A hypothesis represents what researchers predict will happen in an experiment based on more than a guess. It is a statement that can be tested scientifically. For a hypothesis to be valid, it must be a definite statement that can be checked through an experiment involving independent and dependent variables. Examples of valid hypotheses include "daily apple consumption leads to fewer doctor's visits" and "employees who have flexible working hours will report greater job satisfaction than employees who work fixed hours." The null hypothesis is usually that no significant change will occur in the dependent variable based on changes in the independent variable.