A co-worker has asked me to help setup a spreadsheet that is used in the analysis of customer care emails. In particular, we are looking at three categories - the assignment of meta-data, content and communication skills.
A typical example question may be:
"How well is the email tailored towards the customers questions?" "How well did the employee answer the customers questions?"
I'm not a statistician but have conducted a few surveys in the past. After seeing the initial survey, which was basically an ad-hoc collection of questions combined with varying scaling mechanisms for each question. I figured the first step would be to iterate the goals and work back from there; otherwise I'd be basically devising my own methods from scratch, which feels a little flakey. All this led me to re-design the survey using the Likert scale due to it's simplicity in implementation and analysis.
However, without a deep statistical background I'm finding it hard to validate why it is better to use a proven methodology than a collection of different scales and measurements aggregated into a single number.
How can I convince them of the benefits if using a 'methodology'/scale such as Likert rather than various choice of measurements?