Final answer:
The correct answer is Option 2: experimental; observational. This is because in an experimental method, the researcher manipulates variables while in an observational method, the researcher merely observes without intervention.
Step-by-step explanation:
The method of collecting data that involves manipulating response variables is referred to as an experimental method, and the method in which conclusions are drawn by comparing data collected from two groups without regulating any factors is known as an observational method. Therefore, the correct answer to the question would be Option 2: experimental; observational.
In an experimental study, the researcher actively intervenes, manipulating the independent variable to observe its effect on the dependent variable. A classic example of this is a clinical trial where one group receives a treatment and the other group receives a placebo. An observational study, on the other hand, involves monitoring without intervention. Researchers gather data on naturally occurring variables without manipulating them, which is appropriate when ethical or practical limitations prevent active manipulation.