One aspect of user experience in a software application or website is the quality of the content presented to the user. It probably comes as no surprise that if the quality of the content is low/poor, then the user will have a difficult time getting a good user experience from trying to achieve his/her goals. The content is generally a mixture of the visual and text that the user processes, so I imagine that there would be a combination of metrics used to assess the visual quality (like aesthetics, contrast) and text quality (like readability, legibility). I would like to know if there are any standard metrics used to measure the relative degree of quality of content that takes into account of various elements that comprise of information quality, and how this relates to the overall user experience.
First of all, content quality and content representation (UI) quality are separate things. You cannot create a beautiful design with messy data.
For testing the interaction design, you can use heuristics evaluation to gauge the various aspects. http://www.nngroup.com/articles/ten-usability-heuristics/
For content, I am unaware of a guide in UX domain for content. But ideally in websites and applications, it is the content writers job to make sure the content is consistent and will interact with the UX designers to make sure the interactions tell the same story.
Edit 1: If you are looking for something in the domain of closely knit content and visuals, the closest thing that comes to mind is Tufte's work. http://www.edwardtufte.com/tufte/books_visex It leans more towards visuals and information visualization which is something what you are talking about.
Also, in context of an organization. I have seen quite a few digital companies which have a group of UX Designers, Visual Designers, Content writers and developers for each project. The UX designer takes care of the theme of the product, the rough layout and interactions, the visual designer takes those concepts and gives it a polished visual layer. The content writer provides the crisp content and the developer ties it all together. They all work together as a team, more of a agile method than a waterfall model.
Never heard about such standard metrics other than readability.
A non-standard metric to judge, how understandable a text (probably) is, can be defined as
With this, 1 means that only plain words are used, and 0 means that no plain word is used (maybe a different language).
Questions that we can ask users to get a feel for information quality (qualitative measures):
The underlying rationale for asking these types of questions are to find out which combinations of the information quality measures are of most value to the users. I believe these are four semi-quantifiable measures of content quality:
I have found also the Search Quality Rating Guidelines, which may be of interest to the people who are still following this question. I guess they are talking more about search query results, but I think it is a subset of the content quality in terms of the usefulness of the information presented.