Editing Likert scale (section)

{{Short description|Psychometric measurement scale}}
{{sociology}}
A '''Likert scale''' ({{IPAc-en |ˈ|l|ɪ|k|ər|t}} {{respell|LIK|ərt}},<ref>{{cite web |last=Wuensch |first=Karl L. |date=October 4, 2005 |title=What is a Likert Scale? and How Do You Pronounce 'Likert?' |url=https://core.ecu.edu/wuenschk/stathelp/likert.htm |access-date=December 16, 2023 |publisher=East Carolina University}}</ref>{{refn|group=note|Commonly mispronounced as {{IPAc-en|ˈ|l|aɪ|k|ər|t}} {{respell|LY|kərt}} }}) is a [[psychometrics|psychometric]] scale named after its inventor, American social psychologist [[Rensis Likert]],<ref>
{{Cite journal
  | last = Likert
  | first = Rensis
  | author-link = Rensis Likert
  | title = A Technique for the Measurement of Attitudes
  | journal = Archives of Psychology
  | volume = 140
  | pages = 1–55
  | year = 1932 }}</ref> which is commonly used in research [[questionnaire]]s.  It is the most widely used approach to scaling responses in survey research, such that the term (or more fully the '''Likert-type scale''') is often used interchangeably with ''[[rating scale]]'', although there are other types of rating scales.

Likert distinguished between a scale proper, which emerges from collective responses to a set of items (usually eight or more), and the format in which responses are scored along a range. Technically speaking, a Likert scale refers only to the former.<ref>{{Cite book|last1=Spector|first1=Paul E|title=Summated Rating Scale Construction|date=1992|publisher=Sage}}</ref><ref name="IndivLikert ">{{cite journal|last1=Derrick|first1=B|last2=White|first2=P| title=Comparing Two Samples from an Individual Likert Question |journal=International Journal of Mathematics and Statistics |date=2017|volume=18|issue=3|pages=1–13}}</ref> The difference between these two concepts has to do with the distinction Likert made between the underlying phenomenon being investigated and the means of capturing variation that points to the underlying phenomenon.<ref name="Carifio">{{cite journal | last1 = Carifio | first1 = James | last2 = Perla | first2 = Rocco  |date=2007 | title = Ten Common Misunderstandings, Misconceptions, Persistent Myths and Urban Legends about Likert Scales and Likert Response Formats and their Antidotes | journal = Journal of Social Sciences | volume = 3 | issue = 3| pages = 106–116 | doi=10.3844/jssp.2007.106.116| doi-access =  }}</ref>

When responding to a Likert item, respondents specify their level of agreement or disagreement on a symmetric agree-disagree scale for a series of statements. Thus, the range captures the intensity of their feelings for a given item.<ref>{{cite book|last1=Burns|first1=Alvin|title=Basic Marketing Research|year=2008|publisher=Pearson Education|location=New Jersey|isbn=978-0-13-205958-9|pages=[https://archive.org/details/basicmarketingre0000burn/page/245 245]|edition=Second|last2=Burns |first2=Ronald|url-access=registration|url=https://archive.org/details/basicmarketingre0000burn/page/245}}</ref>

A scale can be created as the simple sum or average of questionnaire responses over the set of individual items (questions). In so doing, Likert scaling assumes distances between each choice (answer option) are equal. Many researchers employ a set of such items that are highly correlated (that show high [[internal consistency]]) but also that together will capture the full domain under study (which requires less-than perfect correlations). Others hold to a standard by which "All items are assumed to be replications of each other or in other words items are considered to be parallel instruments".<ref name="vanAlphen1994">{{cite journal | last1 = van Alphen | first1 = A. | last2 = Halfens | first2 = R. | last3 = Hasman | first3 = A. | last4 = Imbos | first4 = T. | year = 1994 | title = Likert or Rasch? Nothing is more applicable than good theory | journal = Journal of Advanced Nursing | volume = 20 | issue = 1| pages = 196–201 | doi=10.1046/j.1365-2648.1994.20010196.x| pmid = 7930122 }}</ref>{{rp|197}} By contrast, [[Item response theory|modern test theory]] treats the difficulty of each item (the [[Item response theory#The item response function|ICCs]]) as information to be incorporated in scaling items.<ref>{{cite journal | last1 = Rusch | first1 = Thomas | last2 = Lowry | first2 = Paul B. | last3 = Mair | first3 = Patrick | last4 = Treiblmaier | first4 = Horst  | year = 2017 | title = Breaking free from the limitations of classical test theory: Developing and measuring information systems scales using item response theory | journal = Information & Management | volume = 54 | issue = 2| pages = 189–203 | doi = 10.1016/j.im.2016.06.005| url = http://epub.wu.ac.at/5356/1/ruschetal2016.pdf }}</ref>