Assesses techniques used by researchers to collect and analyze data on how people with visual impairments or blindness learn, understand, and think about geographic space. Recommendations are made for increasing the validity of studies, including the use of multiple, mutually supportive tests; larger samples; and real-world environments.…

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…

Approximately 6,500 children are enrolled per year in the New York State Experimental Prekindergarten Program (PreK). In 1975-76 a longitudinal study was begun to determine the program's impact on the development of children while enrolled in the program and in the primary grades. Samples from a population of 5,245 four-year-old prekindergarten…