for ranked preference data is developed by combining a mixture of experts model and a mixture of Plackett-Luce models. Particular attention is given to the manner in which covariates enter the model. The mixing proportions and group specific parameters are potentially dependent on covariates. Model selection procedures are employed to choose optimal models.
Model parameters are estimated via the ‘EMM algorithm’, a hybrid of the expectation–maximization and the minorization–maximization algorithms. Examples are provided through a menu survey and through Irish election data. Results indicate mixture modeling using covariates is insightful when examining a population of judges who express preferences.
This chapter presents the personal perspectives of the author on issues related to methodology in teaching children with learning disabilities and to the role of…
This chapter presents the personal perspectives of the author on issues related to methodology in teaching children with learning disabilities and to the role of methodology in the Individuals with Disabilities Education Act (IDEA). Additionally, problems schools have had in implementing IDEA are highlighted and proposals offered to alleviate those difficulties.
I WAS lunching recently with a friend who reckons he has about ten more years to go in libraries before retirement, and he raised an interesting question. Given the realisation that one will not, at his age, now be likely to make chief, what can a senior and experienced librarian do by way of interesting alternative to just serving out time?
The purpose of this study was to identify those factors that are supposed to be the most important in terms of small business success in tourism industry. The empirical…
The purpose of this study was to identify those factors that are supposed to be the most important in terms of small business success in tourism industry. The empirical data is collected within one region in Finland. The respondents were asked to evaluate the importance of the given factors for the firm's success and how highly the respondent evaluated the company's expertise in each factor in their operations. Questionnaires were sent by mail to a total of 214 tourism businesses. The final response rate was 43% (92 businesses). According to the analysis of the data, the respondents emphasise the importance of customer orientation, good skills in leadership, internal marketing and a good reputation of the firm and the product. The impact of external advice (incubators, consultants, research organisations) was evaluated as the least important factor of success. So, market orientation seems to play a key role in the performance of small and micro tourism firms. Customer orientation is also well mastered according to the businesses. The greatest development needs would be in the areas of price and accessibility, as well as in customer orientation. The results of this study indicate that there are no statistically significant differences in the views held by slowly or fast growing tourism businesses regarding the importance of the success factors. The same factors are considered important and less important in both slowly and fast growing businesses. Neither were there any statistically significant differences in these businesses as to the expertise in these success factors.
The following is an introductory profile of the fastest growing firms over the three-year period of the study listed by corporate reputation ranking order. The business activities in which the firms are engaged are outlined to provide background information for the reader.