gwhite wrote:So you're going to have to explain how you know an animal was missing while another was present. The one case I've seen that made some sense was trapping on 2 different study areas with the assumption that animals did not move between areas, and some occasions were not trapped on just one of the areas.
The real point is that if you know an animal is missing, then p = 0, which is what a dot does in an encounter history. But if you put in a zero, then how did you know it was present? A 1 in the encounter history is obvious -- the animal was present.
Gary
Sorry for not providing a clear explanation of our project and for not providing sufficient information, which led to confusion.
We are using MARK and the capture-mark-recapture in an unusual way as we are not looking at animals but the pathogenic bacteria in the babies. We are really interested in applying the capture-mark-recapture technique to our research to estimate the probability of failing to detect the presence of bacteria even when it might be there.
We are working on a longitudinal study in which we monitor the presence of bacteria in the babies by collecting samples from the babies at 13 consecutive time points across 2 years. Due to the sampling techniques, it is possible that people failed to collect bacteria while bacteria were present in the babies. We want to apply the capture-mark-recapture technique in our study to estimate the probability of failing to detect the presence of bacteria, especially with the CJS model where we can estimate the recapture rate.
What we currently do is that when we received the samples, we detected the presence of the bacteria. If bacteria are present in the sample, we labeled the sampling occasions as “1”, if not, we label them as “0”. However, some samples were never sent to us, so those missing sampling occasions were labeled as “dots”. The “dots” essentially represent “lost samples” and it is unknown if they were 1 or 0. Each encounter history represents an individual baby.
I would greatly appreciate any feedback or suggestions regarding the most suitable strategy.