That the earth is round is a fundamental example of an evidence-based conclusion. The fact that the earth is round was proved long ago, way before modern science, back in ancient Greece. Eratosthenes, a Greek scientist who lived around 200 BCE, figured out that the earth was round because of the shadow it cast on the moon during an eclipse. Now that we can view the earth from space, we can see it is most undoubtedly round. For a writing assignment, think about other hypotheses for the earth's size and shape. Now scientists know that the diameter of the earth is 12,742km, according to a 2009 article in "Universe Today" by Fraser Cain. Scientists also know the earth's shape is an oblate spheroid --- a sphere with a bulge around the equator, not an exact round ball. Ask students to write an narrative essay with a false reason to conclude that their evidence, whatever it may be, is correct. For example, a student may right that she feels the earth is actually only appears round in space because of an optical illusion and give the reasons why.
Ask students to write an observation essay that proves an original evidence-based conclusion. For example, a student that wants to use an evidence-based approach to social policy can look study the effectiveness of certain school programs. She might examine the educational value of teaching sexual education in middle school. Talking with students about their feelings about the program is the first step. Interviewing teachers may be her second. Then, the researcher can study the numbers of students who do not heed the advice to derive reasons for practicing safe sex and how to avoid date rape situations. If the program is, in fact, effective, the student can write an evidence-based conclusion report on why public and private schools should fund sexual education courses. If the programs do not produce positive results, the researcher can suggest in her report that schools cut expenses for these inefficient programs.
Have students create a graphic organizer chart and fill the organizer with lists --- or a web --- of five or six types of bubble gum. They should chew each type of bubble gum a certain number of times before trying to blow a bubble. Then, they ask friends, other students or family to help them with the project. They write the gum and the number, or size, of the bubble in the opposite column in the graphic organizer. They should conclude by deducing through evidence which gum brand produces the most, or the biggest, bubbles. They finish the activity by filling the graphic organizer with all the data and writing a short paper that explains how the experiment worked and how they reached their conclusion.
Ask students to research an already-proven evidence-based conclusion. Nutrition is an ideal research topic, as now scientists and nutritionists know through evidence what minerals and vitamins are essential to keep the human body healthy. Ask students to look at how the researcher came to the conclusion that a certain nutrient is vital for a human. For example, researchers suggest that without niacin, or vitamin B3, the body cannot release energy from carbohydrates, form fat or process alcohol. Following the methodology of their research, ask students to write research papers about one food, vitamin or nutrient proven vital to the human body and to describe their process in coming to that conclusion.