“…Each noisy-AND gate uses a slip parameter to capture the the probability of accidentally failing a known item, and a guess parameter to capture the probability of correctly answering an item by chance. In this avenue of work, some use a hierarchical structure among skills, yet focus on either the prerequisite relations among intrinsically di erent skills [6,9,24], or granularity relationships (including competencybased networks) [8,9,32,33,35], where higher level nodes denote more abstract, more general, aggregated skills at which level remediation doesn't directly operate. They are substantially di erent from the integration relationship that we model and the level of remediation that we target here.…”