Editing Cronbach's alpha (section)

===Nunnally's recommendations for the level of reliability===
Nunnally's book<ref name="n1">{{cite book|first=J. C.|last=Nunnally|title=Psychometric theory|publisher=McGraw-Hill|date=1967|isbn=0-07-047465-6|oclc=926852171}}</ref><ref name="n3">{{cite book|last1=Nunnally|first1=J. C.|last2=Bernstein|first2=I. H.|title=Psychometric theory|publisher=McGraw-Hill|edition=3rd|date=1994|isbn=0-07-047849-X|pages=|oclc=28221417}}</ref> is often mentioned as the primary source for determining the appropriate level of dependability coefficients. However, his proposals contradict his aims as he suggests that different criteria should be used depending on the goal or stage of the investigation. Regardless of the type of study, whether it is exploratory research, applied research, or scale development research, a criterion of 0.7 is universally employed.<ref name="LBM">{{cite journal|last1=Lance|first1=C. E.|last2=Butts|first2=M. M.|last3=Michels|first3=L. C.|title=What did they really say?|journal=Organizational Research Methods|volume=9|issue=2|pages=202–220|date=2006|doi=10.1177/1094428105284919|s2cid=144195175}}</ref> He advocated 0.7 as a criterion for the early stages of a study, most studies published in the journal do not fall under that category. Rather than 0.7, Nunnally's applied research criterion of 0.8 is more suited for most empirical studies.<ref name="LBM"/>
{| class="wikitable" style="text-align: right;
|+ Nunnally's recommendations on the level of reliability
|-
! !! 1st edition<ref name=n1/> !! 2nd & 3rd<ref name=n3/> edition
|-
| Early stage of research|| 0.5 or 0.6|| 0.7
|-
| Applied research|| 0.8|| 0.8
|-
| When making important decisions|| 0.95 (minimum 0.9)|| 0.95 (minimum 0.9)
|}

His recommendation level did not imply a cutoff point. If a criterion means a cutoff point, it is important whether or not it is met, but it is unimportant how much it is over or under. He did not mean that it should be strictly 0.8 when referring to the criteria of 0.8. If the reliability has a value near 0.8 (e.g., 0.78), it can be considered that his recommendation has been met.<ref name = c2020>{{cite journal|first=E.|last=Cho|title=A comprehensive review of so-called Cronbach's alpha|journal=Journal of Product Research|volume=38|issue=1|pages=9–20|date=2020|doi=}}</ref>