The Courier, Volume 1, Issue 22, May 2, 1968

Stories: Suit Delays New Campus, Other Financing Sought Poll Finds Pueblo Case Irks Students Most Commuter Bus Service Eyed for Summer Session What’s It Like On An Interim Campus? Alas! A Farewell to Glen Ayre IRC Boom to Continue 3,000 Full-Time Students Expected Here Fall Quarter People: Patrick Hughes, Katie Barbie

Empirical Evaluation of Real World Tournaments

Computational Social Choice (ComSoc) is a rapidly developing field at the intersection of computer science, economics, social choice, and political science. The study of tournaments is fundamental to ComSoc and many results have been published about tournament solution sets and reasoning in tournaments. Theoretical results in ComSoc tend to be worst case and tell us little about performance in practice. To this end we detail some experiments on tournaments using real wold data from soccer and tennis. We make three main contributions to the understanding of tournaments using real world data from English Premier League, the German Bundesliga, and the ATP World Tour: (1) we find that the NP-hard question of finding a seeding for which a given team can win a tournament is easily solvable in real world instances, (2) using detailed and principled methodology from statistical physics we show that our real world data obeys a log-normal distribution; and (3) leveraging our log-normal distribution result and using robust statistical methods, we show that the popular Condorcet Random (CR) tournament model does not generate realistic tournament data.Comment: 2 Figure

The evolution of cooperation: a recreation of Axelrod’s computer tournament

The iterated Prisoner’s Dilemma is a commonly studied game in Game Theory. Many real life situations, such as trench warfare during World War I, can be modeled by such a game. Robert Axelrod implemented a computer tournament in order to determine the best strategy during repeated interactions. Various entries, ranging from very simple to very sophisticated strategies, competed in his tournament. We recreate the tournament using a programming language Matlab and examine the results. Although our results are not entirely identical to Axelrod’s results, we confirm Axelrod’s general findings. In particular, in order for a strategy to be successful, it should be nice, forgiving, relatively easy to understand by its opponents and also retaliatory

Round-robin tournaments with homogeneous rounds

We study single and double round-robin tournaments for n teams, where in each round a fixed number (g) of teams is present and each team present plays a fixed number (m) of matches in this round. In a single, respectively double, round-robin tournament each pair of teams play one, respectively two, matches. In the latter case the two matches should be played in different rounds. We give necessary combinatorial conditions on the triples (n,g,m) for which such round-robin tournaments can exist, and discuss three general construction methods that concern the cases m=1, m=2 and m=g−1. For n≤20 these cases cover 149 of all 173 non-trivial cases that satisfy the necessary conditions. In 147 of these 149 cases a tournament can be constructed. For the remaining 24 cases the tournament does not exist in 2 cases, and is constructed in all other cases. Finally we consider the spreading of rounds for teams, and give some examples where well-spreading is either possible or impossible

Mark Sequences In Digraphs

In Chapter 1, we present a brief introduction of digraphs and some def- initions. Chapter 2 is a review of scores in tournaments and oriented graphs. Also we have obtained several new results on oriented graph scores and we have given a new proof of Avery's theorem on oriented graph scores. In chap- ter 3, we have introduced the concept of marks in multidigraphs, non-negative integers attached to the vertices of multidigraphs. We have obtained several necessary and su cient conditions for sequences of non-negative integers to be mark sequences of some r-digraphs. We have derived stronger inequalities for these marks. Further we have characterized uniquely mark sequences in r-digraphs. This concept of marks has been extended to bipartite multidi- graphs and multipartite multidigraphs in chapter 4. There we have obtained characterizations for mark sequences in these types of multidigraphs and we have given algorithms for constructing corresponding multidigraphs. Chap- ter 5 deals with imbalances and imbalance sequences in digraphs. We have generalized the concept of imbalances to oriented bipartite graphs and have obtained criteria for a pair of integers to be the pair of imbalance sequences of some oriented bipartite graph. We have shown the existence of an oriented bipartite graph whose imbalance set is the given set of integers

Let's (not) talk about sex: The effect of information provision on gender differences in performance under competition

We study how gender differences in performance under competition are affected by the provision of information regarding rival’s gender and/or differences in relative ability. In a laboratory experiment, we use two tasks that differ regarding perceptions about which gender outperforms the other. We observe women’s underperformance only under two conditions: 1) tasks are perceived as favoring men and 2) rivals’ gender is explicitly mentioned. This result can be explained by stereotype-threat being reinforced when explicitly mentioning gender in tasks in which women already consider they are inferior. Omitting information about gender is a safe alternative to avoid women’s underperformance in competition.gender differences, competition, feedback information, gender perception, stereotype-threat

My Way or the Highway: a More Naturalistic Model of Altruism Tested in an Iterative Prisoners' Dilemma

There are three prominent solutions to the Darwinian problem of altruism, kin selection, reciprocal altruism, and trait group selection. Only one, reciprocal altruism, most commonly implemented in game theory as a TIT FOR TAT strategy, is not based on the principle of conditional association. On the contrary, TIT FOR TAT implements conditional altruism in the context of unconditionally determined associates. Simulations based on Axelrod\'s famous tournament have led many to conclude that conditional altruism among unconditional partners lies at the core of much human and animal social behavior. But the results that have been used to support this conclusion are largely artifacts of the structure of the Axelrod tournament, which explicitly disallowed conditional association as a strategy. In this study, we modify the rules of the tournament to permit competition between conditional associates and conditional altruists. We provide evidence that when unconditional altruism is paired with conditional association, a strategy we called MOTH, it can out compete TIT FOR TAT under a wide range of conditions.Game Theory; Altruism; Prisoners' Dilemma; TIT FOR TAT; MOTH; Docking; Netlogo