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.
To calculate the standardized mean difference between two groups, subtract the mean of one group from the other (M 1 V M 2) and divide the result by the standard deviation (SD) of the population from which the groups were sampled.o calculate the standardized mean difference between two groups, subtract the mean of one group from the other (M 1 V M 2) and divide the result by the standard deviation (SD) of the population from which the groups were sampled.