An Examination of Test Score Trajectories Around School Switching Due to Grade Configuration

Do grade configurations affect student academic performance? To bring new evidence to this question, I use recent district-by-grade data for nearly the entire United States which contain measures of test score achievement and rates of school switching induced by grade configuration. Past research has found that student performance is on average relatively low following switches due to grade configuration, but in fact students perform relatively better in the grades just prior to these switches. In the national data, I find that this so-called “top dog/bottom dog” pattern appears for all terminal grade choices among grades 3 through 8, is geographically widespread, and is robust to controlling for grade-specific effects of a rich set of covariates. Thus I establish that the top dog/bottom dog pattern is a very pervasive phenomenon in American education. I explore potential mechanisms and discuss policy and research implications.

Measures to Control the Temperature of the Concrete Cracks in Foundation Mass

In the construction process, the concrete has been get fully utilized, there have been a variety of concrete strength grade configuration requirements and the corresponding raw materials. In the pouring process large volume concrete base, since the temperature stress generation will produce concrete temperature cracks, so the concrete pouring, raw material selection, after pouring temperature control measures have higher requirements. Based on a practical project, the construction of the control temperature stress did some exploratory research.