Ah. You've been bitten by evil Likert scales. Their casual and common misuse is a cause of so much misery (and so, so, so many inappropriate psychometric conclusions). Just because an interpretive method is commonly used does not make it valid! For a brief overview, see: Jamieson, S. (2004). Likert scales: How to (ab) use them. *Medical Education*, 38, 1212-1218. doi:10.1111/j.1365-2929.2004.02012.x