Social networks and news outlets entrust content curation to specialised algorithms from the broad family of recommender systems. Companies attempt to increase engagement by connecting users with ideas they are more likely to agree with. Eli Pariser, the author of the term filter bubble, suggested that it might come as a price of narrowing users' outlook. Although empirical studies on algorithmic recommendation showed no reduction in diversity, these algorithms are still a source of concern due to the increased societal polarisation of opinions. Diversity has been widely discussed in the literature, but little attention has been paid to the dynamics of user opinions when influenced by algorithmic curation and social network interaction.This paper describes our empirical research using an Agent-based modelling (ABM) approach to simulate users' emergent behaviour and track their opinions when getting news from news outlets and social networks. We address under which circumstances algorithmic filtering and social network dynamics affect users' innate opinions and which interventions can mitigate the effect.The simulation confirmed that an environment curated by a recommender system did not reduce diversity. The same outcome was observed in a simple social network with items shared among users. However, opinions were less susceptible to change: The difference between users' current and innate opinions was lower than in an environment with users randomly selecting items. Finally, we propose a modification to the collaborative filtering algorithm by selecting items in the boundary of users' latitude of acceptance, increasing the chances to challenge users' opinions.
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This is a repository containing an agent-based model (code, data, documents and results) of Industrial Symbiosis Network implementation. The repository is related to the publication:Lange, K.P., Korevaar, G., Nikolic, I., Herder, P.M., 2021. Actor Behaviour and Robustness of Industrial Symbiosis Networks: An Agent-Based Modelling Approach, 2020:64:4. JASSS. https://doi.org/10.18564/JASSS.4635The purpose of the model is to explore the influence of actor behaviour, combined with environment and business model design, on the survival rates of Industrial Symbiosis Networks (ISN), and the cash flows of the agents. We define an ISN to be robust, when it is able to run for 10 years, without falling apart due to leaving agents.The model simulates the implementation of local waste exchange collaborations for compost production, through the ISN implementation stages of awareness, planning, negotiation, implementation, and evaluation.One central firm plays the role of waste processor in a local composting initiative. This firm negotiates with other firms to become a supplier of their organic residual streams. The waste suppliers in the model can decide to join the initiative, or to have the waste brought to the external waste incinerator. The focal point of the model are the company-level interactions during the implementation or ending of synergies.The model consists of three types of actors, waste suppliers, processor, and incinerators. The modeled waste supplier and processor are part of the ISN. In the model these agent types negotiate and evaluate the outcomes by means of the Theory of Planned Behavior. The modeled incinerator is part of the external environment. This agent acts as the infinite sink of all waste flows, taking up op the waste that is not used in the local composting initiative.
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Agent-based modeling is used for simulating the actions and interactions of autonomous entities aiming to assessing their effects on the system as a whole. At an abstract level, an agent-based model (ABM) is a representation of the many simple agents and interactions among them. The decision making of the agents is based on the rules given to them. In an ABM, the model output is the result of internal decision-making and may differ with alteration in the decision path. On the contrary, with the set of rules embedded in agents, their behavior is modeled to take a ‘certain action’ in a ‘certain situation’. It suggests that the internal decision making behavior of agents is truly responsible for the model output and thus it cannot be ignored while validating ABMs. This research article focuses on the validating agents’ behavior by evaluating decision-making processes of agents. For this purpose, we propose a validation framework based on a participatory simulation game. Using this framework we engage a human player (i.e. a domain stakeholder) to allow us to collect information about choices and validate the behavior of an individual agent. A proof-of-concept game is developed for a city logistics ABM to test the framework.
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De gemeente Den Haag vormt samen met de Haagse Hogeschool, Hogeschool Inholland en de Universiteit Leiden de coalitie van de City Deal Kennis Maken Den Haag. In de eerste fase ligt veel nadruk op het verkennen van de mogelijkheden en ervaringen van stadslabs in wijken. De werkzaamheden richten zich op het verbeteren van de samenwerking tussen de verschillende partners in de Stadslabs, van de aanpak en van het leren in Stadslabs. Los van de Stadslabs zijn er in Den Haag tal van partijen actief in de relatie tussen stad en kennisontwikkeling (onderzoek/onderwijs). De kennis die hierin door de kennispartners opgehaald wordt is niet altijd even goed zichtbaar of vindbaar voor betrokken bewoners, ambtenaren, studenten en docent-onderzoekers. Ook is de koppeling tussen vraag en aanbod niet altijd optimaal. Daarom zal in de tweede fase de ambitie van een goede samenwerkingsstructuur sterker gericht worden op een communicatieve infrastructuur die een brug vormt tussen onderwijs, onderzoek en de stad. De focus wordt breder dan stadslabs alleen. In de eerste fase wordt er een kaart gemaakt van initiatieven van stadslabs en aanverwante activiteiten en er zijn er talkshows rondom het werken in stadslabs. Deze vormen de opmaat voor het tot stand brengen van een breder ecosysteem van onderzoek en onderwijs in relatie tot de stad en een platform voor kennisuitwisseling. Er is een belangrijke rol weggelegd voor studenten in het vormen van de missing link tussen onderzoek en onderwijs en de stad zelf. Andersom kan een goed platform bepalend zijn voor de inrichting van het onderwijs. Er ontstaat een wisselwerking en een wederkerigheid die bijdraagt aan zowel inhoud als organisatie. Om dit te bereiken wordt naast de Stadslabmakelaar en de Stuurgroep het netwerk rondom de City Deal Den Haag uitgebreid met partners van de partners, zoals afdelingen strategie en onderzoek en de Werkplaats Kennis en Innovatie van de Gemeente Den Haag en het Platform Stad.
