Final answer:
Lurking variables cannot be completely eliminated from an experiment. Random assignment, control groups, placebos, and blinding can help minimize the influence of lurking variables. However, there are certain variables that cannot be eliminated due to practical or ethical reasons.
Step-by-step explanation:
In experiments, one can never truly eliminate lurking variables from the study. Lurking variables are additional variables that can cloud a study and affect the outcome. To prove causation between the explanatory variable and the response variable, researchers must design the experiment in a way that isolates the explanatory variable and minimizes the influence of lurking variables.
This is accomplished through random assignment of experimental units to treatment groups, which helps ensure that the only difference between the groups is the planned treatments. Researchers may also use a control group that receives a placebo treatment, which looks like the active treatment but does not influence the response variable. Blinding, where neither the researchers nor the subjects know which group is the control or experimental group, can also be used to prevent bias.
However, it is important to note that there are certain variables that cannot be eliminated due to practical or ethical reasons. For example, researchers cannot ethically expose human subjects to harmful conditions or test ideas about our ancestors directly. In such cases, researchers rely on observational studies and indirect evidence to gather information.