There are factors that will help you better understand the engaging quality of your content.
Authorship - With authorship you can establish trust that you or your website are a trusted authority in your niche.
Social Media - Are people posting and tweeting about your content to share it with others? If it is quality, people will talk about it.
Links - If other websites and pages are naturally linking to your content, then that is a good sign that it is considered to be of value.
Bounce Rate - If people are landing on your content and immediately leaving, then that is a good sign that your content is of little use to those visitors or of low quality.