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Other Presentations

World
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 Presentations: US
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| Annual Statistical Modeling Week |
Annual conference featuring applications-oriented seminars focusing on the latest trends in statistical analysis.
| 2007 Sawtooth Software Conference |
October 15-19, 2007, Hyatt Vineyard Creek Hotel and Spa, Santa Rosa, CA.
SI Presentation, Wednesday, October 17:
Removing the Scale Factor Confound in Multinomial Logit Choice Models to Obtain Better Estimates of Preference,
Jay Magidson, Jeroen Vermunt
A theoretical weakness of CBC as currently practiced is that individual
utility estimates are confounded by differential measures of uncertainty (error variances). By separating the scale factor from the utilities we obtain clearer estimates of preference. Results from extended latent class models indicate that quick respondents have the highest variances.
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| | Joint Annual Meeting of the Interface and the Classification Society of North America |
June 8-12, 2005, Washington University School of Medicine, St. Louis, MO.
SI Short Course, Wednesday, June 8, 1-4pm:
Latent Class Models for Clustering and Classification, Jay Magidson and Anthony Babinec
Download the Abstract
| | 16th Annual Advanced Research Techniques FORUM |
June 12-15, 2005, Coeur d'Alene Resort, Idaho.
SI Short Course, Monday, June 13, 3-3:30pm:
Using Parsimonious Conjoint and Choice Models to Improve the Accuracy of Out-of-Sample Share Predictions, Jay Magidson, Jeroen Vermunt and Thomas Eagle
A primary benefit of conjoint and choice models is the availability of a simulator to generate predictions of ratings and/or market share for new products based on estimated part-worth utilities.
To the extent to which the estimated utilities are based on an over-fitted, over-parameterized model, such predictions may not validate outside the sample. In this session we introduce new models that
posit continuous factors (C-Factors) underlying the part worth utility parameters to account for respondent heterogeneity and show that they are much simpler to estimate and easier to interpret than HB models.
We use data from a rating-based conjoint and from a choice/ranking study to compare various HB, C-Factor, latent class and hybrid models with respect to over-fitting. The results suggest that new hybrid models containing
both latent classes and C-Factors can be used to obtain segments and improve the accuracy of out-of-sample predictions.
| 2004 Sawtooth Software Conference |
October 6-8, 2004, Shelter Pointe Hotel and Marina, San Diego, CA.
SI Presentation, Tuesday, October 5:
APPLICATIONS IN SEGMENTATION MODELING USING LATENT GOLD, GOLDMineR, SI-CHAID, AND LATENT GOLD CHOICE
Segmentation modeling is a statistical approach for identifying and describing market segments. Depending upon the type of application, different approaches are available. In this tutorial, emphasizing methodological and practical issues of model building, we use commercially available software packages to illustrate four approaches:
Latent class (LC) models. LC/finite mixture models provide powerful ways to obtain segments based on multiple criteria such as 1) ratings/rankings/choices obtained from conjoint studies, or 2) in general clustering applications. Compared to Hierarchical Bayes (HB) models, individual level predictions are of comparable validity, but LC models are much quicker and easier to estimate, and segments are obtained directly as part of the model. (Latent GOLD and LG Choice will be used).
CHAID models. CHAID (Chi-Squared Automatic Interaction Detection) is a tree-based segmentation technique effective in obtaining meaningful segments that differ with respect to a single categorical criterion variable such as response to a mailing. (SI-CHAID, the successor to our original SPSS CHAID program, will be used).
Regression models. In cases where a single criterion such as profitability is available, a regression approach is often a good way to identify the best (most profitable) segments. (The ordinal logit program GOLDMineR will be used here and the resulting segments will be compared to those obtained from CHAID).
Hybrid models. We describe an LC
hybrid alternative that maintains the simple structure
of a CHAID or regression model, but may be used to
obtain segments that are predictive across multiple
criteria. We illustrate this in a discrete choice
study.
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| 2004 Meeting of the International Federation of Classification Societies
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July 15-18, 2004, Illinois Institute of Technology, Chicago, IL.
Short Course: Latent Class Models for Clustering and Classification; Jay Magidson & Tony Babinec
Presentation Abstract: Latent Class Models for Clustering and Classification
The various uses of latent class and finite mixture models for clustering and classification are growing rapidly because of:
- the lack of restrictive
assumptions underlying the general model,
- major developments in
maximum likelihood estimation of these models, and
- availability of model parameters to use for classifying new cases.
This short course introduces the latent class (LC) and finite mixture approach to clustering and focuses on three important LC models -- cluster, factor, and regression -- for combinations of nominal, ordinal, and/or continuous variables. Applications are taken from the fields of marketing research and the biomedical sciences. Topics include (1) relationship to and improvements over K-means clustering, (2) use of simultaneous cluster and regression/discriminant/choice analyses as an improvement over the traditional tandem cluster-regression analyses, and (3) use of covariates and an extended CHAID algorithm to describe the resulting latent class segments. We will provide extensive references and a description of the major latent class modeling software available. The Latent GOLD program and new Latent GOLD Choice module will be used for illustration.
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E-mail Contact: will@statisticalinnovations.com
Address:
Statistical Innovations,
375 Concord Avenue,
Belmont, MA 02478-3084
Phone: +1.617.489.4490
Fax: +1.617.489.4499
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