Module · What learning is✅Knowledge checkCheck: what feedback buys6 questions · Pass at 60%1. Told where each arrow landed, the robot reaches 5.2 cm and stops improving. The wobble alone averages 5.0. What is the 5.0?A bug in the simulation — a perfect archer would average zeroThe floor of the problem: scatter no amount of feedback can removeThe point at which the robot stops being given feedbackThe average of the first ten arrows2. A model has stopped improving on more data. On the evidence of this path, what is the first thing to establish?Whether the algorithm is the right oneWhether more features would helpWhat the best possible score on this problem isWhether the training ran long enough3. Ten labelled arrows bought 95% of everything sixty bought. What does that argue for on a real project?Label a small batch and find out what it changes before buying moreAlways label as much as the budget allowsLabels are not worth paying forSixty examples is the right size for most problems4. Told a number the robot arrives in 10 arrows; told only a category, 18. Both end in the same place. What differs?The destination — a category learner is less accurateHow much each answer contains, and so how many are neededThe algorithm — they are different techniquesThe wobble, which is larger for category feedback5. Asked for eight groups instead of three, the clustering scores BETTER on tightness. What does that tell you about how many groups the data has?That it has eightThat the method has failed and should be re-runNothing — the score improves every time you ask for more, so it cannot chooseThat three was too few and the truth is somewhere between6. With the three causes pushed close together, purity fell to 55% against 33% for guessing — with no error and no warning. What follows?Clustering should not be used on overlapping dataThe method reports low confidence, so watch for that flagGroups always come back looking like groups, so somebody has to judge whether they mean anything55% is still well above guessing, so the result is usableCheck answers← Back to What learning isNext topic →
