An online platform for teaching upper secondary school computer science

The teaching of computing in schools is relatively new, with limited research informing what to teach and how in upper secondary contexts. However, computing education has spawned the development of many tools for use in such education settings.Isaac Computer Science is a computer science (CS) learning platform aimed at school students in England aged 16 to 19 years old studying for formal A level CS qualifications. Over 34,000 students and over 2,400 teachers have registered on the platform to date, and over 1 million online questions have been attempted. The platform is pre-populated with CS content and questions. Feedback is tailored to respond to common mistakes. Hints and explanation videos accompany questions. Question sets can be assigned to students by teachers. Question types include Parsons problems, drag and drop, multiple-choice and text-matching answers, including Boolean Algebra responses. Students only see content, questions and notation pertinent to their course of study. Isaac CS has a centrally-organised ongoing provision of support, such as teacher professional development and student events.This tools design paper outlines the development of Isaac CS through a review of design decisions and the effectiveness of its features. The review is informed by literature, platform usage data and teacher and student feedback. The discussion is framed in terms of online learning theories and a knowledge appropriation model. We suggest a new model, a Platform Pedagogy Matrix, which may be of use to other platform developers and researchers.