DOCSLIB.ORG

Autodebias: Learning to Debias for Recommendation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Autodebias: Learning to Debias for Recommendation AutoDebias: Learning to Debias for Recommendation Jiawei Chen1∗, Hande Dong1∗, Yang Qiu1, Xiangnan He1y, Xin Xin2, Liang Chen3, Guli Lin4, Keping Yang4. 1University of Science and Technology of China, 2University of Glasgow, 3Sun Yat-Sen University, 4Alibaba Group. {cjwustc@,donghd@mail.,yangqiu@mail.,hexn@}ustc.edu.cn [email protected],[email protected],{guli.lingl,shaoyao}@taobao.com. ABSTRACT ACM Reference Format: Recommender systems rely on user behavior data like ratings and Jiawei Chen, Hande Dong, Yang Qiu, Xiangnan He, Xin Xin, Liang Chen, Guli Lin and Keping Yang. 2021. AutoDebias: Learning to Debias for Rec- clicks to build personalization model. However, the collected data ommendation. In Proceedings of the 44th International ACM SIGIR Confer- is observational rather than experimental, causing various biases in ence on Research and Development in Information Retrieval (SIGIR ’21), July the data which significantly affect the learned model. Most existing 11–15, 2021, Virtual Event, Canada. ACM, New York, NY, USA, 10 pages. work for recommendation debiasing, such as the inverse propensity https://doi.org/10.1145/3404835.3462919 scoring and imputation approaches, focuses on one or two specific biases, lacking the universal capacity that can account for mixed or 1 INTRODUCTION even unknown biases in the data. Being able to provide personalized suggestions to each user, rec- Towards this research gap, we first analyze the origin of bi- ommender systems (RS) have been widely used in countless online ases from the perspective of risk discrepancy that represents the applications. Recent years have witnessed flourishing publications difference between the expectation empirical risk and the true on recommendation, most of which aim at inventing machine learn- risk. Remarkably, we derive a general learning framework that ing model to fit user behavior data [17, 44, 52]. However, these well summarizes most existing debiasing strategies by specifying models may be deteriorated in real-world RS, as the behavior data some parameters of the general framework. This provides a valu- is often full of biases. In practice, the data is observational rather able opportunity to develop a universal solution for debiasing, than experimental, and is often affected by many factors, including e.g., by learning the debiasing parameters from data. However, but not limited to self-selection of the user (selection bias)[19, 33], the training data lacks important signal of how the data is biased exposure mechanism of the system (exposure bias)[34, 47], public and what the unbiased data looks like. To move this idea forward, opinions (conformity bias)[25, 29] and the display position (position we propose AotoDebias that leverages another (small) set of uni- bias)[22, 23]. These biases make the data deviate from reflecting form data to optimize the debiasing parameters by solving the user true preference. Hence, blindly fitting data without consider- bi-level optimization problem with meta-learning. Through theo- ing the data biases would yield unexpected results, e.g., amplifying retical analyses, we derive the generalization bound for AutoDebias the long-tail effect [1] and previous-model bias [28]. and prove its ability to acquire the appropriate debiasing strategy. Given the wide existence of data biases and their large impact on Extensive experiments on two real datasets and a simulated dataset the learned model, we cannot emphasize too much the importance demonstrated effectiveness of AutoDebias. The code is available at of properly debiasing for practical RS. Existing efforts on recom- https://github.com/DongHande/AutoDebias. mendation (or learning-to-rank) biases can be divided into three major categories: 1) data imputation [19, 42], which assigns pseudo- CCS CONCEPTS labels for missing data to reduce variance, 2) inverse propensity • Information systems ! Recommender systems. scoring (IPS) [39, 47], a counterfactual technique that reweighs the collected data for an expectation-unbiased learning, and 3) genera- KEYWORDS tive modeling [27], which assumes the generation process of data Recommendation, Bias, Debias, Meta-learning and reduces the biases accordingly. Despite their effectiveness in some scenarios, we argue that they suffer from two limitations: • Lacking Universality. These methods are designed for address- ∗ Jiawei Chen and Hande Dong contribute equally to the work. y Xiangnan He is the corresponding author. ing one or two biases of a specific scenario, e.g., IPS for selection bias [39], click model for position bias [12]. Thus, when facing real data that commonly contains multiple types of biases, these Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed methods will fall short. for profit or commercial advantage and that copies bear this notice and the full citation • Lacking Adaptivity. The effectiveness of these methods is guar- on the first page. Copyrights for components of this work owned by others than the anteed only when the debiasing configurations (e.g., pseudo- author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission labels, propensity scores, or data-generating process) are prop- and/or a fee. Request permissions from [email protected]. erly specified. However, obtaining such proper configurations is SIGIR ’21, July 11–15, 2021, Virtual Event, Canada quite difficult, requiring domain expertise that thoroughly un- © 2021 Copyright held by the owner/author(s). Publication rights licensed to ACM. ACM ISBN 978-1-4503-8037-9/21/07...$15.00 derstands the biases in the data and how they affect the model. https://doi.org/10.1145/3404835.3462919 Even worse, the optimal configurations may evolve with time as new users/items/interactions may change the data distribution, Table 1: Notations and Definitions. which has been a nightmare for practitioners to manually tune Notations Annotations the configurations continually. f¹ ºg a biased training set with entries D:, 8:,A: 1≤: ≤ j퐷) j 퐷) Considering the shortcomings of existing work, we believe it is collected from user interaction history a unbiased uniform set with entries f¹D , 8 ,A ºg essential to develop a universal debiasing solution, which not only 퐷 ; ; ; 1≤; ≤ j퐷* j * collected with uniform logging policy accounts for multiple biases and their combinations, but also frees ? ¹D, 8, Aº the data distribution for which 퐷 collected human efforts to identify biases and tune the configurations. To ) ) ? ¹D, 8, Aº the ideal unbiased data distribution achieve this goal, we first review the common biases and debiasing * 5 ¹., .º RS model that maps a user-item pair into the prediction strategies, offering two important insights: (1) Although different \ !ˆ) ¹5 º the empirical risk of 5 on 퐷) biases have different origins and properties, they all can be formu- !¹5 º the true risk of 5 lated as the risk discrepancy between the empirical risk and the true the subspace of U × I × R with constraints: risk, resulting from the inconsistency between the distribution for (1 ?) ¹D, 8, :º ¡ 0,?* ¹D, 8, :º ¡ 0 which the training data is collected and the one used for unbiased the subspace of U × I × R with constraints: (0 test; (2) The success of most recent debiasing strategies can be at- ?) ¹D, 8, :º = 0,?* ¹D, 8, :º ¡ 0 tributed to their specific configurations to offset the discrepancy for model training. Based on the insights, we propose a general • Proposing a new method that leverages uniform data to learn debiasing framework by reducing the risk discrepancy, which sub- optimal debiasing strategy with theoretical guarantees. sumes most debiasing strategies — each strategy can be recovered • Conducting experiments on three types of data (explicit and by specifying the parameters of the framework. This framework implicit feedback, and simulated data of list feedback) to provides a valuable opportunity to develop a universal debiasing so- validate the effectiveness of our proposal. lution for recommendation — we can perform automatic debiasing by learning the debiasing parameters of the framework. 2 PRELIMINARY Now the question lies in how to optimize the debiasing parame- In this section, we formulate the recommendation task and review ters. Obviously, the biased training data lacks important signals of various biases in it from risk discrepancy perspective. how the data is biased and what the unbiased data looks like. To deal with this problem, we propose to leverage another uniform 2.1 Task Formulation data to supervise the learning of debiasing parameter. The uniform U data is assumed to be collected by a random logging policy [39], Suppose we have a recommender system with a user set and an I U I reflecting user preference in an unbiased way. We make full use item set . Let D (or 8) denotes a user (or an item) in (or ). Let 2 R of this important evidence, optimizing the debiasing parameters A denotes the feedback (e.g., rating values, clicks, and retention by minimizing the loss on the uniform data. Specifically, we for- time) given by a user to an item. The collected history behavior data 퐷 can be notated as a set of triplets f¹D , 8 ,A ºg mulate the process as a bi-level optimization problem, where the ) : : : 1≤: ≤ j퐷) j ¹ º debiasing parameters serve as the hyper-parameters for learning generated from an unknown distribution ?) D, 8, A over user-item- U × I × R the recommender model, and optimize debiasing parameters by label space . The task of a recommendation system meta-learning technique [14]. We conduct theoretical analyses on can be stated as follows: learning a recommendation model from the learning framework, proving that: (1) the optimum learned 퐷) so that it can capture user preference and make a high-quality ¹ º under such objective is approximate to the best case where biases recommendation.
Load more

Recommended publications
  • A Task-Based Taxonomy of Cognitive Biases for Information Visualization
    A Task-based Taxonomy of Cognitive Biases for Information Visualization Evanthia Dimara, Steven Franconeri, Catherine Plaisant, Anastasia Bezerianos, and Pierre Dragicevic Three kinds of limitations The Computer The Display 2 Three kinds of limitations The Computer The Display The Human 3 Three kinds of limitations: humans • Human vision ️ has limitations • Human reasoning 易 has limitations The Human 4 ️Perceptual bias Magnitude estimation 5 ️Perceptual bias Magnitude estimation Color perception 6 易 Cognitive bias Behaviors when humans consistently behave irrationally Pohl’s criteria distilled: • Are predictable and consistent • People are unaware they’re doing them • Are not misunderstandings 7 Ambiguity effect, Anchoring or focalism, Anthropocentric thinking, Anthropomorphism or personification, Attentional bias, Attribute substitution, Automation bias, Availability heuristic, Availability cascade, Backfire effect, Bandwagon effect, Base rate fallacy or Base rate neglect, Belief bias, Ben Franklin effect, Berkson's paradox, Bias blind spot, Choice-supportive bias, Clustering illusion, Compassion fade, Confirmation bias, Congruence bias, Conjunction fallacy, Conservatism (belief revision), Continued influence effect, Contrast effect, Courtesy bias, Curse of knowledge, Declinism, Decoy effect, Default effect, Denomination effect, Disposition effect, Distinction bias, Dread aversion, Dunning–Kruger effect, Duration neglect, Empathy gap, End-of-history illusion, Endowment effect, Exaggerated expectation, Experimenter's or expectation bias,
    [Show full text]
  • Cognitive Bias Mitigation: How to Make Decision-Making More Rational?
    Cognitive Bias Mitigation: How to make decision-making more rational? Abstract Cognitive biases distort judgement and adversely impact decision-making, which results in economic inefficiencies. Initial attempts to mitigate these biases met with little success. However, recent studies which used computer games and educational videos to train people to avoid biases (Clegg et al., 2014; Morewedge et al., 2015) showed that this form of training reduced selected cognitive biases by 30 %. In this work I report results of an experiment which investigated the debiasing effects of training on confirmation bias. The debiasing training took the form of a short video which contained information about confirmation bias, its impact on judgement, and mitigation strategies. The results show that participants exhibited confirmation bias both in the selection and processing of information, and that debiasing training effectively decreased the level of confirmation bias by 33 % at the 5% significance level. Key words: Behavioural economics, cognitive bias, confirmation bias, cognitive bias mitigation, confirmation bias mitigation, debiasing JEL classification: D03, D81, Y80 1 Introduction Empirical research has documented a panoply of cognitive biases which impair human judgement and make people depart systematically from models of rational behaviour (Gilovich et al., 2002; Kahneman, 2011; Kahneman & Tversky, 1979; Pohl, 2004). Besides distorted decision-making and judgement in the areas of medicine, law, and military (Nickerson, 1998), cognitive biases can also lead to economic inefficiencies. Slovic et al. (1977) point out how they distort insurance purchases, Hyman Minsky (1982) partly blames psychological factors for economic cycles. Shefrin (2010) argues that confirmation bias and some other cognitive biases were among the significant factors leading to the global financial crisis which broke out in 2008.
    [Show full text]
  • THE ROLE of PUBLICATION SELECTION BIAS in ESTIMATES of the VALUE of a STATISTICAL LIFE W
    THE ROLE OF PUBLICATION SELECTION BIAS IN ESTIMATES OF THE VALUE OF A STATISTICAL LIFE w. k i p vi s c u s i ABSTRACT Meta-regression estimates of the value of a statistical life (VSL) controlling for publication selection bias often yield bias-corrected estimates of VSL that are substantially below the mean VSL estimates. Labor market studies using the more recent Census of Fatal Occu- pational Injuries (CFOI) data are subject to less measurement error and also yield higher bias-corrected estimates than do studies based on earlier fatality rate measures. These re- sultsareborneoutbythefindingsforalargesampleofallVSLestimatesbasedonlabor market studies using CFOI data and for four meta-analysis data sets consisting of the au- thors’ best estimates of VSL. The confidence intervals of the publication bias-corrected estimates of VSL based on the CFOI data include the values that are currently used by government agencies, which are in line with the most precisely estimated values in the literature. KEYWORDS: value of a statistical life, VSL, meta-regression, publication selection bias, Census of Fatal Occupational Injuries, CFOI JEL CLASSIFICATION: I18, K32, J17, J31 1. Introduction The key parameter used in policy contexts to assess the benefits of policies that reduce mortality risks is the value of a statistical life (VSL).1 This measure of the risk-money trade-off for small risks of death serves as the basis for the standard approach used by government agencies to establish monetary benefit values for the predicted reductions in mortality risks from health, safety, and environmental policies. Recent government appli- cations of the VSL have used estimates in the $6 million to $10 million range, where these and all other dollar figures in this article are in 2013 dollars using the Consumer Price In- dex for all Urban Consumers (CPI-U).
    [Show full text]
  • Bias and Fairness in NLP
    Bias and Fairness in NLP Margaret Mitchell Kai-Wei Chang Vicente Ordóñez Román Google Brain UCLA University of Virginia Vinodkumar Prabhakaran Google Brain Tutorial Outline ● Part 1: Cognitive Biases / Data Biases / Bias laundering ● Part 2: Bias in NLP and Mitigation Approaches ● Part 3: Building Fair and Robust Representations for Vision and Language ● Part 4: Conclusion and Discussion “Bias Laundering” Cognitive Biases, Data Biases, and ML Vinodkumar Prabhakaran Margaret Mitchell Google Brain Google Brain Andrew Emily Simone Parker Lucy Ben Elena Deb Timnit Gebru Zaldivar Denton Wu Barnes Vasserman Hutchinson Spitzer Raji Adrian Brian Dirk Josh Alex Blake Hee Jung Hartwig Blaise Benton Zhang Hovy Lovejoy Beutel Lemoine Ryu Adam Agüera y Arcas What’s in this tutorial ● Motivation for Fairness research in NLP ● How and why NLP models may be unfair ● Various types of NLP fairness issues and mitigation approaches ● What can/should we do? What’s NOT in this tutorial ● Definitive answers to fairness/ethical questions ● Prescriptive solutions to fix ML/NLP (un)fairness What do you see? What do you see? ● Bananas What do you see? ● Bananas ● Stickers What do you see? ● Bananas ● Stickers ● Dole Bananas What do you see? ● Bananas ● Stickers ● Dole Bananas ● Bananas at a store What do you see? ● Bananas ● Stickers ● Dole Bananas ● Bananas at a store ● Bananas on shelves What do you see? ● Bananas ● Stickers ● Dole Bananas ● Bananas at a store ● Bananas on shelves ● Bunches of bananas What do you see? ● Bananas ● Stickers ● Dole Bananas ● Bananas
    [Show full text]
  • Why So Confident? the Influence of Outcome Desirability on Selective Exposure and Likelihood Judgment
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by The University of North Carolina at Greensboro Archived version from NCDOCKS Institutional Repository http://libres.uncg.edu/ir/asu/ Why so confident? The influence of outcome desirability on selective exposure and likelihood judgment Authors Paul D. Windschitl , Aaron M. Scherer a, Andrew R. Smith , Jason P. Rose Abstract Previous studies that have directly manipulated outcome desirability have often found little effect on likelihood judgments (i.e., no desirability bias or wishful thinking). The present studies tested whether selections of new information about outcomes would be impacted by outcome desirability, thereby biasing likelihood judgments. In Study 1, participants made predictions about novel outcomes and then selected additional information to read from a buffet. They favored information supporting their prediction, and this fueled an increase in confidence. Studies 2 and 3 directly manipulated outcome desirability through monetary means. If a target outcome (randomly preselected) was made especially desirable, then participants tended to select information that supported the outcome. If made undesirable, less supporting information was selected. Selection bias was again linked to subsequent likelihood judgments. These results constitute novel evidence for the role of selective exposure in cases of overconfidence and desirability bias in likelihood judgments. Paul D. Windschitl , Aaron M. Scherer a, Andrew R. Smith , Jason P. Rose (2013) "Why so confident? The influence of outcome desirability on selective exposure and likelihood judgment" Organizational Behavior and Human Decision Processes 120 (2013) 73–86 (ISSN: 0749-5978) Version of Record available @ DOI: (http://dx.doi.org/10.1016/j.obhdp.2012.10.002) Why so confident? The influence of outcome desirability on selective exposure and likelihood judgment q a,⇑ a c b Paul D.
    [Show full text]
  • Correcting Sampling Bias in Non-Market Valuation with Kernel Mean Matching
    CORRECTING SAMPLING BIAS IN NON-MARKET VALUATION WITH KERNEL MEAN MATCHING Rui Zhang Department of Agricultural and Applied Economics University of Georgia [email protected] Selected Paper prepared for presentation at the 2017 Agricultural & Applied Economics Association Annual Meeting, Chicago, Illinois, July 30 - August 1 Copyright 2017 by Rui Zhang. All rights reserved. Readers may make verbatim copies of this document for non-commercial purposes by any means, provided that this copyright notice appears on all such copies. Abstract Non-response is common in surveys used in non-market valuation studies and can bias the parameter estimates and mean willingness to pay (WTP) estimates. One approach to correct this bias is to reweight the sample so that the distribution of the characteristic variables of the sample can match that of the population. We use a machine learning algorism Kernel Mean Matching (KMM) to produce resampling weights in a non-parametric manner. We test KMM’s performance through Monte Carlo simulations under multiple scenarios and show that KMM can effectively correct mean WTP estimates, especially when the sample size is small and sampling process depends on covariates. We also confirm KMM’s robustness to skewed bid design and model misspecification. Key Words: contingent valuation, Kernel Mean Matching, non-response, bias correction, willingness to pay 2 1. Introduction Nonrandom sampling can bias the contingent valuation estimates in two ways. Firstly, when the sample selection process depends on the covariate, the WTP estimates are biased due to the divergence between the covariate distributions of the sample and the population, even the parameter estimates are consistent; this is usually called non-response bias.
    [Show full text]
  • Evaluation of Selection Bias in an Internet-Based Study of Pregnancy Planners
    HHS Public Access Author manuscript Author ManuscriptAuthor Manuscript Author Epidemiology Manuscript Author . Author manuscript; Manuscript Author available in PMC 2016 April 04. Published in final edited form as: Epidemiology. 2016 January ; 27(1): 98–104. doi:10.1097/EDE.0000000000000400. Evaluation of Selection Bias in an Internet-based Study of Pregnancy Planners Elizabeth E. Hatcha, Kristen A. Hahna, Lauren A. Wisea, Ellen M. Mikkelsenb, Ramya Kumara, Matthew P. Foxa, Daniel R. Brooksa, Anders H. Riisb, Henrik Toft Sorensenb, and Kenneth J. Rothmana,c aDepartment of Epidemiology, Boston University School of Public Health, Boston, MA bDepartment of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark cRTI Health Solutions, Durham, NC Abstract Selection bias is a potential concern in all epidemiologic studies, but it is usually difficult to assess. Recently, concerns have been raised that internet-based prospective cohort studies may be particularly prone to selection bias. Although use of the internet is efficient and facilitates recruitment of subjects that are otherwise difficult to enroll, any compromise in internal validity would be of great concern. Few studies have evaluated selection bias in internet-based prospective cohort studies. Using data from the Danish Medical Birth Registry from 2008 to 2012, we compared six well-known perinatal associations (e.g., smoking and birth weight) in an inter-net- based preconception cohort (Snart Gravid n = 4,801) with the total population of singleton live births in the registry (n = 239,791). We used log-binomial models to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for each association. We found that most results in both populations were very similar.
    [Show full text]
  • Testing for Selection Bias IZA DP No
    IZA DP No. 8455 Testing for Selection Bias Joonhwi Joo Robert LaLonde September 2014 DISCUSSION PAPER SERIES Forschungsinstitut zur Zukunft der Arbeit Institute for the Study of Labor Testing for Selection Bias Joonhwi Joo University of Chicago Robert LaLonde University of Chicago and IZA Discussion Paper No. 8455 September 2014 IZA P.O. Box 7240 53072 Bonn Germany Phone: +49-228-3894-0 Fax: +49-228-3894-180 E-mail: [email protected] Any opinions expressed here are those of the author(s) and not those of IZA. Research published in this series may include views on policy, but the institute itself takes no institutional policy positions. The IZA research network is committed to the IZA Guiding Principles of Research Integrity. The Institute for the Study of Labor (IZA) in Bonn is a local and virtual international research center and a place of communication between science, politics and business. IZA is an independent nonprofit organization supported by Deutsche Post Foundation. The center is associated with the University of Bonn and offers a stimulating research environment through its international network, workshops and conferences, data service, project support, research visits and doctoral program. IZA engages in (i) original and internationally competitive research in all fields of labor economics, (ii) development of policy concepts, and (iii) dissemination of research results and concepts to the interested public. IZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author. IZA Discussion Paper No.
    [Show full text]
  • Correcting Sample Selection Bias by Unlabeled Data
    Correcting Sample Selection Bias by Unlabeled Data Jiayuan Huang Alexander J. Smola Arthur Gretton School of Computer Science NICTA, ANU MPI for Biological Cybernetics Univ. of Waterloo, Canada Canberra, Australia T¨ubingen, Germany [email protected] [email protected] [email protected] Karsten M. Borgwardt Bernhard Scholkopf¨ Ludwig-Maximilians-University MPI for Biological Cybernetics Munich, Germany T¨ubingen, Germany [email protected]fi.lmu.de [email protected] Abstract We consider the scenario where training and test data are drawn from different distributions, commonly referred to as sample selection bias. Most algorithms for this setting try to first recover sampling distributions and then make appro- priate corrections based on the distribution estimate. We present a nonparametric method which directly produces resampling weights without distribution estima- tion. Our method works by matching distributions between training and testing sets in feature space. Experimental results demonstrate that our method works well in practice. 1 Introduction The default assumption in many learning scenarios is that training and test data are independently and identically (iid) drawn from the same distribution. When the distributions on training and test set do not match, we are facing sample selection bias or covariate shift. Specifically, given a domain of patterns X and labels Y, we obtain training samples Z = (x , y ),..., (x , y ) X Y from { 1 1 m m } ⊆ × a Borel probability distribution Pr(x, y), and test samples Z′ = (x′ , y′ ),..., (x′ ′ , y′ ′ ) X Y { 1 1 m m } ⊆ × drawn from another such distribution Pr′(x, y). Although there exists previous work addressing this problem [2, 5, 8, 9, 12, 16, 20], sample selection bias is typically ignored in standard estimation algorithms.
    [Show full text]
  • The Bias Bias in Behavioral Economics
    Review of Behavioral Economics, 2018, 5: 303–336 The Bias Bias in Behavioral Economics Gerd Gigerenzer∗ Max Planck Institute for Human Development, Lentzeallee 94, 14195 Berlin, Germany; [email protected] ABSTRACT Behavioral economics began with the intention of eliminating the psychological blind spot in rational choice theory and ended up portraying psychology as the study of irrationality. In its portrayal, people have systematic cognitive biases that are not only as persis- tent as visual illusions but also costly in real life—meaning that governmental paternalism is called upon to steer people with the help of “nudges.” These biases have since attained the status of truisms. In contrast, I show that such a view of human nature is tainted by a “bias bias,” the tendency to spot biases even when there are none. This may occur by failing to notice when small sample statistics differ from large sample statistics, mistaking people’s ran- dom error for systematic error, or confusing intelligent inferences with logical errors. Unknown to most economists, much of psycho- logical research reveals a different portrayal, where people appear to have largely fine-tuned intuitions about chance, frequency, and framing. A systematic review of the literature shows little evidence that the alleged biases are potentially costly in terms of less health, wealth, or happiness. Getting rid of the bias bias is a precondition for psychology to play a positive role in economics. Keywords: Behavioral economics, Biases, Bounded Rationality, Imperfect information Behavioral economics began with the intention of eliminating the psycho- logical blind spot in rational choice theory and ended up portraying psychology as the source of irrationality.
    [Show full text]
  • Do Visitors of Product Evaluation Portals Select Reviews in a Biased Manner? Cyberpsychology: Journal of Psychosocial Research on Cyberspace, 15(1), Article 4
    Winter, K., Zapf, B., Hütter, M., Tichy, N., & Sassenberg, K. (2021). Selective exposure in action: Do visitors of product evaluation portals select reviews in a biased manner? Cyberpsychology: Journal of Psychosocial Research on Cyberspace, 15(1), article 4. https://doi.org/10.5817/CP2021-1-4 Selective Exposure in Action: Do Visitors of Product Evaluation Portals Select Reviews in a Biased Manner? Kevin Winter1, Birka Zapf1,2, Mandy Hütter2, Nicolas Tichy3, & Kai Sassenberg1,2 1 Leibniz-Institut für Wissensmedien, Tübingen, Germany 2 University of Tübingen, Tübingen, Germany 3 Ludwig Maximilian University of Munich, Munich, Germany Abstract Most people in industrialized countries regularly purchase products online. Consumers often rely on previous customers’ reviews to make purchasing decisions. The current research investigates whether potential online customers select these reviews in a biased way and whether typical interface properties of product evaluation portals foster biased selection. Based on selective exposure research, potential online customers should have a bias towards selecting positive reviews when they have an initial preference for a product. We tested this prediction across five studies (total N = 1376) while manipulating several typical properties of the review selection interface that should – according to earlier findings – facilitate biased selection. Across all studies, we found some evidence for a bias in favor of selecting positive reviews, but the aggregated effect was non-significant in an internal meta- analysis. Contrary to our hypothesis and not replicating previous research, none of the interface properties that were assumed to increase biased selection led to the predicted effects. Overall, the current research suggests that biased information selection, which has regularly been found in many other contexts, only plays a minor role in online review selection.
    [Show full text]
  • Bias and Confounding • Describe the Key Types of Bias
    M1 - PopMed OBJECTIVES Bias and Confounding • Describe the key types of bias • Identify sources of bias in study design, data collection and analysis Saba Masho, MD, MPH, DrPH Department of Epidemiology and Community Health • Identify confounders and methods for [email protected] controlling confounders 1 2 Bias Types: • Bias is any systematic error in an epidemiologic study that results in an 1. Selection incorrect estimate of association between risk factor and outcome. 2. Information/measurement • It is introduced in the design of the study including, data collection, analysis, 3. Confounding interpretation, publication or review of data. • It is impossible to correct for bias during the analysis and may also be hard to evaluate. Thus, studies need to be carefully designed. 3 4 SELECTION BIAS SELECTION BIAS • A systematic error that arises in the process of selecting the study populations • May also occur when membership in one group differs systematically from the general population or • May occur when different criteria is used to select control group, called membership bias cases/controls or exposed/non exposed – E.g. selecting cases from inner hospitals and controls from – E.g. A study in uterine cancer excluding patients with sub-urban hospitals hysterectomy from cases but not from control • The differences in hospital admission between cases • Detection bias: occurs when the risk factor under and controls may conceal an association in a study, investigation requires thorough diagnostic this is called “Berkson’s bias” or “admission
    [Show full text]