Statistical Methods for the Qualitative Assessment of Dynamic Models with Time Delay (R Package qualV)

Research output: Contribution to journalResearch articleContributedpeer-review


  • Stefanie Jachner - , TUD Dresden University of Technology (Author)
  • K. Gerald van den Boogaart - , University of Greifswald (Author)
  • Thomas Petzoldt - , Chair of Limnology (Author)


Results of ecological models differ, to some extent, more from measured data than from empirical knowledge. Existing techniques for validation based on quantitative assessments sometimes cause an underestimation of the performance of models due to time shifts, accelerations and delays or systematic differences between measurement and simulation. However, for the application of such models it is often more important to reproduce essential patterns instead of seemingly exact numerical values.

This paper presents techniques to identify patterns and numerical methods to measure the consistency of patterns between observations and model results. An orthogonal set of deviance measures for absolute, relative and ordinal scale was compiled to provide informations about the type of difference. Furthermore, two different approaches accounting for time shifts were presented. The first one transforms the time to take time delays and speed differences into account. The second one describes known qualitative criteria dividing time series into interval units in accordance to their main features. The methods differ in their basic concepts and in the form of the resulting criteria. Both approaches and the deviance measures discussed are implemented in an R package. All methods are demonstrated by means of water quality measurements and simulation data.

The proposed quality criteria allow to recognize systematic differences and time shifts between time series and to conclude about the quantitative and qualitative similarity of patterns.


Original languageEnglish
Pages (from-to)1-30
Number of pages30
JournalJournal of statistical software
Issue number8
Publication statusPublished - Sept 2007

External IDs

WOS 000252430200001
Scopus 37649025181
ORCID /0000-0002-4951-6468/work/142256771


Research priority areas of TU Dresden


  • ecological modeling, qualitative validation criteria, time shift, R, PATTERN