C A controlled experiment is an experiment in which only one variable is changed at a time Why is it important to do a controlled experiment in order to determine how a
vanable, such as water, light, or temperature, affects seed germination rates?

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.