This report presents the outcome of the in-forum workshop on area (a) of the work programme on the impact of the implementation of response measures, "Sharing of information and expertise, including reporting and promoting understanding of positive and negative impacts of response measures", which was held on 27 November 2012 at the Qatar National Convention Centre in Doha, Qatar. The workshop provided an opportunity for Parties and relevant organizations to exchange information, experiences, best practices and views in relation to the impact of the implementation of response measures. Such information, experiences and views will serve as input to the relevant discussions of and consideration by the subsidiary bodies, in particular when conducting the review of the work of the forum on the impact of the implementation of response measures at their thirty-ninth sessions, with a view to providing recommendations to the Conference of the Parties at its nineteenth session, as mandated by decision 8/CP.17