If you are or have been a classroom teacher, most likely you will have heard a student ask this question. Instead of being annoyed, understand the student is doing you a favor. They are letting you know your lesson plan is not working for them. They are giving you feedback to be used in formative assessment. They are telling you exactly what they need in order to learn. Listen and answer their question.
This question can also become relevant for teachers when evaluating online resources. Questions arise. Does the online resource actually work? If the resource works, does it satisfy a need? How much time will be involved with effectively using the resource? Does the resource enhance student understanding and retention?
Honestly, at the end of the day, the last question is the one which matters the most.
Resource: Online assessment tools: A sample of each of the following tools has been reviewed: quiz and test builder, peer-to-peer interaction, course tracking, and reflective assessment. Your feedback is welcome as well as suggestions for other tools available in these categories.