 It's the last video in this series of short terminology videos that help you to understand disease transmission, disease spread, epidemiology, etc. And that is sensitive versus specific or we will use the terms sensitivity versus specificity. So here's how I remember them real quickly. If you want to like like almost just a little quick device, sensitivity has an N in it. So sensitivity, I think no false negatives specificity has a P in it. So I think no false positives. So what does that actually mean though? Sensitivity would be I know that my patient has this disease. What are the chances that the test that I'm doing is going to show that the patient has it? And that's what I mean by no false positives. If a test is 100% sensitive, then everyone that has the disease will be told they have the disease. So you won't have any false negatives. A false negative is when someone has a disease and a test shows they don't. So a good example of that would be like rheumatoid arthritis. Some of these autoimmune disease tests are not very sensitive. So for example, people could have raging cases of rheumatoid arthritis and maybe only have a 70% chance that some of these antibody tests would actually say that they have the disease. So that's a test that's not very sensitive. So if a test is sensitive, there won't be these false negatives. Specificity would be I know my patient doesn't have a disease. What are the chances that the test is going to say that they have or don't have it? So specificity would mean no false positives. If someone doesn't have a disease, what are the chances that the test comes back and says that they do? So that's what a false positive is. Obviously, when I think of false positives, the first thing I think of would be like mammograms or any time people are doing imaging or full body scans, you can find all sorts of lumps and bumps and nodules in a human being. And you have to assume the worst, but if a test isn't very specific, you can't be sure that it isn't a false positive. That's so like on a mammogram, if you find a lump or a bump, it could be a lipoma, it could be something completely benign, but a false positive readout would tell you that it would be something like breast cancer. So that is sensitivity, which means a test would have no false negatives. Specificity, a test would have no false positives. I hope that helps. Have a wonderful day. Be blessed.