Scientists use the scientific process to which mechanisms underlie observations; they do not if a particular finding is correct or not. a broad statement called a can be used to solidify reasoning before setting up an experiment, and then the scientific process is followed to test one's idea. to illustrate, consider this scenario: suppose you are a researcher investigating the impact of eating eggs on cholesterol levels. your states "consuming an egg everyday increases blood cholesterol". you use a carefully designed experiment to determine if your statement is or not. in this experiment, number of eggs is the , while cholesterol level in the blood is the . you recruit 100 subjects and divide them into two groups: the corresponds to subjects who will eat an egg everyday, and the comprises individuals who will not consume eggs. in order to avoid confounding results, both groups need to have like same gender, similar age, consistent baseline cholesterol measurements, equivalent food consumption, identical exercise routine, etc. in a well-designed experiment, there should only be one variable, but many variables. after a six-month trial, your data show both groups have similar blood cholesterol measurements. your conclusions include that eating one egg everyday for one year does not raise blood cholesterol; your hypothesis was .