Impartial Selection Research Articles

Deterministic Impartial Selection with Weights

In the impartial selection problem, a subset of agents up to a fixed size k among a group of n is to be chosen based on votes cast by the agents themselves. A selection mechanism is impartial if no agent can influence its own chance of being selected by changing its vote. It is α -optimal if, for every instance, the ratio between the votes received by the selected subset is at least a fraction of α of the votes received by the subset of size k with the highest number of votes. We study deterministic impartial mechanisms in a more general setting with arbitrarily weighted votes and provide the first approximation guarantee, roughly 1/⌈2 n / k ⌉. When the number of agents to select is large enough compared to the total number of agents, this yields an improvement on the previously best known approximation ratio of 1/ k for the unweighted setting. We further show that our mechanism can be adapted to the impartial assignment problem, in which multiple sets of up to k agents are to be selected, with a loss in the approximation ratio of 1/2.

Use of proper sampling techniques to research studies

This article extensively examines several sampling strategies, emphasising probability and non-probability sampling approaches. Sampling is essential in research as it influences the degree to which research findings accurately represent and can be applied to a larger population. This article provides a definition of probability sampling and explores its different approaches. The text highlights the benefits of probability sampling, such as its capacity to guarantee impartial selection and facilitate statistical inference. Furthermore, this article delves into the constraints and factors to be taken into account regarding probability sampling, including the need for resources and the possibility of mistakes in sample frames. Subsequently, this paper examined non-probability sampling strategies and investigated methodologies such as convenience sampling, purposive sampling, and quota sampling. This article examines the fundamental concepts of non-probability sampling and highlights its specific applicability in investigating groups that are rare or challenging to access. A comprehensive examination was undertaken to assess the benefits and drawbacks of non probability sampling, with a particular focus on problems such as researcher bias and the absence of statistical generalizability. This article offers a thorough examination of probability and non-probability sampling approaches, allowing scholars to acquire a more profound comprehension of the benefits, constraints, and suitable uses of each approach. It acknowledges the significance of choosing the most suitable sampling method according to research goals, available resources, and the attributes of the target population. In conclusion, this work offers significant resources for researchers who wish to make well-informed choices on sampling procedures in their research.

Impartial Selection with Additive Approximation Guarantees

Impartial selection has recently received much attention within the multi-agent systems community. The task is, given a directed graph representing nominations to the members of a community by other members, to select the member with the highest number of nominations. This seemingly trivial goal becomes challenging when there is an additional impartiality constraint, requiring that no single member can influence her chance of being selected. Recent progress has identified impartial selection rules with optimal approximation ratios. Moreover, it was noted that worst-case instances are graphs with few vertices. Motivated by this fact, we propose the study of additive approximation, the difference between the highest number of nominations and the number of nominations of the selected member, as an alternative measure of the quality of impartial selection. Our positive results include two randomized impartial selection mechanisms which have additive approximation guarantees of $\Theta(\sqrt{n})$ and $\Theta(n^{2/3}\ln^{1/3}n)$ for the two most studied models in the literature, where $n$ denotes the community size. We complement our positive results by providing negative results for various cases. First, we provide a characterization for the interesting class of strong sample mechanisms, which allows us to obtain lower bounds of $n-2$, and of $\Omega(\sqrt{n})$ for their deterministic and randomized variants respectively. Finally, we present a general lower bound of $2$ for all deterministic impartial mechanisms.

Impartial Selection and the Power of Up to Two Choices

We study mechanisms that select members of a set of agents based on nominations by other members and that are impartial in the sense that agents cannot influence their own chance of selection. Prior work has shown that deterministic mechanisms for selecting any fixed number k of agents are severely limited and cannot extract a constant fraction of the nominations of the k most highly nominated agents. We prove here that this impossibility result can be circumvented by allowing the mechanism to sometimes but not always select fewer than k agents. This added flexibility also improves the performance of randomized mechanisms, for which we show a separation between mechanisms that make exactly two or up to two choices and give upper and lower bounds for mechanisms allowed more than two choices.

The paradoxical relationship between fantasy football and NFL consumption: Conflict development and consumer coping mechanisms

Fantasy sport participation represents an increasingly popular consumer experience among the contemporary sport consumption alternatives. Previous work on fantasy sports draws attention to both its positive and negative effects on traditional sport consumption. This study investigates fantasy football participants’ perspectives, meanings, and experiences regarding their fantasy football and NFL consumption behavior. Employing a grounded theory methodology, the study draws on literatures spanning from sport consumption and fantasy sports to consumer co-creation and intrapersonal conflict, and combines them with data collection and analysis. The outcome is a new organizing framework that illustrates why there is conflict between fantasy and favorite team fandom and how fantasy sport participants cope with this conflict. First, the study illustrates that this conflict stems from the non-traditional co-creation opportunities inherent in the empowering fantasy sports experience, which leads to a psychological connection to the fantasy team and players through the feeling of self-achievement. Second, the study identifies various coping strategies that sport consumers employ to manage conflicts with player selection (i.e., safe selection, convergent selection, divergent selection, and impartial selection strategies) and rooting interests (i.e., balanced interest, principal interest-shift, temporal interest-shift, and benefit-seeking interest-shift strategies).

Optimal Impartial Selection

We study a fundamental problem in social choice theory, the selection of a member of a set of agents based on impartial nominations by agents from that set. Studied previously by Alon et al. [Proceedings of TARK, 2011, pp. 101--110] and by Holzman and Moulin [Econometrica, 81 (2013), pp. 173--196], this problem arises when representatives are selected from within a group or when publishing or funding decisions are made based on a process of peer review. Our main result concerns a randomized mechanism that in expectation selects an agent with at least half the maximum number of nominations. This is best possible subject to impartiality and resolves a conjecture of Alon et al. Further results are given for the case where some agent receives many nominations and the case where each agent casts at least one nomination.

A Rawlsian View of CSR and the Game Theory of its Implementation (Part II): Fairness and Equilibrium

This is the second part of an comprehensive essay of the Rawlsian view of corporate social responsibility (CSR thereafter) understood as an extended model of corporate governance and objective function, based on the extension of fiduciary duties owed to the sole owner of the firm to all the company stakeholder (for this definition see part I, Sacconi, 2010a, infra). As in the first part, CSR is also understood as a self-sustaining institution - i.e. as a self-sustaining system of descriptive and normative beliefs consistent with the equilibrium behaviors performed repeatedly by agents in the domain of action of corporate governance (firms and their stakeholders). But equilibria are multiple in the game representing the strategic interaction among the firm and its stakeholders - modeled as a repeated trust game or some similar ‘social dilemma game’ (Ostrom, 1990). Thus asserting that CSR satisfies the Nash equilibrium condition as an institution is not enough. There is also an equilibrium selection problem. This the place where the Rawlsian social contract (Rawls, 1971, 1993) enters again the picture by performing its main role as normative equilibrium selection device from the ex ante perspective: that is, the ex ante impartial selection of a unique equilibrium amongst the many possible in the repeated trust game involving the firms and its stakeholders. Note that this was its second role previously suggested (see section 5 part I, and left to this part where it is treated at length), as distinguished from the role of shaping the players’ expectations so that in the ex post perspective they are able to predict the agreed solution as the result of a cognitive process of beliefs convergence to the equilibrium, which is focused on in part III, (see Sacconi, 2011 and Sacconi 2008).

Ethical Issues, Safety, and Data Integrity in Clinical Trials

Published in 1974, the Belmont Report established the ethical principles for conducting clinical research in the United States. The essential concepts are respect for the research participant, beneficence for society at large, and justice (equal access to participation and equal treatment) toward subjects in a research study. These principles are applied through the use of informed consent, risk/benefit assessment, and the impartial selection of study subjects. Strict adherence to these criteria often results in conflicts of interest, which the investigator must anticipate and manage. Investigators must also be thoroughly acquainted with the principles of Good Clinical Practice and regulatory requirements. Recent implementation of the Privacy Rule now requires the investigator to protect not only the safety but the privacy of the research subject. While the regulatory obligations can appear onerous, strict compliance results in clinical research that is safe, scientifically sound, and ethical.

Design of New Fungicides by Application of the QSAR Technique

The design of new cyclic N-phenylimide fungicides was performed by using a QSAR technique, the Hansch-Fujita method. Furthermore, a computer program called PREHAC, which aids in the impartial selection of substituents for the synthesis of highly bioactive compounds among congeners based on the Hansch-Fujita method, was developed and used effectively for the above-mentioned fungicide design. 3, 5-Dihalo substituents on the benzene ring moiety enhance greatly the antifungal activity of cyclic N-phenylimides against Sclerotinia sclerotiorum, Botrytis cinerea, etc. The relationships between the chemical structure and antifungal activity against B. cinerea of a number of N-phenylsuccinimides and related N-phenyl-1, 2-dimethylcyclopropanedicarboximides having various benzene ring substituents were analyzed for the purpose of the clarification of the physicochemical meaning of 3, 5-dihalo substituents and the search for substitutes for them. The high antifungal activity of the cyclic N-(3, 5-dihalophenyl) imides was rationalized by the hydrophobicity and electron-withdrawing properties of halogen atoms. In addition, the steric bulk of one of the two halogen atoms was revealed to be unfavorable to this activity. It was concluded that 3, 5-dihalo substitutions were most desirable for high activity of this series of compounds. The antifungal activity of N-(3, 5-dichlorophenyl) succinimides and 3-(3, 5-dichlorophenyl)-2, 4-oxazolidinediones, having various substituents on the imido rings, against B. cinerea was related only with the hydrophobicity of the imido ring moieties including the substituents. The 1-isovaleroyl derivative of 3-(3, 5-dichlorophenyl)-2, 4-imidazolidinedione (isovaledione) was designed as a new fungicide against Alternaria diseases. The activity of 1-acyl-3-(3, 5-dichlorophenyl)-2, 4-imidazolidinediones against A. kikuchiana was related parabolically with both the hydrophobicity and steric bulkiness of the aryl moiety substituents. The higher the electroN-donating power of the substituents and the smaller their minimum width in the direction perpendicular to the bond axis, the greater was the activity.

Computer‐Assisted Prediction of Bioactive Compounds Based on the Hansch‐Fujita Analysis

AbstractComputer programs called PREHAC1 and PREHAC2, which aid in the impartial selection of substituents for the synthesis of highly bioactive compounds among congeners based on the Hansch‐Fujita analysis, were developed. The PREHAC1 and 2 programs are for aliphatic and aromatic monosubstituted derivatives and for aromatic disubstituted derivatives, respectively. Thirteen sets of physicochemical parameter values of 408 useful substituents were previously input into a data file as Master Data. PREHAC programs are activated by the input of the coefficients and intercept of the QSAR equation with the corresponding parameter codes, the information on the number of the substituents to be printed out, etc., and then Master Data is searched. Calculated activity values are ranked in descending order and the high‐ranking substituents are printed out according to the specified number. An example is presented to illustrate the programs.

Need for Psychological Services as Perceived by Urban Police Departments

Police departments use psychologists in a variety of different ways. In a national survey of police departments, Parisher, Rios, and Reilley (submitted) found a wide range of services offered by psychologists employed by police departments. Although these results indicate what is now in practice, they do not address either possible areas of growth or existing needs in psychological services as seen by police department personnel. This problem is the focus of the present report. The Parisher survey was sent to 174 urban police departments randomly selected and stratified into four population categories (over 500,000; 250,000-500,000; 125,000250,000; 50,00&125,000). Over 50% ( n = 89) of the selected police departments answered the section of the questionnaire which asked, what services do you feel there is a need in your deparunent? This section was analyzed separately from the major report since it was basically a statement of opinion from the respondents and subjective in narure. The results, though, give some insight into what the police consider to be needed services in their departments. Three services were listed substantially more often than others. The most requested was personal and family counseling for officers (82%) , followed by screening for job applicants ( 7 9 % ) , and workshops in special problems of police work (72%). Other desired services in descending order were development of curriculum for training purposes (51%) , workshops in alcohol and drug abuse (49% ), testing (47%) , workshops in abnormal behavior (44% ), workshops in cultural awareness (40%) , personal and family counseling for victims ( 3 9 % ) , workshops in individual growth (38%), and teaching continuing education courses ( 3 6 % ) . The selections of needs of services were ranked in relatively the same order for all four population categories. Another section of this same survey showed that screening of applicants was most often mentioned as a primary duty of psychologists already working in police departments. It appears that screening is not only a major present responsibility, but also a growing need. Several police deparrments commented on screening, pointing out that competent and impartial selection of police officers is not only desired by the department, but a legal necessity. The research seems to point out that additional psychological services are desired by police departments and that this could conceivably become an area of involvement for psychologists.