Illustration of estimation method. Raster represents person IDs (total 50 persons, N=50) vs time (60 time-points). Black dots illustrates presence in the register. Here a fixed registration probability of 0.025 was used (i.e. π=0.025). Time is divided into three epochs (i.e. M=3) of equal duration (indicated by the shading). In each epoch the number of previously unregistered persons are counted: first epoch n
1=19, second n
2=10, and third n
3=8. These observed counts are used to estimate the total number of persons in the population. Estimation is done by maximizing the likelihood of N and p given the data. For the example the data in the figure the estimate of N equals 49.