Date: 8.june 2025 Meeting with Zahra Dates: 30.6. - Zahra has presentation 5.7. - Zahra visits Iran for 2-3 weeks Asking about accuracy measures: * for fit we have goodness of fit measures: - log likelihood - AIC and BIC * these models used for classification: [1] - pred Y = [ Y : f(x|Y) > 0.5 === decision function(x) > 0 [ !Y : otherwise - in logit models: [2] Speech and Language Processing, Ch 5 decision_function(x) = b + w^T x == logit (x) logit == log odds logit(x) = 1/(1 + exp(-decision_function(x)) - ACC == accuracy score [3] accuracy(y, \hat{y}) = 1/n \sum_{i=0}^{n-1} delta_{\hat{y}_i, y_i} - AUC == area under curve ???? [4,5] From [6]: fpr, tpr, thresholds = ROC = function(y_true, y_score) We are systematically doing pred Y[i] = [ 1 : y_score[i] >= threshold [ 0 : otherwise all i and comparing with y_true[i] all i for all meaningful thresholds == y_score Target scores, can either be probability estimates of the positive class, confidence values, or non-thresholded measure of decisions (as returned by “decision_function” on some classifiers). For decision_function scores, values greater than or equal to zero should indicate the positive class. In our case y_score = prob estimate(for Y=1) as given by the model Ref: - [1] https://realpython.com/logistic-regression-python/ - [2] https://web.stanford.edu/~jurafsky/slp3/5.pdf - https://en.wikipedia.org/wiki/Logistic_regression - [3] https://scikit-learn.org/stable/modules/model_evaluation.html#accuracy-score - [4] https://scikit-learn.org/stable/modules/model_evaluation.html#roc-metrics - [5] https://en.wikipedia.org/wiki/Receiver_operating_characteristic - [6] https://scikit-learn.org/stable/modules/generated/sklearn.metrics.roc_curve.html - https://stats.stackexchange.com/questions/354709/sklearn-metrics-accuracy-score-vs-logisticregression-score - https://scikit-learn.org/stable/modules/generated/sklearn.metrics.roc_curve.html - https://scikit-learn.org/stable/modules/model_evaluation.html#roc-metrics Plan: * Make notes overleaf file (ZA) - notes will the basis for the paper and presentations * Transfer as much text and results to notes (ZA) * Test calc. with bayesian model (MH) * Chat about progress at the picnic Ideal: * Have some preliminary results for bayesian model until Friday