Panda folded into core ranking

What changed

Google confirmed that the Panda quality classifier was now one of the core ranking signals rather than a periodically applied filter. In practice this meant quality assessments updated continuously and Google stopped announcing Panda refreshes. Google noted that Panda was still a signal among hundreds and was not applied in real time in the way Penguin later would be.

Timing

Rollout began 11 January 2016. No completion date was announced. Rankings typically remain unstable for the whole rollout window, so measurements taken inside it are not a reliable read on the outcome.

What it affected