1. Using DDI in Harmonizing Survey Data
Markus Tuominen & Juha Ranta
Case of Finnish Social Science Data Archives Suomi-monitori project
EDDI16 December 6, 2016
Cologne, Germany
License: CC BY 4.0

2. Tietoarkisto | www.fsd.uta.fi

3. Tietomilli-mielipidepuntari
Final product of Suomi-monitori project (2016 ongoing)
Opening archived datasets for public use
Easy to use interface to analyze longitudinal data online
Interactive visualizations with D3 JavaScript library
Tietoarkisto |

4. Access to FSD data online
835 questions
1590 variables
20 datasets
from mainly
two series
Tietoarkisto |

5. Tool to analyze data online
Tietoarkisto |

6. Compare your values
Tietoarkisto |

7. Data in FSD
Datasets in FSD are carefully documented using DDI Codebook
FSD archives DDI descriptions in XML-format
In our project we used existing DDI descriptions to produce harmonized data
Tietoarkisto |

8. Trends and Harmonization
Data series in FSD are well documented but sadly not longitudinally in variable level
We compared every question in the newest wave to other questions in the same series with in-house software in order to find longitudinal instances of a variable
Tietoarkisto |

9. Trends and Harmonization
After assuming an instance of a question the program prompts user to verify
Tietoarkisto |

10. Trends and Harmoni-zation
Produces SPSS syntax based on user input
Tietoarkisto |

11. Used fields in DDI-document
<var>
<qstn>
<qstnLit>question text</qstnLit>
<catgry>
<catValu>answer as value</catValu>
<labl level="category">answer as text</labl>
<catStat>frequency of the answer</catStat>
Tietoarkisto |

12. Challenges faced
Same question formatted differently between study waves
qstnLit –field sometimes contained instructions for answering the question which produced difficulties in comparing short questions
No keywords for variables
Tietoarkisto |

13. Conclusions
Differently formatted questions still remains an unresolved issue
Tools that use DDI Codebook can greatly help in harmonizing longitudinal survey data
<qstnLit> should contain only the question
Visualizing data is fun
Tietoarkisto |