Markov Chain

I am casting doubt about using HMM for test_log. Since we have no probabilistic observations in TEST-LOG. I think that for TEST-LOG we can use MARKOV CHAIN instead of HMM. ( in my opinion, the targets are not observed, but they have been logged, e.g: "NavWeb facebook" is not probabilistic observation, and only the transition among targets are probabilistic). I want to compare their results for TEST-LOG. We can use HMM for MONITORING-LOG.