Study Ventegodt (1997): study DK 1993
- Public
 - 31-33 aged, born at the university hospital, Denmark, 1993
 - Sample
 - Respondents
 - N = 4626
 - Non Response
 - 36%
 - Assessment
 - 
        Questionnaire: Paper & Pencil Interview (PAPI)                    
Data were taken from the medical files of mothers and their babies 
Correlate
- Authors's Label
 - Visual function shortly after birth
 - Our Classification
 - 
            
 - 
                        
 - Remarks
 - day 1 and day 5 do have a reversed outcome
 - Distribution
 - 
                N day 1 all:4020,    1:87,1%,   2:12%,   2b: 0,1%,   2c:5,4%,   2d:0,1%,   2e:3,0%,   2f:1,5%,   2g:2,0%,   2h:0,2%,   2i:0,6%
N day 5 all:4325, 1:85,4%, 2b:0.2%, 2c:4,5, 2d:0,4, 2e:0,8, 2f:3,7, 2g:1,7, 2h:0,8, 2i:2,5 - Operationalization
 - Visual function shortly after birth as reported in medical file:
1:coordinated or normal
2:one of the following:
2b: retinal bleeding
2c: uncoördinated
2d: congenital anomaly
2e: nystagmus
2f: subconjunctivis bleeding
2g: conjunctivis
2h: seen by eye doctor with pathological findings(omitting 1a and 1b)
2i: seen by the eye doctor with normal findings
Assesed at day 1 and day 5 
Observed Relation with Happiness
1: Mt=7.73 1:7.73
2: Mt=7.85 2:7.66
2b: Mt=10.0 2b:7.50
2c: Mt=7.86 2c:7.73
2d: Mt=6.25 2d:7.98
2e: Mt=7.86 2e:7.58
2f: Mt=7.59 2f:7.54
2g: Mt=7.91 2g:7,68
2h: Mt=7.78 2h:7,91
2i: Mt=7.60 2i:7.90
1: Mt=7.40 1:7.43
2: Mt=7.55 2:7.40
2b: Mt=9.38 2b:7.50
2c: Mt=7.63 2c:7.46
2d: Mt=6.66 2d:8.13
2e: Mt=7.54 2e:7.09
2f: Mt=7.29 2f:7.19
2g: Mt=7.50 2g:7.46
2h: Mt=7.78 2h:7.85
2i: Mt=7.19 2i:7.48
1: Mt=7.03 1:7.03
2: Mt=7.10 2:6.19
2b: Mt=9.38 2b:7.19
2c: Mt=7.08 2c:7.05
2d: Mt=7.09 2d:7.35
2e: Mt=7.14 2e:6.60
2f: Mt=6.96 2f:6.91
2g: Mt=7.03 2g:6.96
2h: Mt=7.78 2h:6.95
2i: Mt=6.46 2i:7.29