On the difficulty to think in ratios: a methodological bias in Stevens’ magnitude estimation procedure

In the field of new psychophysics, the magnitude estimation procedure is one of the most frequently used methods. It requires participants to assess the intensity of a stimulus in relation to a reference. In three studies, we examined whether difficulties of thinking in ratios influence participants’ intensity perceptions. In Study 1, a standard magnitude estimation procedure was compared to an adapted procedure in which the numerical response dimension was reversed so that smaller (larger) numbers indicated brighter (darker) stimuli. In Study 2, participants first had to indicate whether a stimulus was brighter or darker compared to the reference, and only afterwards they estimated the magnitude of this difference, always using ratings above the reference to indicate their perception. In Study 3, we applied the same procedure as in Study 2 to a different physical dimension (red saturation). Results from Study 1 (N = 20) showed that participants in the reversal condition used more (less) extreme ratings for brighter (darker) stimuli compared to the standard condition. Data from the unidirectional method applied in Study 2 (N = 34) suggested a linear psychophysical function for brightness perception. Similar results were found for red saturation in Study 3 (N = 36) with a less curved power function describing the association between objective red saturation and perceived redness perception. We conclude that the typical power functions that emerge when using a standard magnitude estimation procedure might be biased due to difficulties experienced by participants to think in ratios.

Advances in the Science of Asking Questions

In recent decades, research about survey questions has emphasized decision-based approaches. Current research focuses on identifying and systematizing characteristics of questions that are key in researchers’ decisions. We describe important classes of decisions and question characteristics: topic, type of question (e.g., event or behavior, evaluation or judgment), response dimension (e.g., occurrence, frequency, intensity), conceptualization and operationalization of the target object (e.g., how to label the object being asked about and the response dimension), question structure (e.g., use of a filter question, placement in a battery), question form or response format (e.g., yes–no, selection from ordered categories, choice from a list, discrete value), response categories, question wording, and question implementation. We use the framework of question characteristics to summarize key results in active research areas and provide practical recommendations. Progress depends on recognizing how question characteristics co-occur, using a variety of methods and appropriate models, and implementing study designs with strong criteria.

An Improved L-Shaped Method for Solving Process Flexibility Design Problems

Process flexibility, where a plant is able to produce different types of products, is introduced to mitigate mismatch risk caused by demand uncertainties. Thelong chain designproposed by Jordan and Graves in 1995 has been shown to be able to reap most benefits of full-flexibility structure (where each plant is able to produce all products) in balanced systems (where the numbers of products and plants are equal). However, when systems are not balanced or asymmetric or when response dimension is taken into consideration, long chain design may not be the best configuration. Therefore, this paper models the process flexibility design problem in more general settings. The paper considers both balanced and unbalanced systems with asymmetric plants considering response dimension. The problem is formulated as a two-stage stochastic program which is solved by an adapted L-shaped method, combining it with several enhancements. To the best of our knowledge, this is the first time L-shaped method is used to solve the process flexibility design problem. The effectiveness and efficiency of the proposed method and enhancements are evaluated. Finally, the comparison between design methods proposed in this paper and in existing literature shows the superiority of the former.

The Nature of Affective Priming in Music and Speech

The phenomenon of affective priming has caught scientific interest for over 30 years, yet the nature of the affective priming effect remains elusive. This study investigated the underlying mechanism of cross-modal affective priming and the influence of affective incongruence in music and speech on negativities in the N400 time-window. In Experiment 1, participants judged the valence of affective targets (affective categorization). We found that music and speech targets were evaluated faster when preceded by affectively congruent visual word primes, and vice versa. This affective priming effect was accompanied by a significantly larger N400-like effect following incongruent targets. In this experiment, both spreading of activation and response competition could underlie the affective priming effect. In Experiment 2, participants categorized the same affective targets based on nonaffective characteristics. However, as prime valence was irrelevant to the response dimension, affective priming effects could no longer be attributable to response competition. In Experiment 2, affective priming effects were observed neither at the behavioral nor electrophysiological level. The results of this study indicate that both affective music and speech prosody can prime the processing of visual words with emotional connotations, and vice versa. Affective incongruence seems to be associated with N400-like effects during evaluative categorization. The present data further suggest a role of response competition during the affective categorization of music, prosody, and words with emotional connotations.