Hi everyone,
I am currently working with paneldata. I use them in the long format and am now trying to calculate Cronbach's alpha for some z standardized items. Not all of them were observed in the same year and there are some missings (which are correctly defined as missings).
I have identified the data as paneldata (tsset) and then used
alpha item1 item2 item3 ..., as is
For some combinations of items the error r2000 no observations occurs. If the problematic item is excluded (alpha item2 item3...., as is), stata gives some result.
Then I checked the alpha for the same dataset but reshaped to the wide format (item12000 item12001 etc.). Now I calculated again alpha (also with the problematic items) but only with the years in which the single items had been observed. (alpha item12000 item22001 item32001...., as is). Now no error occured and the size of alpha was different to what it was in the long format (when checked with the same items).
First I thought that there weren't enough observations/too many missings for some of the combinations of items but in the wide format that wasn't the case.
Do you know how the different sizes and the error can be explained?
Do I have to define the dataset differently or is it not possible to calculate alpha for different years?
Thanks in advance for your help!!
Hanna
I am currently working with paneldata. I use them in the long format and am now trying to calculate Cronbach's alpha for some z standardized items. Not all of them were observed in the same year and there are some missings (which are correctly defined as missings).
I have identified the data as paneldata (tsset) and then used
alpha item1 item2 item3 ..., as is
For some combinations of items the error r2000 no observations occurs. If the problematic item is excluded (alpha item2 item3...., as is), stata gives some result.
Then I checked the alpha for the same dataset but reshaped to the wide format (item12000 item12001 etc.). Now I calculated again alpha (also with the problematic items) but only with the years in which the single items had been observed. (alpha item12000 item22001 item32001...., as is). Now no error occured and the size of alpha was different to what it was in the long format (when checked with the same items).
First I thought that there weren't enough observations/too many missings for some of the combinations of items but in the wide format that wasn't the case.
Do you know how the different sizes and the error can be explained?
Do I have to define the dataset differently or is it not possible to calculate alpha for different years?
Thanks in advance for your help!!
Hanna
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