I am in total agreement with 90 percent of his premise. Collecting and analyzing quantitative data can indeed inform your design decisions, and smart use of metrics can fix critical issues or simply improve the user experience. However, this doesn’t preclude a serious problem with data, or more specifically, with data users. Spool makes this clear: When you don’t understand what data can and can’t tell you and your work is being dictated by decisions based on that lack of understanding—well, your work and product might end up being rubbish. (Who hasn’t heard a manager fixate on some arbitrary metric, such as, “Jane, increase time on page” or “Get the bounce rate down, whatever it takes”?) Designing to blindly satisfy a number almost always leads to a poorer experience, a poorer product, and ultimately the company getting poorer.

https://alistapart.com/article/why-we-should-all-be-data-literate/