How can I quantitatively analyze data collected through 5-point Likert scale which ranges from Always (5), often (4), sometimes (3), rarely (2), to never (1)?
A Likert scale is a set of statements with answer choices range from Strongly Agree to Strongly Disagree so the survey maker can get a holistic view of people’s opinions. All Likert scales also include a mid-point e.g neither agree nor disagree, for those who are neutral on the subject matter.
You should always use rank-based statistical metods for all types of ordered categorical data. (Svensson E. Guidelines to statistical evaluation of data from rating scales and questionnaires. J of Rehabilitation Medicine 2001;33(1):47-48.
I am an expert in statistical methods for ordered categorical data. There are appropriate methods for both cross-sectional and paired data. I have developed methods for paired data - and there are calculation programme as well - look or ask for references!
The Somatic Symptoms Scale (SSS-8) has also a similar response - severity based rating. The analysis process goes through adding all responses and finding a total of the severity of the problem.
Please see this article to understand more:
The 5 severity categories derived from our data were based on the empirical distribution of the SSS-8 sum score. The high and very high symptom burden categories lay in the upper 5% of the severity distribution (ie, ≥95th percentile), which is common in clinical practice. By determining 5 severity categories (no to minimal, low, medium, high, and very high), we follow the taxonomy of frequently used self-report measures, for example, the PHQ-9 depression scale.