The Likert scale is a summated rating scale developed by Rensis Likert (1932). The attitudinal scale enables research by a company (or a person) to assess the customers perception/attitude towards a product or service or even a concept.
Figure shows a sample statement with a Likert scale for people registered on a CRM course. The scale runs from one extreme (where the respondent totally agrees with the statement) to another (where the respondent totally disagrees with the statement given) and requires the respondent to answer one statement at a time. Neutral options are generally not used among the options though some experts disagree. Each option on the scale assumes equal importance/weight and may be a limitation in some cases. Likert scales can also be scored by weighting the response options unequally (E.g. a score of 5 for strongly agree and 1 for strongly disagree).