Min and Max of Cronbach's alpha coefficient

[Junior Boumsong]

Dear All,

I have constructed a composite variable (organizing capacity) measured with 6 items and 3 likert scale (1= weak, 2= middle, 3= strong).

Here are the results of descriptive statistics:

Alpha Cronbach: 0.75
Mean: 2.401
SD: 0.472
Min: 1.167
Max: 3

I have constructed another composite variable (recruitment capacity) measured with 8 items and 4 likert scale (1= not used, 2= used rarely, 3=used occasionally, and 4= used frequently)

Here are the results of descriptive statistics:

Alpha Cronbach: 0.66
Mean: 2.541
SD: 0.573
Min: 1
Max: 3.875

My concern is why the Min of the first composite variable is 1.167 and the Max of the second composite variable is 3.875. And I am wondering if my results are logic.

After checking, I have noticed that there is no missing values. But it seems that these values (Min and Max) come from the first column [mean(unstandardized items)] of the tables below after using the tabulate command

Does anyone can help me to understand my results?

[Maarten Buis]

I suspect that you expected the minimum to be 1 and the maximum to be 4, but that would only happen if there is an individual in your dataset who has all 1s on all 6 items or all 4s on all 8 items. Apparently, you did not find such an individual. That is not a problem, it is just an empirical finding.

[Junior Boumsong]

Thank you so much!