We have a lot of data regarding a 5 point ordinal scale with descriptors for each point like 'very little' to 'very much'.  I am worried that this scale will show insufficient variance in a further study I am designing, and would like to extend it in some way which a) captures meaningful information but b) maintains maximum comparability to the previous data.Options under consideration:1 - add blank items in between each of the old items on the horizontal row, rely on individuals to interpolate.2 - invent new labels which somehow fit in between the old.  This may be linguistically challenging.3 - convert to a numeric scale with comparably labeled beginning, mid, and endpoints4- convert to a numeric scale using the old labels at every appropriate point, and blanks otherwise.Adding additional questions to capture the variance is not an option, but I'm interested in any others I haven't thought of, and for and against arguments.  
Extending a 5 point ordinal scale to 9 points while maintaining comparability
measurement;methodology