Modeling population and subject-specific growth in a latent trait measured by multiple instruments over time using a hierarchical Bayesian framework

Psychometric growth curve modeling techniques are used to describe a person’s latent ability and how that ability changes over time based on a specific measurement instrument. However, the same instrument cannot always be used over a period of time to measure that latent ability. This is often the case when measuring traits longitudinally in children. Reasons may be that over time some measurement tools that were difficult for young children become too easy as they age resulting in floor effects or ceiling effects or both. We propose a Bayesian hierarchical model for such a scenario. Within the Bayesian model we combine information from multiple instruments used at different age ranges and having different scoring schemes to examine growth in latent ability over time. The model includes between-subject variance and within-subject variance and does not require linking item specific difficulty between the measurement tools. The model’s utility is demonstrated on a study of language ability in children from ages one to ten who are hard of hearing where measurement tool specific growth and subject-specific growth are shown in addition to a group level latent growth curve comparing the hard of hearing children to children with normal hearing.KEYWORDS: Bayesian hierarchical models, psychometric modeling, language ability, growth curve modeling, longitudinal analysis     

Reading Skills in Children with Multichannel Cochlear-lmplant Experience

Forty children with prelingual, profound deafness who received the Nucleus multichannel cochlear implant between the ages of 2 and 13 years participated in this study. The children had an average of 63.3 months (SD=24 months) of experience with their cochlear implants. A majority of the children used simultaneous communication and attended public-school programs at the time of testing. Reading achievement was assessed using the Paragraph Comprehension subtest of the Woodcock Reading Mastery Test-Revised, Form G (1987). This study compared the reading-achievement levels of this group of cochlear-implant users with the results of previous studies of children with profound hearing losses who did not have the benefit of cochlear implants. Results indicated that nearly one half of the children in this study were reading at or within 8 months of their grade level. The reading-grade quotient of .74 was calculated based upon the slope of the regression line for the plot of years in school and reading grade-level achieved. This finding indicates that using a cochlear implant has a positive effect on reading achievement level.     

The effects of seasonal demand on depot location

Many of the cost functions associated with depot location algorithms assume an overall demand for a fixed period, usually one year. This paper describes an investigation into the effect of high seasonality within such demand figures on the optimal location of storage facilities. The preliminary results indicate that a more flexible approach for certain products could be worthwhile.     

Kindergarten oral language skill: A key variable in the intergenerational transmission of socioeconomic status

In this paper we test whether oral language development during the preschool years helps explain the positive relationship between family socioeconomic status (SES) and children's elementary school performance. In particular, we test for the portion of the SES effect on 2nd to 4th grade reading, 3rd to 4th grade mathematics, and overall teacher-rated performance that is explained by oral language ability measured when kindergarten begins. We analyze a unique data set containing unusually comprehensive measures of kindergarten oral language ability. The data are for white Midwestern children and their families. Estimation via structural equation modeling shows that oral language skill at kindergarten entry explains most of the effect of SES on elementary school performance. Since other studies have shown that elementary school performance strongly determines later educational attainment, much of the intergenerational transmission of socioeconomic status occurs when the child is very young.     

Marketing segmentation research—An application to bank services

The research reported here analyses data relating to bank services obtained by a stratified random sampling technique using stepwise linear regression and canonical correlation for the purpose of illustrating the application of segmentation principles to marketing research.