Keith Lehrer on Compatibilism

Keith Lehrer has been publishing on free will and compatiblism since 1960. Our concern here is to present an account of the development on his work on the subject.     

An analysis of U.S. parachuting fatalities: 2000-2004

Between 2000 and 2004, 125 recreational parachuting fatalities were reported in the USA. Each was categorized using a previously reported taxonomy. While patterns of skydiving fatality were largely unchanged since the last such analysis of fatalities from 1993-1999, some variations were noted. As in previous analyses, most of the recent skydiving fatalities were the direct result of human error. Some examples of commonplace human error fatalities were turning low to the ground resulting in a hard landing, accidentally colliding with other skydivers resulting in entangled parachutes, and failure to deploy the reserve parachute correctly in the event of malfunctioning main parachute.     

Verbal and cognitive distractors in driving performance while using hands-free phones

This study investigated the effect of different types of distractions related to use of a hands-free phone on driving performance. The study used three types of verbal distractors: casual conversation, simple arithmetic number guessing, and number adding, in the phone conversation. 12 adults were instructed to follow a lead vehicle on a closed-course highway in a fixed-based driving simulator. The results showed that use of a hands-free cellular phone involving verbal and cognitive distractions impaired driving performance and skill. Types of distraction produced significantly different effects on several dependent variables: the driving speed, headway (distance between the lead car and the manipulated car), brake reaction time, and number of collisions with the lead car. In general, the higher the cognitive load involved in the dialogue, the worse the driving performance.     

A General Family of Limited Information Goodness-of-Fit Statistics for Multinomial Data

Maydeu-Olivares and Joe (J. Am. Stat. Assoc. 100:1009–1020, 2005; Psychometrika 71:713–732, 2006) introduced classes of chi-square tests for (sparse) multidimensional multinomial data based on low-order marginal proportions. Our extension provides general conditions under which quadratic forms in linear functions of cell residuals are asymptotically chi-square. The new statistics need not be based on margins, and can be used for one-dimensional multinomials. We also provide theory that explains why limited information statistics have good power, regardless of sparseness. We show how quadratic-form statistics can be constructed that are more powerful than X ² and yet, have approximate chi-square null distribution in finite samples with large models. Examples with models for truncated count data and binary item response data are used to illustrate the theory.     

Religious Involvement among Caribbean Blacks in the United States

This study examined demographic and denominational differences in religious involvement (i.e., organizational, non-organizational, subjective) among Caribbean Blacks (Black Caribbeans) residing in the U.S. using data from the National Survey of American Life. Caribbean Blacks who were born in the U.S. had lower levels of religious involvement than those who immigrated and respondents originating from Haiti (as compared to Jamaica) had higher levels of religious involvement, while persons from Trinidad-Tobago reported lower service attendance than did Jamaicans. Older persons, women and married persons generally demonstrated greater religious involvement than their counterparts, while highly educated respondents expressed lower levels of self-rated religiosity. Denominational differences indicated that Baptists reported high levels of religious involvement; however, in several cases, Pentecostals and Seventh Day Adventists reported greater involvement.     

Assessing Approximate Fit in Categorical Data Analysis

A family of Root Mean Square Error of Approximation (RMSEA) statistics is proposed for assessing the goodness of approximation in discrete multivariate analysis with applications to item response theory (IRT) models. The family includes RMSEAs to assess the approximation up to any level of association of the discrete variables. Two members of this family are RMSEA₂, which uses up to bivariate moments, and the full information RMSEA_n. The RMSEA₂ is estimated using the M₂ statistic of Maydeu-Olivares and Joe (2005, 2006), whereas for maximum likelihood estimation, RMSEA_n is estimated using Pearson's X² statistic. Using IRT models, we provide cutoff criteria of adequate, good, and excellent fit using the RMSEA₂. When the data are ordinal, we find a strong linear relationship between the RMSEA₂ and the Standardized Root Mean Squared Residual goodness-of-fit index. We are unable to offer cutoff criteria for the RMSEA_n as its population values decrease as the number of variables and categories increase.