Similar to Fischbacher and G¨achter (2010) we try to understand and explain the motivation of participants when contributing to a public good. In the Hybrid Public Good experiment each of two interacting contributors chooses an independent contribution level and three adjusted contribution levels when (s)he, as the only adjusting player, learns that the other’s independent contribution is smaller, equal or larger than the own one. We systematically vary the probability that one player can adjust, based on such qualitative information, but maintain that no adaptation at all and adaptation by only one occurs with positive probability. Adaptation is framed in two ways, once by additively changing the own independent contribution and once by stating new contribution levels. Surprisingly, there is a strong framing effect which increases with experience. Reacting to coinciding independent contributions implies impressive conformity in contributing. Reacting to higher, respectively lower independent contributions implies average upward, and, more strongly, downward adaptation.