Advantages and Disadvantages of the Computer Based IELTS test (CBT). Comments below come from various IELTS candidates. This known as CD IELTS (computer delivered IELTS) or CBT (computer-based test). Is the computer based IELTS test different? No. It is the same test but you put your answers on the computer rather than on to paper. … Continue reading Computer Delivered IELTS: Pros & Cons