the data. The main contribution to this additional scatter appears to be reduction noise (i.e., differences in implementation of the analysis).

5.  Estimation of uncertainties in the large spacings, from fits made to prominent peaks in the autocorrelation of the power frequency spectrum, must make proper allowance for the strong correlations that are present in the autocorrelation function.

The next phase of the exercise will involve true blind tests on single timeseries of new stars. We then intend to use the results, together with further tests on the data here, to inform development and refinement by the KASC of the analysis pipeline for extracting the frequency spacings. The results of the asteroFLAG exercises also need to be understood in the context of the Kepler simulations undertaken at Aarhus (see Christensen-Dalsgaard et al. 2007).

We are extremely grateful to the International Space Science Institute (ISSI) for support provided by a workshop programme award. This work was also supported by the European Helio- and Asteroseismology Network (HELAS), a major international collaboration funded by the European Commission’s Sixth Framework Programme. We thank the VIRGO/SOHO team, whose data we used. SOHO is a mission of international cooperation between ESA and NASA.

Aigrain S., Favata 