Edward and Elvira developed a 50-item scale that measured the extent to which people were gullible to practical jokes. After collecting data from 1,000 participants, their scale demonstrated poor internal consistency (Cronbach's alpha = 0.40). What (if any) suggestions would have the potential to dramatically increase the overall reliability of their scale? (circle all that apply)
A) Review the item-total correlations for every item in the scale, and delete those items that are poorly correlated with the majority of other items.
B) Add 10 relatively "good" items to the scale.
C) Recruit another 1,000 participants to reduce the effect that random error has on the inter-item covariations.
D) Run a factor analysis for the total scale, and upon noticing that the scale was unintentionally multidimensional, eliminate all items that do not load on Factor 1.

Question

Quizplus · Accepted Answer

A) Reviewing the item-total correlations and deleting poorly correlated items can increase the internal consistency of the scale by removing items that are not measuring the same construct as the others. 
D) Running a factor analysis can reveal if the scale is unintentionally multidimensional, and eliminating items that do not load on the primary factor can increase the reliability of the scale. Adding more items (B) may improve the content validity of the scale, but may not necessarily improve internal consistency. Recruiting more participants (C) can improve precision and generalizability, but may not have a direct impact on internal consistency.

Edward and Elvira Developed a 50-Item Scale That Measured the Extent