Final answer:
A confidence ruler is used to measure subjective levels of confidence, such as (2) how confident a client feels about accomplishing a goal, similar to how a physical ruler measures length. It helps in tracking progress and motivation.
Step-by-step explanation:
An appropriate use of a confidence ruler is to gauge how confident a client feels about accomplishing the week's goal. This application falls under tools used in the field of psychology and coaching to quantify and track individuals' confidence levels regarding different tasks or goals. By asking the client to rate their confidence on a scale, much like a ruler would measure length, practitioners can gather subjective, yet quantifiable, data that can be used to support the client's progress.
For instance, option 2, 'To gauge how confident a client feels about accomplishing the week's goal', is a direct application of the concept of measuring and tracking progress and motivation using a metaphorical ruler. When used appropriately, this technique can provide a simple yet effective way of visually capturing a client's self-reported confidence, which can then be used to discuss and potentially enhance motivation and commitment to the set goals.