Final answer:
It is true that researchers must consider and control for variables that can affect the relationship between dependent and independent variables to validate their findings.
Step-by-step explanation:
The statement is true; we need to be careful to include variables in our research which might affect the relationship between the dependent variable and the independent variable. In any experiment or study, the independent variable is manipulated to observe the effect on the dependent variable. However, there may be additional variables that could influence this relationship, known as lurking or confounding variables. These must be accounted for or controlled in order to validate the cause-and-effect relationship between the two main variables.
Researchers typically employ techniques like random assignment to control these external variables, ensuring that the only significant difference between experimental groups is the treatment or condition of interest. By isolating the independent variable, we can more accurately determine its direct impact on the dependent variable and maintain the integrity of the experiment.