Answer:
Is the advice supported by empirical evidence?
Explanation:
The best question would be
Is the advice supported by empirical evidence?
In other words, this is asking whether or not there have been actual scientific experiments conducted that resulted in verifiable and documented data regarding the subject. Also that the advice in this website follows the data from the experiments. This would indicate that the advice is based on actual scientific studies that can be reproduced and provide both physical and educative information. Price of the product and popularity of the author do not provide any actual information as to the value of the given advice.
