Likert Scale

 Likert developed the principle of measuring attitudes by asking people to respond to a series of statements about a topic, in terms of the extent to which they agree with them, and so tapping into the cognitive and affective components of attitudes. A Likert scale assumes that the strength/intensity of experience is linear, i.e. on a continuum from strongly agree to strongly disagree, and makes the assumption that attitudes can be measured. 

 A scale can be created as the simple sum of questionnaire responses over the full range of the scale. In so doing, following characteristics should be considered. 

 - Symmetry: They contain equal numbers of positive and negative positions whose respective distances apart are bilaterally symmetric about the "neutral" value

- Balance: The distance between each candidate value is the same, allowing for quantitative comparisons such as averaging to be valid across items containing more than two candidate values. The format of a typical five-level Likert item could be

   

   strongly disagree / disagree / neutral / agree / strongly agree

Likert scaling is a bipolar scaling method, measuring either positive or negative response to a statement. Sometimes an even-point scale is used, where the middle option of "neutral" is not available. This is sometimes called a "forced choice" method, since the neutral option is removed. 

 In illustration, the diverging stacked bar charts is highly recommended [Plotting Likert and Other Rating Scales - 2011]. Diverging stacked bar charts make it easier to compare the attitudes of respondents in different demographic categories or who differ on the importance of increasing professional recognition than do any other figures discussed.