How to relate raw scores on five-point Likert to three conceptual categories? My thesis is on employee productivity and I had a questionnaire which consists of a five-point Likert scale (5-strongly agree, 4-agree, 3-agree, 2-disagree, and 1-strongly disagree). On the other hand, I had a conceptual Framework of a 3 point scale (Highly Productive, Productive and Not Productive). 
Is there any standard way to identify whether my respondents are highly productive, productive or not?
 A: Many psychological tests convert numeric raw scores into categories. For example, Wikipedia mentions cut-offs for the Beck Depression Inventory:

  
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*0–9: indicates minimal depression 
  
*10–18: indicates mild depression
  
*19–29: indicates moderate depression 
  
*30–63: indicates severe  depression.
  

Or for example the BMI define various cut-offs (e.g., Cole et al, 2007). 
In general, you lose information by collapsing categories or using cut-offs. Psychological reality tends to be more continuous. That said, categories do have heuristic value as decision aides.  
A few options for converting scores to a collapsed set of categories


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*Use the logical definition of the scale points: For example, you might use "strongly agree" as highly productive, "agree" as productive, and the other categories as "not productive". This is a simple approach that uses the scale anchor points to define the meaning of the categories.

*Use expert judgements: You can ask a set of experts to evaluate where they thinlk the cut-offs between categories should be. These can then be synthesised. This approach is often used to define acceptable standards for various tests.

*Use normative information: You could use information about the normative spread of the variable and an assumption about the prevalence of the phenomena to define cut-offs. 

*Use prediction of external criterion: If the thing has objective existence, or if there are things related to it, you could use predictive models of this external criterion to define the categories.


References


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*Cole, T. J., Flegal, K. M., Nicholls, D., & Jackson, A. A. (2007). Body mass index cut offs to define thinness in children and adolescents: international survey. Bmj, 335(7612), 194. FULL TEXT
