Missing data is a regular issue that researchers and practitioners must consider for treatment. Commonly, cases for which data is missing are excluded from inclusion in larger data sets. However, this is not the only option and could artificially alter the sample. Other options are available for imputing missing data. Expanding on work previously…

This essay describes Rasch analysis psychometric techniques and how such techniques can be used by life sciences education researchers to guide the development and use of surveys and tests. Specifically, Rasch techniques can be used to document and evaluate the measurement functioning of such instruments. Rasch techniques also allow researchers to…

Item response models typically assume that the item characteristic (step) curves follow a logistic or normal cumulative distribution function, which are strictly monotone functions of person test ability. Such assumptions can be overly-restrictive for real item response data. We propose a simple and more flexible Bayesian nonparametric IRT model…

Since many of the important energy-transferring pathways involve synthesis or degradation of biological macromolecules, observations of the enzymes responsible for starch breakdown provide a useful case study. Provides a short, one-step assay for the enzymes amylase and amyloglucosidase. Topics covered include goals, preparation, assay procedure,…

Recent international studies note that countries whose students perform well on international science assessments report the need to change science education. Some countries use assessments for diagnostic purposes to assist teachers in addressing their students' needs. However, in the United States, standards-based reform has focused the national…

Twelfth-grade students in Ohio who have passed all the sections of the ninth-grade proficiency tests take the twelfth-grade tests. Beginning in 1995-96, these tests will include science, although science will not become a factor in earning a diploma until the year 2000. This fact sheet provides information about the Twelfth-grade Proficiency Test…

Argues that data analysis problems can be used successfully in large introductory microbiology courses, even when exams consist entirely of multiple-choice questions and out-of-class contact with the instructor is limited. Discusses course organization, problem structure, student performance and response, advantages of using data analysis…