In psychological and survey research, the prevalence and serious consequences of careless responses from unmotivated participants are well known. In this study, we propose to iteratively detect careless responders and cleanse the data by removing their responses. The careless responders are detected using person-fit statistics. In two simulation…

Increasingly students, particularly those in the social sciences, work with survey data collected through a more complex sampling method than a simple random sample. Failing to understand how to properly approach survey data can lead to inaccurate results. In this article, we describe a series of online data visualization applications and…

This study serves as a teaching aid for teachers of introductory statistics. The aim of this study was limited to determining various sample sizes when estimating population proportion. Tables on sample sizes were generated using a C[superscript ++] program, which depends on population size, degree of precision or error level, and confidence…

In 1988, the National Center for Education Statistics (NCES) introduced a proposal to develop a private school data collection that would improve on the sporadic collection of private school data dating back to 1890 and improve on commercially available private school sampling frames. Since 1989, the U.S. Bureau of the Census has conducted the…

The National Center for Education Statistics collects data on crime and violence in U.S. public schools through the School Survey on Crime and Safety (SSOCS). This First Look report presents findings from the 2009-10 School Survey on Crime and Safety data collection. Developed and managed by the National Center for Education Statistics (NCES)…

Oversampling and cluster sampling must be addressed when analyzing complex sample data. This study: (a) compares parameter estimates when applying weights versus not applying weights; (b) examines subset selection issues; (c) compares results when using standard statistical software (SPSS) versus specialized software (AM); and (d) offers…

This activity makes students a part of an investigation that determines the frequency of a particular plant variety in a simulated population. Provides an opportunity for students to observe the inherent variability of estimates, observe the relationship between sample size and sampling error, and consider aspects of research design. (Author/SAH)

The purpose of this survey was to identify the statistics texts most frequently used by psychology departments and to see if a typical survey of textbooks used by a partial sample of psychology departments would be accurate in describing the entire sample of departments. Partial returns resulted in a meaningful error. (RM)

In true experiments in which sample material can be randomly assigned to treatment conditions, most researchers presume that the condition of equal sample sizes is statistically desirable. When one or more a priori contrasts can be identified which represent a few overriding experimental concerns, however, allocating sample material unequally will…

This self-instructional manual for psychological assessment focuses on the following topics: (1) general statistics, (2) central tendency, (3) random, continuous, and discrete variables, (4) variability, (5) measuring variability, (6) sampling, (7) derived scores, (8) covariation, (9) reliability and validity, and (10) standard error of…

With the help of widely available microcomputers, it is possible to demonstrate certain statistical phenomena which students of statistics are usually expected to take on faith. Two demonstrations are described. In the first demonstration, three common types of sampling (simple random, biased, and stratified-random) are used to compare statistics…

Abuses and misuses of statistics are frequent. This digest attempts to warn against these in three broad classes of pitfalls: sources of bias, errors of methodology, and misinterpretation of results. Sources of bias are conditions or circumstances that affect the external validity of statistical results. In order for a researcher to make…