Inferential misconceptions and replication crisis

Misinterpretations of the p value and the introduction of bias through arbitrary analytical choices have been discussed in the literature for decades. Nonetheless, they seem to have persisted in empirical research, and criticisms of p value misuses have increased in the recent past due to the non-replicability of many studies. Unfortunately, the critical concerns that have been raised in the literature are scattered over many disciplines, often linguistically confusing, and differing in their main reasons for criticisms. Misuses and misinterpretations of the p value are currently being discussed intensely under the label “replication crisis” in many academic disciplines and journals, ranging from specialized scientific journals to Nature and Science. In a drastic response to the crisis, the editors of the journal Basic and Applied Social Psychology even decided to ban the use of p values from future publications at the beginning of 2015, a fact that has certainly added fuel to the discussions in the relevant scientific forums. Finally, in early March, the American Statistical Association released a brief formal statement on p values that explicitly addresses misuses and misinterpretations. In this context, we systematize the most serious flaws related to the p value and discuss suggestions of how to prevent them and reduce the rate of false discoveries in the future

Sensorimotor Experience Influences Recovery of Forelimb Abilities but Not Tissue Loss after Focal Cortical Compression in Adult Rats

Sensorimotor activity has been shown to play a key role in functional outcome after extensive brain damage. This study was aimed at assessing the influence of sensorimotor experience through subject-environment interactions on the time course of both lesion and gliosis volumes as well as on the recovery of forelimb sensorimotor abilities following focal cortical injury. The lesion consisted of a cortical compression targeting the forepaw representational area within the primary somatosensory cortex of adult rats. After the cortical lesion, rats were randomly subjected to various postlesion conditions: unilateral C5–C6 dorsal root transection depriving the contralateral cortex from forepaw somatosensory inputs, standard housing or an enriched environment promoting sensorimotor experience and social interactions. Behavioral tests were used to assess forelimb placement during locomotion, forelimb-use asymmetry, and forepaw tactile sensitivity. For each group, the time course of tissue loss was described and the gliosis volume over the first postoperative month was evaluated using an unbiased stereological method. Consistent with previous studies, recovery of behavioral abilities was found to depend on post-injury experience. Indeed, increased sensorimotor activity initiated early in an enriched environment induced a rapid and more complete behavioral recovery compared with standard housing. In contrast, severe deprivation of peripheral sensory inputs led to a delayed and only partial sensorimotor recovery. The dorsal rhizotomy was found to increase the perilesional gliosis in comparison to standard or enriched environments. These findings provide further evidence that early sensory experience has a beneficial influence on the onset and time course of functional recovery after focal brain injury

Covid-19 triage in the emergency department 2.0: how analytics and AI transform a human-made algorithm for the prediction of clinical pathways

The Covid-19 pandemic has pushed many hospitals to their capacity limits. Therefore, a triage of patients has been discussed controversially primarily through an ethical perspective. The term triage contains many aspects such as urgency of treatment, severity of the disease and pre-existing conditions, access to critical care, or the classification of patients regarding subsequent clinical pathways starting from the emergency department. The determination of the pathways is important not only for patient care, but also for capacity planning in hospitals. We examine the performance of a human-made triage algorithm for clinical pathways which is considered a guideline for emergency departments in Germany based on a large multicenter dataset with over 4,000 European Covid-19 patients from the LEOSS registry. We find an accuracy of 28 percent and approximately 15 percent sensitivity for the ward class. The results serve as a benchmark for our extensions including an additional category of palliative care as a new label, analytics, AI, XAI, and interactive techniques. We find significant potential of analytics and AI in Covid-19 triage regarding accuracy, sensitivity, and other performance metrics whilst our interactive human-AI algorithm shows superior performance with approximately 73 percent accuracy and up to 76 percent sensitivity. The results are independent of the data preparation process regarding the imputation of missing values or grouping of comorbidities. In addition, we find that the consideration of an additional label palliative care does not improve the results

Sample size calculations in economic RCTs: following clinical studies?

Clinical studies and economic experiments are often conducted utilizing randomized controlled trials. In contrast to clinical drug trials, sample size calculation has rarely been carried out by experimental economists. Using simple examples for illustration purposes, I discuss pros and cons of using sample size calculations in experimental economics

Sven Gruener's Quick Files

The Quick Files feature was discontinued and it’s files were migrated into this Project on March 11, 2022. The file URL’s will still resolve properly, and the Quick Files logs are available in the Project’s Recent Activity

A comment on randomization checks in economics experiments

This note deals with baseline comparisons in randomized controlled trials in economics. Although widely spread in the literature, resorting to p-values is an inadequate procedure to assess whether randomization was successfully carried out. Instead, it is promising to use standardized differences. In addition, challenges to evaluate the quality of randomization appear if self-selection is systematically different across the com-pared treatments

An empirical study on Internet-based false news stories: experiences, problem awareness, and responsibilities

The Internet has significantly reduced the marginal costs of generating and disseminating information. The human information portfolio includes correct and incorrect information. False news stories constitute a challenge for our democracy. Therefore, scientists are increasingly interested in redesigning the information ecosystem. This paper addresses the problem awareness of university students in the realm of false news stories. With the help of a questionnaire, we seek for interesting correlations to generate hypotheses that can be analyzed in further studies with new data (i.e., exploratory study). The hypotheses read as follows: (i) Facebook users are more likely to suspect to be in touch with false news stories if they are interested in politics. People are less likely to assume to deal with false news stories the stronger they trust in others and the more emphasis they put on the opinions of others, (ii) False news stories are perceived as a problem at the societal level but not at the individual level, (iii) Men more often than women believe to be in touch with false news stories; men overestimate their ability to spot false news stories. People who fear false news stories are likely to believe that they could detect such information better than the average, and (iv) People see operators of platforms to be in charge of false news stories; people seem to have less confidence in the government

Health and environmental implications of food consumption: What do people want to know?

Contradicting rational choice, people sometimes do not want information even if it is free (information avoidance). People may want to enjoy the pleasure of unhealthy food wrapped in plastic packaging today and do not want to be informed about the long-term consequences for their health and the environment. Using a quota-representative survey of the German population (N=1,000), we aim to identify behavioral determinants that are associated with information avoidance in the food sector. Participants are asked to what extent they do (not) want to receive information in the realm of the food sector using 10 different hypothetical situations. Information avoidance is measured on a 5-point Likert scale (1=“Definitely want to know” to 5=“Definitely don’t want to know”). This procedure ensures that relatively poor people do not give systematically biased answers due to a lack of financial resources. Our findings can be summarized as follows: First, preferences/personality traits can partly predict information avoidance. For example, positive reciprocity, altruism, internal locus of control, and self-esteem are negatively associated with information avoidance. The relevance of trust and patience is limited to environmental-related consequences. Second, individuals are less willing to forgo information the better they rate their health status. Dietary habits can better predict information avoidance than diseases such as food allergy, cardiovascular, cholesterol, or diabetes. Third, women and men are more likely not to avoid information if they find it useful. Risk-seeking, altruism, and positive reciprocity are, roughly speaking, stronger negatively pronounced with men—trust is stronger negatively pronounced with women