1. A Good Scientific Question Can Be Tested

Scientific reasoning begins with a question that can be answered with evidence. "Do bean plants grow taller with more light?" is testable. "Are bean plants beautiful?" is not, because it depends on opinion.

A hypothesis is a testable prediction. Many hypotheses use an if-then form: if the amount of light increases, then bean plant height will increase. The words are not magic; the key is that the prediction can be checked with data and could turn out wrong.

Science also separates observations from explanations. "The plant is 18 cm tall" is an observation. "The extra light caused faster growth" is an explanation that needs a fair test. GED® questions often reward this careful separation.

A claim becomes stronger when it is supported by evidence from a well-designed investigation, not just by a guess, opinion, or one unusual example.