The development in information science has enabled an explosive growth of data, which attracts more and more researchers to engage in the field of big data analytics. Noticeably, in many real-world applications, large amounts of data are imbalanced data since the events of interests occur infrequently. Classification of imbalanced data is an…

Presents a method for the collection and analysis of collateral data about research subjects (i.e., measurements of events in subjects' lives that may affect outcome measures and/or lead to attrition). A six-step procedure evaluates bias resulting from subject attrition from a study using data from lost and retained subjects. (SLD)

In the educational literature, responses to surveys commonly serve as the source of data for many empirical articles. Whenever a survey is used as a source of data, the response rate can greatly affect the potential generalizability of the findings. Using Monte Carlo methods, this study examined the effects on sample estimates of the population…

Possible bias due to sampling problems or low response rates has been a troubling "nuisance" variable in empirical research since seminal and classical studies were done on these problems at the beginning of this century. Recent research suggests that: (1) earlier views of the alleged bias problem were misleading; (2) under a variety of fairly…

Meta-analysis of Title I program evaluations shows the norm-referenced model overestimates positive effectiveness; while the regression-discontinuity design underestimates it. Potential biases include residual regression artifacts, attrition and time-of-testing problems in the norm-referenced design, and assignment, measurement, and data…

Purpose: In this study the levels of staff turnover reported in the nursing home literature (1990-2003) are reviewed, as well as the definitions of turnover used in these prior studies. With the use of primary data collected from 354 facilities, the study addresses the various degrees of bias that result, depending on how staff turnover is defined…

Some students are excluded from the National Education Longitudinal Study of 1988 (NELS:88) because of an inability, whether due to physical, mental, or linguistic barriers, to participate in studies requiring questionnaire or cognitive test completion. The implications of this exclusion for sample representativeness, national estimation, and…

The National Household Education Survey (NHES) was conducted for the first time in 1991 to collect data on the early childhood education (ECE) experiences of young children and participation in adult education. Because the NHES methodology is relatively new, field tests were necessary. A large field test of approximately 15,000 households was…

A general interest in attrition, or loss of units from a study, stems in part from the observation that the infrequency of attention to attrition exacerbates problems of data interpretation. As a substudy of the national evaluation of Project Follow Through, the potential biasing effects of attrition of subjects from the sites were investigated.…

The extent to which students with disabilities are represented in national data collection programs was investigated by reviewing nine such programs that are receiving attention in current educational reform initiatives. Results suggest that 40-50% of students with disabilities are excluded from these prominent data collection programs. (SLD)

Structural equation models incorporating unmeasured variables make possible the rigorous testing of theories previously difficult to test adequately because of fallible measures of the theoretic variables. This paper first discusses a simple causal model; incorporating a single unmeasured variable for the purpose of exposition. A substantive…

Longitudinal studies conducted with children typically experience non-response problems that can make substantial inroads on sample size and introduce bias into the analysis. Three methods for limiting non-response in school-based research programs were assessed: (1) asking parents to return consent forms only if they do not want their children to…