  Reproducibility and reusability of the results of data-based modeling studies
are essential. Yet, there has been -- so far -- no broadly supported format for
the specification of parameter estimation problems in systems biology. Here, we
introduce PEtab, a format which facilitates the specification of parameter
estimation problems using Systems Biology Markup Language (SBML) models and a
set of tab-separated value files describing the observation model and
experimental data as well as parameters to be estimated. We already implemented
PEtab support into eight well-established model simulation and parameter
estimation toolboxes with hundreds of users in total. We provide a Python
library for validation and modification of a PEtab problem and currently 20
example parameter estimation problems based on recent studies. Specifications
of PEtab, the PEtab Python library, as well as links to examples, and all
supporting software tools are available at https://github.com/PEtab-dev/PEtab,
a snapshot is available at https://doi.org/10.5281/zenodo.3732958. All original
content is available under permissive licenses.
