Editing Cronbach's alpha (section)

===Removing items using "alpha if item deleted" always increases reliability===
Removing an item using "alpha if item deleted"{{Clarify|reason=What is "alpha if item deleted"?|date=August 2022}} may result in 'alpha inflation,' where sample-level reliability is reported to be higher than population-level reliability.<ref name=KL>{{cite journal|last1=Kopalle|first1=P. K.|last2=Lehmann|first2=D. R.|title=Alpha inflation? The impact of eliminating scale items on Cronbach's alpha|journal=Organizational Behavior and Human Decision Processes|volume=70|issue=3|pages=189–197|date=1997|doi=10.1006/obhd.1997.2702|doi-access=free}}</ref> It may also reduce population-level reliability.<ref name=r2007>{{cite journal|first=T.|last=Raykov|title=Reliability if deleted, not 'alpha if deleted': Evaluation of scale reliability following component deletion|journal=The British Journal of Mathematical and Statistical Psychology|volume=60|issue=2|pages=201–216|date=2007|doi=10.1348/000711006X115954|pmid=17971267}}</ref> The elimination of less-reliable items should be based not only on a statistical basis but also on a theoretical and logical basis. It is also recommended that the whole sample be divided into two and cross-validated.<ref name=KL/>