A scientific claim is a statement that describes or explains a phenomenon of the world. These statements can be proven as valid or invalid only through scientific experiments, which involve testing in controlled conditions the phenomenon. This is the only way because the scientific method should be followed. For example, if the claim is that humidity affects the growth rate of cacti. The researcher will need to use multiple cacti and use different percentages of humidity to prove if humidity increases or decreases the growth rate. Also, in this case, other factors such as nutrients in the soil, exposition to sunlight, etc. should be controlled to guarantee these factors are equal for all plants. According to this, the one that serves as evidence for the scientific claim is controlled experiments.
