The most common and obvious fossils are the preserved skeletal remains of animals. Other fossils, which are also evidence of past organisms, include leaf impressions, tracks and trails, burrows, droppings, and root casts.
Lesson Summary. Non-experimental research does not mean nonscientific. Non-experimental research means there is a predictor variable or group of subjects that cannot be manipulated by the experimenter. Typically, this means that other routes must be used to draw conclusions, such as correlation, survey or case study.
Non-Experimental Methods (Descriptive Method) -do not involve as much manipulation, assignment, or control as a true experiment. -hypothesis testing is more flexible. -Data gathered can be used to formulate theories or hypotheses that can be more rigorously tested. Types of Descriptive Studies.