You are personally known to one of the Program Chairs or Conference Chairs as an expert in your domain who had good judgement about the type and quality of papers we are looking to publish at WSDM. You have a strong publication track record in your domain. You are known to be reliable and responsive.
You are personally recommended by an SPC or a Program/Conference Chair. You have been a PC member at a leading international related conference in recent years and have published at least one paper at WSDM, WWW, KDD, SIGIR, CIKM or related conferences. We will publish the SPC list on our website soon. Consider approaching relevant SPC members in person if you are interested in being nominated as a PC member.