Petrography lower if wholly or partly vitreous. The specific gravity of the more common rocks range from about 2.5 to 3.2. Archaeologists use petrography to identify mineral components in pottery. This information ties the artifacts to geological areas where the raw materials for the pottery were obtained. In addition to clay, potters often used rock fragments, usually called "temper" or "aplastics", to modify the clay's properties. The geological information obtained from the pottery components provides insight into how potters selected and used local and non-local resources. Archaeologists are able to determine whether pottery found in a particular location was locally produced
Empirical study of literature when it is concerned with questions of reading. In these two areas research and studies based on the framework are steadily growing. Further fields where the framework in various revised and expanded versions attracts scholarship is (comparative) cultural studies and pedagogy. One of several dictionary definitions of the field is as follows: “Movement within the study of literature concerned with the study of literature as a social system of [inter]actions. The main question is what happens to literature: it is written, published, distributed, read, censored, imitated, etc. The empirical study of literature originated as a reaction to, and an attempt