The questions posed by life course researchers often differ in fundamental ways from those posed by sociologists, developmental psychologists, or economists (Elder, 1998; Mayer & Tuma, 1990). For example, life course researchers often focus analytic attention on transitions marking adolescence or early adulthood and the roles and statuses accompanying such transitions (Hogan & Astone, 1986; Mod...

"This paper will investigate the issue of weighting for panel attrition in event-history models by comparing alternative treatments of sampling weights in a divorce model for members of the 1986 [U.S.] Survey of Income and Program Participation (SIPP). Three distinct weighting procedures are compared. These are based on (1) the initial selection probability weights; (2) the 1986 SIPP panel weig...

A compact graphical device for combining survival and time-varying covariate information is proposed. The proposed graph contains the Kaplan-Meier estimator for right-censored data and a simultaneous display of the behaviour of time-dependent covariate(s) and the lifetime for each subject in the sample. The observed levels of time-dependent covariates are possibly subjected to an initial dimens...

This study uses a modeling technique often used in economics and other disciplines but rarely applied to educational research. The technique, known as event history modeling, is used to examine the temporal dimensions of student departure from a large research university. This approach allows researchers to remedy analytic problems often found when standard statistical procedures are used to st...

Basic Problem: Heterogeneity What is it? Usually thought of as unmeasured risk factors. Can be induced when a relevant covariate is not included in the model’s specification. Maybe these factors are not measured (unmeasureable?) or are unknown to exist. Heterogeneity can lead to trouble insofar as parameter estimates can be inconsistent, standard errors can be wrong, and estimates of duration d...

Event timeline serves as the basic structure of history, and it is used as a disposition of key phenomena in studying history as a subject in secondary school. In order to enable a student to understand a historical phenomenon as a series of connected events, we present a system for automatic event timeline generation from history textbooks. Additionally, we propose Message Sequence Chart (MSC)...

The personal and financial infor­ mation of some University donors may be at risk after an unknown i n t r u d e r h a c k e d in to a Development Office server Jan. 13 — th e f i r s t c o m p u te r s e c u r i ty breach of its magnitude at Notre D am e, U nivers ity officials said Sunday. The data in question — possibly including Social Security numbers, credit card information and check im ...