In response to an unknown trigger, the immune system may begin producing antibodies that instead of fighting infections, attack the body's own tissues. Treatment for autoimmune diseases generally focuses on reducing immune system activity.
What's taught in school. Some of the items in standardized achievement tests measure the knowledge or skills that students learn in school. In certain subject areas, such as mathematics, children learn in school most of what they know about a subject.
A t-test is a statistical method used to see if two sets of data are significantly different. A z-test is a statistical test to help determine the probability that new data will be near the point for which a score was calculated. Learn about these two statistical calculations, their differences, and their similarities.