When I was a high school student, I entered some National Chemistry Quiz competition – it was basically a school-based multiple-choice exam that took an hour or two to go through.<\/p>\n
I took the question booklet home, and my father was interested in testing his own knowledge, so he asked me to read out questions while he prepared a meal. He’d give his answer, I’d compare it with mine and we’d debate who was right.<\/p>\n
I came to a question which was structured as a dispute between a couple of students over the predicted results of an experiment. It described the experiment, gave both sides of the debate, and asked you to nominate whether one student was right, the other was right or if they were both wrong.<\/p>\n
I started to read the question: “Anthony and Janet are chemistry students and are having an argument about-”<\/p>\n
“Stop there!” interrupted my father. “The girl is correct.”<\/p>\n
I was a little confused, but checked. “Yes, that’s the same answer I gave.” I had carefully considered the chemistry; my father judged the correct answer purely on the climate of political correctness, completely ignoring the chemistry!<\/p>\n
Shaking my head, I continued to the next question: “Anthony and Janet are having another argum-”<\/p>\n
“Stop there!” interrupted my father, again. “This time it is the boy’s turn to be correct.”<\/p>\n
Sure enough that matched my answer.<\/p>\n
Of course, using such techniques is cheating, at least a little bit. In real life, you can’t decide questions of chemistry based on the genders of the chemists. You aren’t learning chemistry here, you are learning exam tricks.<\/p>\n
I am finding myself using a similar exam tricks to solve certain (newspaper-style) puzzles. <\/p>\n
Abstracting away from the specifics of the puzzle (this technique applies to several of them, including Slitherlinks and Hitori), let me describe the type of scenario:<\/p>\n
Suppose the puzzle is to colour in a number of boxes. Each box’s colour is constrained by the colour of some of the other boxes, according to the rules of the puzzle.<\/p>\n
Take a particular box, I don’t know the colour of However, here’s the dodgy trick. I know this puzzle is being published by a careful puzzle-setter who has ensured that there is only one solution. If I am afraid to admit I am worried about the ethics<\/em> of this technique. Am I cheating? This technique is a very powerful optimisation, and yet I feel slightly dirty using it. If I try to solve a real-world problem, I can’t assume there is exactly one answer and that is findable. <\/p>\n I mean, if I am debugging some code, I can’t conclude “the bug can’t be in the third-party component, because if it was, I couldn’t fix it.” Then again, maybe I could ask a pair of students to give their opinion.<\/p>\n","protected":false},"excerpt":{"rendered":" I started to read the question: \u00e2\u20ac\u0153Anthony and Janet are chemistry students and are having an argument about-\u00e2\u20ac\u009d<\/p>\n \u00e2\u20ac\u0153Stop there!\u00e2\u20ac\u009d interrupted my father!<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"","footnotes":""},"categories":[23,46,33,41],"tags":[167,166,49,53,168,91],"class_list":["post-287","post","type-post","status-publish","format-standard","hentry","category-based-on-a-true-story","category-my-father-joe","category-puzzle-solving","category-story-telling","tag-cheating","tag-chemistry","tag-ethics","tag-father","tag-metagaming","tag-puzzles"],"_links":{"self":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/posts\/287","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/comments?post=287"}],"version-history":[{"count":0,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/posts\/287\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/media?parent=287"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/categories?post=287"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.somethinkodd.com\/oddthinking\/wp-json\/wp\/v2\/tags?post=287"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}b1<\/code> – it needs to be coloured black or white according depending on the colour of box b2<\/code>. The rules state that if b2<\/code> is black, b1<\/code> must be white. However, if b2<\/code> is white, the rules don’t constrain b1<\/code>.<\/p>\nb2<\/code> yet, so I don’t know the colour of b1<\/code>. At first blush, it looks like I can’t proceed until I have worked out the colour of b2<\/code>.<\/p>\nb2<\/code> is white, then there are two possible solutions – one with b1<\/code> white, the other with b1<\/code> black. If that was the case, they wouldn’t publish the puzzle. So the fact that this puzzle is published means b2<\/code> is black and b1<\/code> is white.<\/p>\n