A study on a mixed stopping strategy for total recall tasks

How do we calculate how many relevant documents are in a collection? In this abstract, we discuss our line of research about total recall systems such as interactive system for systematic reviews based on an active learning framework [4\u20136]. In particular, we will present 1) the problem in mathematical terms, and 2) the experiments of an interactive system that continuously monitors the costs of reviewing additional documents and suggests the user whether to continue or not in the search based on the available remaining resources. We will discuss the results of this system on the ongoing CLEF 2019 eHealth task

The Relationship Between Risk Attitudes and Heuristics in Search Tasks: A Laboratory Experiment

Experimental studies of search behavior suggest that individuals stop searching earlier than predicted by the optimal, risk-neutral stopping rule. Such behavior could be generated by two different classes of decision rules: rules that are optimal conditional on utility functions departing from risk neutrality, or heuristics derived from limited cognitive processing capacities and satisfycing. To discriminate among these two possibilities, we conduct an experiment that consists of a standard search task as well as a lottery task designed to elicit utility functions. We find that search heuristics are not related to measures of risk aversion, but to measures of loss aversion

The Relationship Between Risk Attitudes and Heuristics in Search Tasks: A Laboratory Experiment

The existing evidence from laboratory experiments suggests that relatively simple heuristics describe observed search behavior better than the optimal stopping rule derived under risk neutrality. Such behavior could be generated by two entirely different classes of decision rules: (i) rules that are optimal conditional on utility functions that depart from risk neutrality or (ii) heuristics that derive from limited cognitive processing capacities and satisfycing. In this paper, we develop and test search models that depart from the standard assumption of risk neutrality in order to distinguish these two possibilities. In our experiment, we present subjects not only with a standard search task, but also with a series of lottery tasks that serve to elicit the shape of their utility functions. We do not find a relationship between behavior in the search task and measures of risk aversion. Our data suggest, however, that loss aversion is important for explaining search behavior.

Search behaviour with reference point preferences:

People are heterogeneous with respect to their behaviour in sequential decision situations. This paper develops models for search behaviour under the assumption of expected-utility maximisation and a new search model that assumes sequential updating of utility reference points during the search process. I find experimental evidence that supports the new reference point model: Individual loss aversion is systematically related to the observed search behaviour in a way that is consistent with the predictions of the reference point model. Risk attitude is not related to search behaviour. The finding that many people set reference points in sequential decision tasks is of interest in, e.g. consumer economics, labour economics, finance, and decision theory.

The Relationship Between Risk Attitudes and Heuristics in Search Tasks: A Laboratory Experiment

Experimental studies of search behavior suggest that individuals stop searching earlier than predicted by the optimal, risk-neutral stopping rule. Such behavior could be generated by two different classes of decision rules: rules that are optimal conditional on utility functions departing from risk neutrality, or heuristics derived from limited cognitive processing capacities and satisfycing. To discriminate among these two possibilities, we conduct an experiment that consists of a standard search task as well as a lottery task designed to elicit utility functions. We find that search heuristics are not related to measures of risk aversion, but to measures of loss aversion.search; heuristics; utility function elicitation; risk attitudes; prospect theory

Are Consumers Fooled by Discounts? An Experimental Test in a Consumer Search Environment

In this paper we investigate experimentally if people search optimally and how price promotions influence search behavior. We implement a sequential search task with exogenous price dispersion in a baseline treatment and introduce discounts in two experimental treatments. We find that search behavior is roughly consistent with optimal search but also observe some discount biases. If subjects don't know in advance where discounts are offered the purchase probability is increased by 19 percentage points in shops with discounts, even after controlling for the benefit of the discount and for risk preferences. If consumers know in advance where discounts are given then the bias is only weakly significant and much smaller (7 percentage points).Consumer Search Theory, Search Cost, Price Promotion