Achievement tests are commonly used in education to evaluate students' academic performance and proficiency in specific subject areas. However, there is a major problem that threatens the validity of achievement test scores which is test-taking disengagement. Respondents provide answers that are inconsistent with their true ability level and can…

Many low-stakes assessments, such as international large-scale surveys, are administered during time-limited testing sessions and some test-takers are not able to endorse the last items of the test, resulting in not-reached (NR) items. However, because the test has no consequence for the respondents, these NR items can also stem from quitting the…

While the significance of principals' roles is widely recognized, and the impactful behaviors of principals are empirically delineated, little is known about whether principals spend time in an impactful way, whether principals' time use varies across different school contexts, or whether principals' time use is related to critical school…

Scientific literacy is a central aim of science education. The "Programme for International Student Assessment" (PISA) provides a measure of secondary students' scientific literacy and reported science instruction in 72 countries. Researchers have analyzed PISA data to identify important relationships between science instruction and…