I've been interpreting for about six years and finally decided to go for my CDI certification. The written knowledge portion is what's stressing me out most. I've been studying roughly 2 hours a day for the last five weeks and feel like I'm barely scratching the surface on the ethical decision-making scenarios.
My practice scores are hovering around 67–71%, and from what I've read online the passing threshold is around 75%. Is that accurate? I'm not sure if I should push my test date back another month or just grind harder for the next two weeks.
The ASL linguistics section feels solid to me, but the RID Code of Professional Conduct questions keep tripping me up. Some scenarios have two answers that both seem defensible and I keep second-guessing myself. Anyone else find that section disproportionately tricky compared to everything else?
Would really appreciate hearing timelines from people who passed — specifically how long you studied and what your practice scores looked like going in.
Six weeks of focused study got me through it, but I was doing about 2.5 hours a day. My practice scores were around 72–74% before I sat the exam and I ended up passing with an 81%. The ethics scenarios clicked once I stopped looking for the perfect answer and started thinking about what protects the Deaf consumer first.
I pushed my date back twice and it was the right call. Sitting at 68% on practice exams wasn't going to cut it, and the extra three weeks got me to 79% consistently. Don't rush just to say you took it — the retake fee isn't worth it.
The RID ethics questions tripped me up too. What helped was reading actual case studies from RID Views journal rather than just the codebook itself. Seeing how the principles play out in real situations made the test question wording feel less ambiguous.
I had similar scores going in and passed on my first attempt. The ASL linguistics portion is very manageable if you have real field experience — lean into that. Budget at least 40% of your prep time on ethics and you should be fine.
I failed my first attempt and honestly it was the ethical decision-making stuff that sank me, same as you. I'd spent five weeks basically rereading the code of ethics over and over, which felt productive but didn't actually help once I hit the scenario questions. They don't ask you to recite the tenets. They put you in a messy situation and want you to reason through it. That's a totally different skill. Second time around I stopped passive reading and started writing out my own answers to practice scenarios, then comparing them against the reasoning, and it clicked way faster than I expected.
The other thing that got me was underestimating how much they push on the modality and language access side. I bombed a whole chunk of that the first go. What turned it around was drilling the question sets, this one in particular helped me a lot cdi/questions/specialized communication modalities and linguistic diversity. So to actually answer your question, my first five weeks were mostly wasted effort, and the second time I needed about four solid weeks but doing the right kind of practice. It's less about total hours and more about whether you're testing yourself or just rereading. You've already put in the time, you just might need to switch how you're using it.
Honestly five weeks at 2 hours a day isn't behind, so don't panic. The thing that finally clicked for me on the ethics section was when I stopped trying to memorize the "right" answer and started asking why the other three were wrong. A lot of those questions have two answers that look correct, and the test is really checking whether you know the line between what's tempting and what's actually within role. If you can explain why an answer crosses a boundary, you don't have to memorize anything. You just see it.
I spent way too long early on just flagging the correct choice and moving on, and it didn't stick because real scenarios never look like the flashcard. Once I started writing a sentence next to each wrong option about what rule or value it violated, the whole thing got easier and I needed fewer weeks than I expected. Give yourself two or three more weeks doing it that way and I think you'll feel a lot more solid. It's less about hours and more about how you're studying.