{"id":1920,"date":"2019-05-18T12:00:00","date_gmt":"2019-05-18T10:00:00","guid":{"rendered":"https:\/\/kindsonthegenius.com\/blog\/machine-learning-questions-and-answers-question-1-to-10\/"},"modified":"2026-07-05T03:23:24","modified_gmt":"2026-07-05T01:23:24","slug":"machine-learning-questions-and-answers-question-1-to-10","status":"publish","type":"post","link":"https:\/\/kindsonthegenius.com\/blog\/machine-learning-questions-and-answers-question-1-to-10\/","title":{"rendered":"Machine Learning Questions and Answers \u2013 (Question 1 to 10)"},"content":{"rendered":"<p>I&#8217;m happy to the making this lesson. I would give you brief answers to several Machine Learning questions. But if you would like to go in-depth, then you can watch the video explanation of the answers.<br \/>\nYou can find Question 1 to 20 below<\/p>\n<p><a href=\"https:\/\/kindsonthegenius.com\/tempsite\/machine-learning-questions-and-answers-question-1-to-10\/\">Questions 1 to 10<\/a>.<\/p>\n<p><a href=\"https:\/\/kindsonthegenius.com\/tempsite\/machine-learning-questions-and-answers-questions-11-to-20\/\">Question 11 to 20<\/a>.<br \/>\nSo let&#8217;s get started!<\/p>\n<p>&nbsp;<\/p>\n<h5><strong>1. What is Maximum Likelihood Estimation(MLE)?<\/strong><\/h5>\n<p><a href=\"https:\/\/kindsonthegenius.com\/blog\/maximum-likelihood-estimation-mle-in-machine-learning\">Maximum Likelihood Estimation<\/a> is a procedure used to estimate an unknown parameter of a model. MLE\u00a0 is based on the <a href=\"https:\/\/kindsonthegenius.com\/tempsite\/what-is-likelihood-function-in-data-science-and-machine-learning\/\">Likelihood Function<\/a> and it works by making an estimate the maximizes the likelihood function.\u00a0 The likelihood function is simply a function of the unknown parameter, given the observations(or sample values).<\/p>\n<p>Therefore, maximum likelihood estimate is the value of the parameter that maximizes the likelihood of getting the the observed data.<\/p>\n<p>&nbsp;<\/p>\n<h5><strong>2. Explain Decision Theory in Machine Learning?<\/strong><\/h5>\n<p>First, I would like to remind you that the <a href=\"https:\/\/youtu.be\/au7KqiBhY3E\" target=\"_blank\" rel=\"noopener\">three fundamental theories of machine learning<\/a> are<\/p>\n<p>Probability Theory, Information Theory and <a href=\"https:\/\/kindsonthegenius.com\/blog\/basics-of-decision-theory-how-medical-diagnosis-apps-work\">Decision Theory<\/a>.<\/p>\n<p>Now, decision theory\u00a0 in Machine Learning is the strategies and method involved in choosing a particular action among a number of probable actions.<\/p>\n<p>&nbsp;<\/p>\n<h5><strong>3. What is Bayesian Model<\/strong><\/h5>\n<p><strong>Bayesian Model<\/strong> is a probabilistic model (a system of making inference) that is based on<a href=\"https:\/\/kindsonthegenius.com\/tempsite\/machine-learning-101-rules-of-probability-bayes-theorem\/\"> Bayes&#8217; Theorem<\/a>. The Bayesian model attempts to obtain a\u00a0 posterior distribution base on some prior distribution.<\/p>\n<p>For example, if we have the density function for some observations <em>X<sub>i<\/sub><\/em> for i = 1 to n to be <em><strong>f(X<sub>i<\/sub> |\u00a0\u03b8)<\/strong><\/em> for unknown parameter\u00a0\u03b8.<\/p>\n<p>Then the prior distribution is given by p(\u03b8), Bayesian model would try to find the parameter using the posterior <strong><em>p(\u03b8 | X)<\/em><\/strong><\/p>\n<p>Just as a reminder, you can find <a href=\"https:\/\/kindsonthegenius.com\/tempsite\/machine-learning-101-rules-of-probability-bayes-theorem\/\">Bayes&#8217; Theorem<\/a> below:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-715 aligncenter\" src=\"https:\/\/www.kindsonthegenius.com\/wp-content\/uploads\/2020\/09\/Final-Bayes-Theorem-300x77.jpg\" alt=\"Final Bayes Theorem\" width=\"300\" height=\"77\" \/><\/p>\n<p>I recommend you watch the video explanation. You&#8217;ll understand it better.<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/wHzATuNYvJE\" width=\"100%\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><span data-mce-type=\"bookmark\" style=\"display: inline-block; width: 0px; overflow: hidden; line-height: 0;\" class=\"mce_SELRES_start\">\ufeff<\/span><\/iframe><\/p>\n<p>&nbsp;<\/p>\n<h5><strong>4. Differentiate between Sensitivity and Specificity<\/strong><\/h5>\n<p>First, I would like to mention that this two terms are related to classification. They are used to describe the performance of a binary classifier.<\/p>\n<p><strong>Sensitivity<\/strong> is the same as true positive rate(TPR): It provides a measure of actual positives that were classified correctly. Formula for sensitivity is given as:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-865 \" src=\"https:\/\/www.kindsonthegenius.com\/wp-content\/uploads\/2020\/09\/Sensitivity-Formula.jpg\" alt=\"Sensitivity Formula\" width=\"599\" height=\"59\" \/><\/p>\n<p><strong>Specificity<\/strong> is the same as true negative rate(TNR): It measures the actual negatives that were correctly classified against the total number of negatives. Formula for specificity is given below:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-866 aligncenter\" src=\"https:\/\/www.kindsonthegenius.com\/wp-content\/uploads\/2020\/09\/Specificity-formula.jpg\" alt=\"Specificity formula\" width=\"615\" height=\"61\" \/><\/p>\n<p>Illustration of Sensitivity and Specificity: Assuming you build a binary classifier to predict if patients have cancer. The classifier, outputs 1 if it thinks patient have cancer and 0 if otherwise. If <em><strong>100<\/strong> <\/em>patients are examined, and the classifier, predicts <strong><em>25<\/em> <\/strong>patient&#8217;s as having cancer whereas the real number of patients having cancer <em><strong>28<\/strong><\/em>, then the Sensitivity would be<strong><em> 25\/28 = 0.89.\u00a0<\/em><\/strong><\/p>\n<p>You can do the same calculation for Specificity.<\/p>\n<p><iframe loading=\"lazy\" width=\"100%\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/noQniIhSnA0\" frameborder=\"0\" allow=\"accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe><\/p>\n<p>&nbsp;<\/p>\n<h5><strong>5. In terms of Bayesian Model, explain the following terms:<\/strong><\/h5>\n<ul>\n<li>\n<h5><strong>Prior<\/strong><\/h5>\n<\/li>\n<li>\n<h5><strong>Conjugate prior<\/strong><\/h5>\n<\/li>\n<li>\n<h5><strong>Posterior<\/strong><\/h5>\n<\/li>\n<li>\n<h5><strong>Likelihood<\/strong><\/h5>\n<\/li>\n<\/ul>\n<p>All these terms follows from the Bayes&#8217; Theorem. In fact these are all you get when you state Bayes&#8217; Theorem.<\/p>\n<p>So if we are trying to deduce the distribution for a parameter\u00a0<em>\u03b8<\/em>,\u00a0 given some set of observation <em><strong>x<\/strong><\/em>, then we can obtain the posterior distribution using Bayes&#8217; Rule as follows:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-867 aligncenter\" src=\"https:\/\/www.kindsonthegenius.com\/wp-content\/uploads\/2020\/09\/Prior-and-Posterior-Probabilities-300x66.jpg\" alt=\"Prior and Posterior Probabilities\" width=\"300\" height=\"66\" \/><\/p>\n<p>From the formula above, the term<em><strong> p(\u03b8 |x)<\/strong><\/em> is known as the posterior probability while the term <em><strong>p(\u03b8)<\/strong><\/em> is known as the prior probability. Also, the term <strong><em>p(x |\u00a0\u03b8)<\/em><\/strong> is known as the likelihood. Now, if\u00a0 the posterior and the prior are in the same probability distribution family, then they are referred to as conjugate prior and conjugate posterior.<\/p>\n<p>Question 5 Video Explanation<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/h6yS2xR5bps\" width=\"100%\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><span data-mce-type=\"bookmark\" style=\"display: inline-block; width: 0px; overflow: hidden; line-height: 0;\" class=\"mce_SELRES_start\">\ufeff<\/span><\/iframe><\/p>\n<p>&nbsp;<\/p>\n<h5><strong>6. What is Dimensionality Reduction<\/strong><\/h5>\n<p>Dimensionality reduction is a procedure used to a dataset with large number of variables using a few principal variables. These can be done by either feature selection or feature extraction. In feature selection, we try to find a subset of the original features while in feature extraction we transform the original data to obtain a new set of features.<\/p>\n<p>&nbsp;<\/p>\n<h5><strong>7. What is Feature Selection<\/strong><\/h5>\n<p>Feature Selection is a dimensionality reduction technique used to transform a dataset from a high-dimensional space to fewer dimension. In feature extraction, the data is represented in a completely new dimension fewer than the original dimension.<\/p>\n<p>&nbsp;<\/p>\n<h5><strong>8. Briefly Explain Principal Components Analysis (PCA)<\/strong><\/h5>\n<p>PCA is a dimensionality reduction technique that makes use of feature extraction. PCA is a procedure that applies orthogonal transformation to transform a set of data of correlated features into dataset of values of linearly uncorrelated variables known as principal components.<\/p>\n<p>&nbsp;<\/p>\n<h5><strong>9. What is Eigen-value Plot<\/strong><\/h5>\n<p>This is also known as graph of eigen-values.<\/p>\n<p>&nbsp;<\/p>\n<h5><strong>10. What is a Biplot<\/strong><\/h5>\n<p>Biplots are a kind of two-variable scatterplot that allows information on both a data matrix and a sample to be displayed on a graph<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I&#8217;m happy to the making this lesson. I would give you brief answers to several Machine Learning questions. But if you would like to go &hellip; <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"pagelayer_contact_templates":[],"_pagelayer_content":"","footnotes":""},"categories":[16],"tags":[],"class_list":["post-1920","post","type-post","status-publish","format-standard","hentry","category-machine-learning"],"_links":{"self":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts\/1920","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/comments?post=1920"}],"version-history":[{"count":1,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts\/1920\/revisions"}],"predecessor-version":[{"id":2088,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/posts\/1920\/revisions\/2088"}],"wp:attachment":[{"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/media?parent=1920"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/categories?post=1920"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/blog\/wp-json\/wp\/v2\/tags?post=1920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}