Epidemiologists frequently encounter studies with ordered responses. Standard ordered response logit models, such as the continuation ratio model, constrain exposure to have a homogeneous effect across thresholds of the ordered response. We demonstrate a method for fitting regression models for unconstrained, partially or fully constrained continuation odds ratios using a 'person-threshold' dat...

BACKGROUND To estimate a threshold limit value for a compound known to have harmful health effects, an 'elbow' threshold model is usually applied. We are interested on non-parametric flexible alternatives. METHODS We describe how a step function model fitted by isotonic regression can be used to estimate threshold limit values. This method returns a set of candidate locations, and we discuss ...

in this research, 6517 records, collected by khojir sheep breeding station (tehran, iran), during 1991 to 2011 were used to estimate genetic parameters of lamb survival in zandi sheep. genetic parameters were estimated using 16 different models of animal model, sire and threshold models using reml procedures. the aic criterion was used to evaluate the models. the effects in the most suitable an...

Background. Imagery ability is one of the most potent factors influencing imagery effectiveness. Therefore, prior to imagery training, it is important to assess the participant’s imagery ability, typically using a self-report questionnaire. Objectives. This study examined the factorial validity and internal consistency of the Malaysian adapted SIAQ using confirmatory factor analysis and Cronba...

The aim of this study is to examine the nonlinear effects of fiscal and monetary policies on inflation during 1990:3 to 2013:1 based on threshold model. First lag of the liquidity growth is recognized as threshold variable with threshold value estimated at 6.37 percent. In low liquidity growth, the results indicate that inflation expectations and the lagged liquidity growth are the most importa...

A formalization of the Threshold Theory, called the Probabilistic Threshold Model, is introduced. According to the Threshold Theory semantic categorization decisions come about through the placement of a threshold criterion along a dimension that represents items’ similarity to the category representation. The adequacy of this theory is assessed by applying the Probabilistic Threshold Model to ...