Likert-type Ratings

Similarly, a sum or total of item responses will give a broader range of scores than the individual Likert-type ratings. For this reason, many psychologists and statisticians treat scales created in this fashion as interval scales even if they view the individual Likert-type ratings as ordinal scales.

• We call these scales "approximately interval" or "roughly interval" to indicate that they strictly speaking are not interval but are being treated as such in data analysis.
  
  
• Some scientists group together approximately interval, interval and ratio scales into a larger category of "scale" or "score" data.