2019-08-23, Giese, Helge, Neth, Hansjörg, Gaissmaier, Wolfgang

Einleitung:
In psychologischen Theorien zur Gesundheitsverhaltensförderung nehmen soziale Konstrukte, wie z.B. Normwahrnehmung, einen zentralen Platz ein. Das tatsächliche Verhalten in sozialen Kontexten wird dabei oft außer Acht gelassen. In diesem Vortrag wird daher darauf eingegangen, inwiefern Normwahrnehmungen innerhalb eines sozialen Netzwerks soziale Einflüsse beim Alkoholkonsum erklären können.

Methoden:
109 Psychologiestudierende wurden zu drei Messzeitpunkten innerhalb des ersten Semesters zu ihren alkoholbezogenen Kognitionen, Alkoholkonsum und Freunden innerhalb des Semesters befragt. Zur Vorhersage sozialer Einflüsse auf Alkoholkonsum und Freundschaftsentwicklungen wurden RSiena Modelle angewandt.

Ergebnisse:
Der durchschnittliche Alkoholkonsum von Freunden im Semester sagte den Konsum zum nächsten Messzeitpunkt auch nach der Kontrolle von Kognitionen, wie der Wahrnehmung vom Verhalten der Freunde, vorher (b = 1,89, OR = 6,64, 95%CI [1,28; 34,50], p = 0,022).

Diskussion:
Soziale Einflüsse beim Alkoholkonsum von Erstsemestern können nicht vollständig durch kognitive Konstrukte wie Normwahrnehmungen aufgeklärt werden. Dies suggeriert, dass es zusätzliche soziale Kontexteinflüsse gibt.

2017, Mousavi, Shabnam, Meder, Björn, Neth, Hansjörg, Kheirandish, Reza

2016-03, Neth, Hansjörg, Sims, Chris R., Gray, Wayne D.

How can we study bounded rationality? We answer this question by proposing rational task analysis (RTA)—a systematic approach that prevents experimental researchers from drawing premature conclusions regarding the (ir-)rationality of agents. RTA is a methodology and perspective that is anchored in the notion of bounded rationality and aids in the unbiased interpretation of results and the design of more conclusive experimental paradigms. RTA focuses on concrete tasks as the primary interface between agents and environments and requires explicating essential task elements, specifying rational norms, and bracketing the range of possible performance, before contrasting various benchmarks with actual performance. After describing RTA’s core components we illustrate its use in three case studies that examine human memory updating, multitasking behavior, and melioration. We discuss RTA’s characteristic elements and limitations by comparing it to related approaches. We conclude that RTA provides a useful tool to render the study of bounded rationality more transparent and less prone to theoretical confusion.

2014, Neth, Hansjörg, Meder, Björn, Kothiyal, Amit, Gigerenzer, Gerd

What - if anything - can psychology and decision science contribute to risk management in financial institutions? The turmoils of recent economic crises undermine the assumptions of classical economic models and threaten to dethrone Homo oeconomicus, who aims to make decisions by weighing and integrating all available information. But rather than proposing to replace the rational actor model with some notion of biased, fundamentally flawed and irrational agents, we advocate the alternative notion of Homo heuristicus, who uses simple, but ecologically rational strategies to make sound and robust decisions. Based on the conceptual distinction between risky and uncertain environments this paper presents theoretical and empirical evidence that boundedly rational agents prefer simple heuristics over more flexible models. We provide examples of successful heuristics, explain when and why heuristics work well, and illustrate these insights with a fast and frugal decision tree that helps to identify fragile banks. We conclude that all members of the financial community will benefit from simpler and more transparent products and regulations.

2018, Neth, Hansjörg, Gaisbauer, Felix, Gradwohl, Nico, Gaissmaier, Wolfgang

Risk-related information — like the prevalence of conditions and the sensitivity and specificity of diagnostic tests or treatment decisions — can be expressed in terms of probabilities or frequencies. By providing a toolbox of methods and metrics, riskyr computes, translates, and displays risk-related information in a variety of ways. Offering multiple complementary perspectives on the interplay between key parameters renders teaching and training of risk literacy more transparent.

2017, Phillips, Nathaniel D., Neth, Hansjörg, Woike, Jan K., Gaissmaier, Wolfgang

Fast-and-frugal trees (FFTs) are simple algorithms that facilitate efficient and accurate decisions based on limited information. But despite their successful use in many applied domains, there is no widely available toolbox that allows anyone to easily create, visualize, and evaluate FFTs. We fill this gap by introducing the R package FFTrees. In this paper, we explain how FFTs work, introduce a new class of algorithms called fan for constructing FFTs, and provide a tutorial for using the FFTrees package. We then conduct a simulation across ten real-world datasets to test how well FFTs created by FFTrees can predict data. Simulation results show that FFTs created by FFTrees can predict data as well as popular classification algorithms such as regression and random forests, while remaining simple enough for anyone to understand and use.

2016, Gaissmaier, Wolfgang, Neth, Hansjörg

2017-08-14, Neth, Hansjörg, Gaissmaier, Wolfgang

2017, Veksler, Bella Z., Boyd, Rachel, Myers, Christopher W., Gunzelmann, Glenn, Neth, Hansjörg, Gray, Wayne D.

Visual working memory (VWM) is a construct hypothesized to store a small amount of accurate perceptual information that can be brought to bear on a task. Much research concerns the construct's capacity and the precision of the information stored. Two prominent theories of VWM representation have emerged: slot-based and continuous-resource mechanisms. Prior modeling work suggests that a continuous resource that varies over trials with variable capacity and a potential to make localization errors best accounts for the empirical data. Questions remain regarding the variability in VWM capacity and precision. Using a novel eye-tracking paradigm, we demonstrate that VWM facilitates search and exhibits effects of fixation frequency and recency, particularly for prior targets. Whereas slot-based memory models cannot account for the human data, a novel continuous-resource model does capture the behavioral and eye tracking data, and identifies the relevant resource as item activation.

2015-05-15, Neth, Hansjörg, Gigerenzer, Gerd

We distinguish between situations of risk, where all options, consequences, and probabilities are known, and situations of uncertainty, where they are not. Probability theory and statistics are the best tools for deciding under risk but not under uncertainty, which characterizes most relevant problems that humans have to solve. Uncertainty requires simple heuristics that are robust rather than optimal. We propose to think of the mind as an adaptive toolbox and introduce the descriptive study of heuristics, their building blocks, and the core capacities they exploit. The question of which heuristic to select for which class of problems is the topic of the normative study of ecological rationality. We discuss earlier views on the nature of heuristics that maintained that heuristics are always less accurate because they ignore information and demand less effort. Contrary to this accuracy–effort trade-off view, heuristics can lead to more accurate inferences—under uncertainty—than strategies that use more information and computation. The study of heuristics opens up a new perspective on the nature of both cognition and rationality. In a world of uncertainty, Homo sapiens might well be called Homo heuristicus.