  Context: Detailed oscillation spectra comprising individual frequencies for
numerous solar-type stars and red giants are or will become available. These
data can lead to a precise characterisation of stars.
  Aims: Our goal is to test and compare different methods for obtaining stellar
properties from oscillation frequencies and spectroscopic constraints, in order
to evaluate their accuracy and the reliability of the error bars.
  Methods: In the context of the SpaceInn network, we carried out a
hare-and-hounds exercise in which one group produced "observed" oscillation
spectra for 10 artificial solar-type stars, and various groups characterised
these stars using either forward modelling or acoustic glitch signatures.
  Results: Results based on the forward modelling approach were accurate to 1.5
% (radius), 3.9 % (mass), 23 % (age), 1.5 % (surface gravity), and 1.8 % (mean
density). For the two 1 Msun stellar targets, the accuracy on the age is better
than 10 % thereby satisfying PLATO 2.0 requirements. The average accuracies for
the acoustic radii of the base of the convection zone, the He II ionisation,
and the Gamma_1 peak were 17 %, 2.4 %, and 1.9 %, respectively. Glitch fitting
analysis seemed to be affected by aliasing problems for some of the targets.
  Conclusions: Forward modelling is the most accurate approach, but needs to be
complemented by model-independent results from, e.g., glitch analysis.
Furthermore, global optimisation algorithms provide more robust error bars.
