-nearest neighbors concepts let' talk about few data mining and machine learning techniques that employers expect you to know about we'll start with really simple one called knn for short you're going to be surprised at just how simple good supervised machine learning technique can be let' take lookknn sounds fancy but it' actually one of the simplest techniques out therelet' say you have scatter plot and you can compute the distance between any two points on that scatter plot let' assume that you have bunch of data that you've already classifiedthat you can train the system from if have new data pointall do is look at the knn based on that distance metric and let them all vote on the classification of that new point let' imagine that the following scatter plot is plotting movies the squares represent science fiction moviesand the triangles represent drama movies we'll say that this is plotting ratings versus popularityor anything else you can dream upherewe have some sort of distance that we can compute based on rating and popularity between any two points on the scatter plot let' say new point comes ina new movie that we don' know the genre for what we could do is set to and take the nearest neighbors to this point on the scatter plotthey can all then vote on the classification of the new point/movie you can see if take the three nearest neighbors ( = ) have drama movies and science fiction movie would then let them all voteand we would choose the classification of drama for this new point based on those nearest neighbors nowif were to expand this circle to include nearest neighborsthat is = get different answer soin that case pick up science fiction and drama movies if let them all vote would end up with classification of science fiction for the new movie instead