application or intradermal injection of a substance to the skin to test the body's reaction to it. Such a test detects an animal's sensitivity to such allergens as dust and pollen, or to preparations of microorganisms believed to be the cause of a disorder.
A direct relationship graph is a graph where one variable either increases or decreases along with the other. The general equation for a direct relationship graph is y = mx + b, where y denotes the...
A relationship, or correlation, in research broadly refers to any relationship between two or more variables. A causal relationship is a relationship between variables that occurs when changes in one variable are systematically related to changes in another variable.