===== Pattern Recognition ===== - The first question was about the performance evaluation of classifiers. Definition of recognition rate, recall and precision. - The Bayesian classifier and I had to write the decision rule using Bayes formula. What each of the terms meant and how can we calculate them (estiation of parameters). Also I mentioned optimality with respect to the 0/1 loss function, so he asked what are different loss functions that we can use and when it is appropriate to use it. - At if we have too many parameters to estimate? What can we do? (Use naïve bayes or to use feature transform) - Than in connection to the feature transform he asked me to explain PCA. - What is a perceptron and how can we get the decision boundary of it? - How we can use perceptron in case of AdaBoosting. - He then asked me about the Viola Jones algorithm and how boosting is used in it? - What are SVMs? I explained both soft and hard decision case. - If we have any distribution how can we model it using gaussians? What are the different parameters we have to estimate and how are they estimated? He drew a diagram of a distribution with initial means assigned and asked me what will happen after the first step? - The Gaussian mixture model, what happens in the expectation and maximization step and which parameters are estimated in each case. - He then draw down 3 probabilities for the 3 gaussians and asked me how would i perform EM algorith for given measurement points. More or less that was what he asked me. Usually, the next question was connected to the previous one.