When refering to a claim of value, we are toalking about a type of persuasive rethoric which arguments try to show has, either aesthetical or moral value. In this type of arguments a comparison and evaluation is usually done, they try to stablish the things that should and shouldn't be valued. As values are most of times subjective, these types or arguments often appeal to phatos or emotions. The level of justification required often is beyond fact, this means it can't be proved or campared to reality as they are personal points of views.
The structure "x" is better than "y" is the most common in this arguments as well as "x is as good as y".
Imagine I state: Soccer is better than football. My arguments must appeal to emotions because there is not an objective way to prove it.
