Newsletter No. 406

No. 406, 4.11.2012 5 攝於10月初中大一角。把詩寫在黑板和玻璃幕牆上，是由自學中心、香港文學研 究中心、藝術行政主任辦公室及吐露詩社合辦的「書寫力量」發起，希望文學 在校園內遍地開花。 The photo was taken at a corner on campus in early October. Organized by the Independent Learning Centre, the Hong Kong Literature Research Centre, the Office of the Arts Administrator and Tolopoem, ‘The Power of Words’ encouraged members of the CUHK community to write poems on a blackboard or a glass wall to promote the appreciation of literature. 李雅言教授 Prof. Louis Lee 李雅言教授於加拿大太平洋皮爾遜聯合世界書院 畢業，隨後到英國倫敦大學學院修讀心理學，以及 於美國普林斯頓大學深造，取得心理學碩士及博士 學位。李教授於2007年加入中大教育心理學系，現 擔任助理教授，研究興趣包括解難、推理及創意等 高層認知過程。 Prof. Louis Lee holds a BSc from University College London, and a PhD from Princeton University, both in psychology, and is a graduate of Lester B Pearson United World College of the Pacific. Professor Lee joined the Department of Educational Psychology in 2007, and is currently an assistant professor. He is interested in higher- level cognition, in particular problem solving and creativity. and the column are the two constraints on the possible world of answers and the relational complexity would be 2. Lastly, simple tactics may not suffice for difficult puzzles and advanced tactics are called for. Such an advanced tactic would involve two steps: first, the individual infers a set of possibilities for certain cells; then he/she uses these possibilities to eliminate possibilities from other cells. In each of these steps, however, the individual would still rely on simple deductive tactics. In the first experiment designed to test these hypotheses, Professor Lee and his co-authors asked some CUHK students who had never play Sudoku puzzles to tackle three: mildly difficult, difficult, and fiendish ( Figure 1 ) and fill in as many missing numbers as possible within 15 minutes. They were also asked to justify why they had chosen the numbers. It was found that the students spontaneously acquired some deductive tactics within the 15 minutes of their first encounter with Sudoku. The majority of them employed the simple tactics as predicted by the experimenters. The justifications they gave also showed that they were aware of and could articulate on those tactics. In the second experiment, some Princeton students were asked to infer the missing numbers in a series of puzzles with relational complexity ranging from 2 to 5. It was found that the tactics employed rose in difficulty with their relational complexity. With more difficult puzzles, the students discovered that they would have to develop advanced tactics requiring them to keep a record of the possible numbers in the cells. In other words, simple tactics suffice for easier puzzles, but fail with more difficult ones. In the last experiment, 20 CUHK students were divided into two groups for testing the theory of advanced tactics. One was given puzzles similar to the second experiment but with possible numbers given in some of the empty cells ( Figure 2 ). The other was given puzzles with no possibilities provided. In other words, the first step of an advanced tactic is waived for the first group so that they could straightaway use the given possibilities to eliminate the possibilities in the other cells. As predicted, it was faster and easier for those in the first group to solve the puzzles. Professor Lee and his co-authors conclude: ‘In sum, the puzzles establish that logically naïve individuals have the competence to make deductions about abstract matters, and that they enjoy exercising this ability...’ * The conclusion calls in question many psychological theories claiming that deductive reasoning is an ability acquired through education and experience. The observation that some students switched strategies to tackle difficult Sudoku puzzles also tells us something about the mental process of problem-solving or even about human creativity. In fact, Professor Lee has combined his research interest with his passion for tutoring the young, as Dean of Students of Wu Yee Sun College. Through simple but mind-provoking games and puzzles, he encourages his students to think about thinking, analyse its process and develop creative solutions. In his course ‘The Psychology of Thinking and Its Applications’, for instance, he discusses the effectiveness of different hypothesis testing strategies with students through playing the once- popular game MasterMind . The understanding of the human mind with all of its intractabilities and vicissitudes will continue to occupy him in the time to come. 1,4 3,4 1,8 1,3 N 9 5 6 9 7 2 1,3,6 1,3,4, 6 1,3,4, 6 5 3,4 6 7 2,3,4, 6 8 1 2,6,7 5,6,9 4 3 1 5,7,9 2 2,6,7 8 5,7,9 2 3 4 4 8 3 圖二 Figure 2 * N.Y. Louis Lee, Geoffrey P. Goodwin & P.N. Johnson-Laird (2008): The psychological puzzle of Sudoku, Thinking & Reasoning , 14:4, 342–364, at 360. The Power of Words www.facebook.com/ThePowerofWordsCUHK