Hello,

This is an unusual question as it involves statistical platforms outside of Stata. I'm teaching a statistics class and am producing labs in Stata but permitting students to complete them in SPSS or JASP (my institution doesn't have a campus-wide license). While there are some discrepancies across platforms I can usually figure out what is producing it, but I'm running into an issue where the differences are quite sizeable.

Code:
Stata v15 
swilk ABANDON 
                   Shapiro-Wilk W test for normal data 
    Variable |        Obs       W           V         z       Prob>z 
-------------+------------------------------------------------------ 
     ABANDON |      1,487    0.99971      0.258    -3.406    0.99967 

SPSS v26 
                   Shapiro-Wilk W test for normal data 
    Variable |        Obs       W           V         z       Prob>z 
-------------+------------------------------------------------------         unlabelled statistic is 0.898904
     ABANDON |      1,487      ???         ???     -3.406    0.99967 

JASP v15 
                   Shapiro-Wilk W test for normal data 
    Variable |        Obs       W           V         z       Prob>z 
-------------+------------------------------------------------------         unlabelled statistic is 0.898904
     ABANDON |      1,487      ???         ???     -3.406    0.99967
The z-values produced, which I determined from the listed p-values in their respective programs, were identical. But the test statistics are neither W nor V.

Does anyone have any insight into what SPSS and JASP are reporting in this case - or alternatively, whether Stata is using a unique formula for the normality test?

Cheers,

David.