The reason a scale is not a good measuring tool is because your weight might not be going down, but you can still be losing fat. (coachcalorie.com)
The issue is, does this affect an author's ability to sell the next project because there are people out there still selling this thing as an accurate measuring tool? (adistantsoil.com)
I think you are using observation to mean human senses and I use observation to mean any of our five senses or measuring tools created as an extension of those senses. (religion.blogs.cnn.com)