python pingouin cronbach alpha return value

Question

from pingouin import cronbach_alpha
import pandas as pd
ca_test = pd.DataFrame({'Score1': \[3,4,2,1,3\], 'Score2': \[5,5,2,2,1\], 'Score3': \[5,2,1,3,4\]})

alpha_all = cronbach_alpha(data=ca_test)

print(alpha_all,alpha)
# it prints  (0.5309734513274338, array([-1.37 , 0.948]))

what is the meaning of the second element in this library's return value (using cronbach_alpha object from library to calculate the cronbach alpha )

this one (0.5309734513274338, array([-1.37 , 0.948]))

Answer 1

According to the documentation, that is the confidence interval (CI).

By default, it is the 95% CI.