¹For more information on the NPSAS survey, consult the methodology reports for each survey: U.S. Department of Education, National Center for Education Statistics, Methodology Report for the 1990 National Postsecondary Student Aid Study (NCES 92–080) (Washington, DC: 1992), Methodology Report for the National Postsecondary Student Aid Study, 1992–93 (NCES 95–211) (Washington, DC: 1995), National Postsecondary Student Aid Study, 1995–96 (NPSAS:96), Methodology Report (NCES 98–073) (Washington, DC: 1997), and National Postsecondary Student Aid Study, 1999–2000 (NPSAS:2000), Methodology Report (NCES 2002–152) (Washington, DC: 2002). Additional information is also available at the NPSAS website. (return to text)

²U.S. Department of Education, National Center for Education Statistics, Methodology Report for the 1990 National Postsecondary Student Aid Study (NCES 92–080) (Washington, DC: 1992). (return to text)

_³U.S. Department of Education, National Center for Education Statistics, Methodology Report for the National Postsecondary Student Aid Study, 1992–93 (NCES 95–211) (Washington, DC: 1995). (return to text)

_⁴U.S. Department of Education, National Center for Education Statistics, National Postsecondary Student Aid Study, 1995–96 (NPSAS:96), Methodology Report (NCES 98–073) (Washington, DC: 1997) (return to text)

⁵U.S. Department of Education, National Center for Education Statistics, National Postsecondary Student Aid Study, 1999–2000 (NPSAS:2000), Methodology Report (NCES 2002–152) (Washington, DC: 2002). (return to text)

⁶For nonresponse bias analysis, see U.S. Department of Education, National Center for Education Statistics, National Postsecondary Student Aid Study, 1999–2000 (NPSAS:2000), CATI Nonresponse Bias Analysis Report (NCES 2002–03) (Washington, DC: 2002). (return to text)

⁷The NPSAS samples are not simple random samples, and therefore, simple random sample techniques for estimating sampling error cannot be applied to these data. The DAS takes into account the complexity of the sampling procedures and calculates standard errors appropriate for such samples. The method for computing sampling errors used by the DAS involves approximating the estimator by the linear terms of a Taylor series expansion. The procedure is typically referred to as the Taylor series method. (return to text)

⁸A Type I error occurs when one concludes that a difference observed in a sample reflects a true difference in the population from which the sample was drawn, when no such difference is present. (return to text)

⁹U.S. Department of Education, National Center for Education Statistics, A Note from the Chief Statistician, no. 2, 1993.(return to text)

¹⁰Ibid.(return to text)