In the context of school, particularly when providing feedback on children's work, WWW stands for "What Went Well".
This is according to a teacher quoted in a news article on leicestermercury.co.uk. The article explains that teachers use WWW, alongside EBI ("Even Better If"), to give constructive feedback to students. WWW highlights the positive aspects of a student's work, helping them understand what they are doing correctly. This helps children understand where they are doing well and where they need to improve.
