SPSS to Stata

[Miguel Fonseca]

Dear Statalist,

I'm currently trying to replicate a piece of analysis originally done on SPSS in Stata 17 (Mac OS); specifically, a repeated-measures ANOVA.

The original SPSS code is:

GLM confrontT1 confrontT3 WITH changeconfrontCOVID  
/WSFACTOR=toename_confront_speed 2 Polynomial    
  /METHOD=SSTYPE(3)    
   /EMMEANS=TABLES(toename_confront_speed) WITH(changeconfrontCOVID=-30)COMPARE ADJ(LSD)    
   /EMMEANS=TABLES(toename_confront_speed) WITH(changeconfrontCOVID=0)COMPARE ADJ(LSD)    
   /EMMEANS=TABLES(toename_confront_speed) WITH(changeconfrontCOVID=30)COMPARE ADJ(LSD)  
 /PRINT=DESCRIPTIVE ETASQ    
 /CRITERIA=ALPHA(.05)  
 /WSDESIGN=toename_confront_speed    
 /DESIGN=changeconfrontCOVID.

The variables confrontT1 and confrontT3 are measures of intention to confront individuals who violate a social norm measured at time 1 and 3; changeconfrontCOVID is a control variable about perceptions a Covid-related norm.

The analysis was done on a dataset in wide format. I first reshaped the dataset into long format. The variables "confrontT1" and "confrontT3" are now "confrontT", "real_id" is an individual identifier, and "t" is time. The variable changeconfrontCOVID is a non-integer ranging from -100 to 100. A sample of the long format dataset is below,

* Example generated by -dataex-. For more info, type help dataex
clear
input double confrontT float real_id byte t double changeconfrontCOVID
  5  3 1 -29.5
  4  3 3 -29.5
  6  5 1    18
  6  5 3    18
4.5  7 1     .
  1  7 3     .
  6 19 1  -7.5
  7 19 3  -7.5
1.5 21 1    30
1.5 21 3    30
  5 23 1   -65
3.5 23 3   -65
  1 24 1  22.5
  1 24 3  22.5
  4 32 1    62
end

Based on the Stata documentation, I believe the correct syntax should be:

anova confrontT c.changeconfrontCOVID / i.real_id | c.changeconfrontCOVID t c.changeconfrontCOVID#t, repeat(t)

However, I get the error message

invalid interaction specification;
'|' requires a factor variable on each side

If I remove the factor-variable operators and type real_id | changeconfrontCOVID, I get the following error message

changeconfrontCOVID: factor variables may not contain noninteger values

I was wondering if you could tell me how to work around this issue. I would be grateful for any help.

Best regards,
Miguel Fonseca