Which verb pertains to estimating or measuring the quality of something?

The verb that pertains to estimating or measuring the quality of something is "assess." When you assess, you evaluate or determine the significance, importance, or value of a certain aspect. This process involves careful consideration and judgment based on specific criteria or standards. For example, in an academic context, when students assess a piece of writing, they may look at its clarity, coherence, and argumentation, thereby measuring its overall quality.

In contrast, other verbs do not align with the concept of measuring quality. For instance, to classify involves categorizing items based on shared characteristics, which does not inherently involve evaluating their quality. Arguing focuses on presenting reasons for or against a particular point of view, rather than measuring quality. Clarifying is about making something clearer or easier to understand, which also does not directly relate to the assessment of quality. Thus, "assess" is the correct choice as it directly involves the evaluation of quality.