Diverse samples are valuable to the study of development, and to psychology more broadly. But convenience samples--typically recruited from local populations close to universities--are still the most widely used in developmental science, despite the fact that their use leads to a vast over-representation of Western, White, and high socio-economic…

Risks of life on the street caused by inclement weather, harassment, and assault threaten the unsheltered homeless population. We address some challenges of enumerating the street homeless population by testing a novel capture-recapture (CR) estimation approach that models individuals' intermittent daytime visibility. We tested walking and…

This research note examines respondent-nonrespondent bias in a statewide population survey. The findings indicate general support for using master lists in the selection of respondents for participation in a large mail questionnaire survey. Two papers follow which react to this information. (Author/CT)

Problems of definition in estimation in evaluation research were studied through a survey of homeless persons in Cook County (Illinois) based on 481 interviews. Differences arising from the following four population definitions are presented: (1) traditional homeless; (2) marginally housed; (3) social isolates; and (4) total of these categories.…

Two basic methods exist for drawing probability samples to be used in telephone surveys: directory sampling (from alphabetical or street directories) and random digit dialing (RDD). RDD includes unlisted numbers, whereas directory sampling includes only listed numbers. The goal of this paper is to estimate the effect of failure to include…

The utility of the biomedical model of adjusted statistics is demonstrated. The model is recommended for use by educational researchers to randomize subjects for a more accurate estimate of school programs' success or failure when compared across classrooms or other units. (Author/MH)