Correlational finding on Happiness and subject: Out of school contacts with friends (of pupils)

StudyOECD (2017): study TR 2015
TitlePISA 2015 Results. Students' Well-Being. Volume III.
SourceOECD Publishing, 2017, Paris, France
URLhttp://www.oecd-ilibrary.org/education/pisa-2015-results-volume-iii_9789264273856-en
Public15-16 aged, secundary school students, Turkey, 2017
SampleProbability multi-stage random
Non-Response
Respondents N =5895

Correlate
Author's labelTalking with friends
Page in Source Table.III.8.23,p.394+III.8.24
Our classificationOut of school contacts with friends (of pupils)
Operationalization
Selfreport on 2 questions:
- On the most recent day you attended school, did you 
before going  to school meet friends or talk to friends 
on the phone? 
     1 yes
     0 no
- On the most recent day you attended school, did you 
after leaving school meet friends or talk to friends on 
the phone?
     1 yes
     0 no

Observed Relation with Happiness
Happiness
Measure
StatisticsElaboration/Remarks
C-BW-c-sq-l-11-eDM=+ p < .05
Talk with friends before school     
Yes               M = 6,19
No                M = 5,96
- difference         +0,23
C-BW-c-sq-l-11-eDM=+ ns
Talk with friends after school:
Yes               M=  6,16 
No                M=  5,98
- difference         +0,18
C-BW-c-sq-l-11-eDM=+
Talk with friends before or after school:
               All        Boys       Girls
Yes       M=  6,16        6,47       5,84
No        M=  5,91        6,08       5,80
Difference   +0,25(.05)  +0,39(.05)  +0,04(ns)


Appendix 1: Happiness measures used
CodeFull Text
C-BW-c-sq-l-11-eSelfreport on single question:

Here is a picture of a ladder. The top of the ladder '10' represents the best possible life for you and the bottom '0' is the worst possible life for you. In general , where on the ladder do you feel you stand at the moment? Tick the box next to the number that best describes where you stand
10 best possible
9
8
7
6
5
4
3
2
1
0 worst possible life


Appendix 2: Statistics used
SymbolExplanation
DMDIFFERENCE of MEANS
Type: descriptive statistic only.
Measurement level: Correlate: dichotomous, Happiness: metric
Range: depending on the happiness rating scale of the author; range symmetric about zero.

Meaning: the difference of the mean happiness, as measured on the author's rating scale, between the two correlate levels.
Source:
Ruut Veenhoven, World Database of Happiness, Collection of Correlational Findings, Erasmus University Rotterdam.
https://worlddatabaseofhappiness.eur.nl