Purpose: Children from low--socioeconomic status families often perform poorly on standardized vocabulary assessments. The primary purpose of the study was to determine whether lexical diversity as measured by "D" (Malvern, Richards, Chipere, & Durán, 2004) serves as a valid measure of vocabulary in at-risk, low-income, predominantly…

The purpose of this study is to develop an achievement test which includes the basic concepts about the subject of sound and its properties in middle school science lessons and which at the same time aims to reveal the alternative concepts that the students already have. During the process of the development of the test, studies in the field and…