Search

Background Double Maddox rod (DMR), the gold-standard method for in-office measurement of cyclodeviation, requires an examiner and specialized equipment. The objective of this study was to develop a virtual reality (VR) technique for measurement of cyclodeviation and validate this against the DMR. Methods A VR-DMR was implemented using a smartphone and commercially available VR viewer. The app displayed a line to each eye and accepted touch inputs from the user to rotate the lines into perceived alignment. VR-DMR cyclodeviation measurements were compared with traditional DMR (T-DMR) cyclodeviation measurements in adults with and without strabismus and children without strabismus. Results Thirty-one subjects were studied (age 5-88 years, 20 with strabismus). VR-DMR had similar test-retest reliability as T-DMR. VR-DMR was highly correlated with T-DMR (r2 = 0.94, linear regression slope 1.12) with a slight positive bias (linear regression y intercept 1°). VR-DMR was preferred by 54% of subjects with 29% having no preference. Conclusions A VR method of ocular cyclodeviation measurement using sensory techniques was implemented using commercially available hardware. VR measurements compared favorably with gold-standard DMR measurements, and user feedback was positive. The VR methodology has application for in office and home use by nonexperts for purposes of strabismus monitoring.

Perceived stress undermines emotional wellbeing, and poorer emotional wellbeing may intensify perceived stress. The current studies examined whether biased memories contribute to the possible reciprocal links between perceived stress and depressive symptoms. Two longitudinal studies compared the stress people perceived for several weeks (Study 1, N = 308) or during a conflict interaction (Study 2, N = 261) with memories of perceived stress gathered in subsequent weeks. People with low depressive symptoms remembered their past as involving less perceived stress than they initially experienced (positive bias). By contrast, people with average or higher levels of depressive symptoms remembered their past as involving exactly as much perceived stress as initially experienced (depressive realism) or, at very high levels of depressive symptoms, more perceived stress than initially experienced (negative bias). These memory biases had important implications. Accounting for initial levels of perceived stress, more negative memories of perceived stress predicted greater weekly depressed mood (Study 1) and greater depressive symptoms across time (Study 2). Evaluating whether life has involved as much perceived stress as now remembered may help facilitate emotional wellbeing in the face of rising perceived stress and depressive symptoms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Older compared to younger adults show greater amygdala activity to positive emotions, and are more likely to interpret emotionally ambiguous stimuli (e.g., surprised faces) as positive. While some evidence suggests this positivity effect results from a relatively slow, top-down mechanism, others suggest it emerges from early, bottom-up processing. The amygdala is a key node in rapid, bottom-up processing and patterns of amygdala activity over time (e.g., habituation) can shed light on the mechanisms underlying the positivity effect. Younger and older adults passively viewed neutral and surprised faces in an MRI. Only in older adults, we found that amygdala habituation was associated with the tendency to interpret surprised faces as positive or negative (valence bias), where a more positive bias was associated with greater habituation. Interestingly, although a positive bias in younger adults was associated with slower reaction times, consistent with an initial negativity hypothesis in younger adults, older adults showed faster ratings of positivity. Together, we propose that there may be a switch to a primacy of positivity in aging.

Intergroup bias — preference for one's in-group relative to out-groups — is one of the most robust phenomena in all of psychology. Here we investigate whether a positive bias that operates at the individual-level, belief in a good true self, may be leveraged to reduce intergroup bias. We find that even stereotypically threatening out-group agents are believed to have a good true self (Experiment 1). More importantly, consideration of an in-group and out-group members' true self reduces intergroup bias, both in the form of explicit evaluative judgments (Experiment 2) and actual donation behavior (Experiment 3). Across studies, the palliative effects of thinking of an individual's true self generalize to that individual's entire group. In sum, a simple intervention — thinking about another's true self — reduces the gap in how people evaluate and treat out-group relative to in-group members. We discuss implications of these findings for conflict reduction strategies.

espanolSe ha analizado estadisticamente la serie secular de precipitacion anual del observatorio Fabra de Barcelona (1914-2020), asi como las de cuatro subperiodos (1914-1930, 1931-1960, 1961-1990, 1991-2020). La serie completa no presenta tendencia estadisticamente significativa, siendo, ademas, parecidos los valores de los parametros estadisticos de los tres subperiodos de 30 anos. Las distribuciones de probabilidad Log-normal y Log-gamma de 2 parametros, con sesgo positivo, ofrecen un buen ajuste tanto de la serie completa, como de las de los tres treintenios, existiendo en cada caso otras varias que tambien lo hacen. La distribucion Normal, aun siendo aceptable segun algunos de los tests de ajuste, es descartada por su simetria y su dominio ilimitado. EnglishThe secular series of annual precipitation from the Fabra observatory in Barcelona (1914-2020) has been statistically analyzed, as well as those from four sub-periods (1914-1930, 1931-1960, 1961-1990, 1991-2020). The complete series does not present a statistically significant trend, and the values of the statistical parameters of the three 30-year sub-periods are similar. The 2-parameter Log-normal and Log-gamma probability distributions, with positive bias, offer a good fit for both the complete series and those of the 30-year series, with several others that also do so in each case. The Normal distribution, even though it is acceptable according to some of the fit tests, is ruled out due to its symmetry and its unlimited domain.

The longest ozone column measurement series are based on the Dobson sun spectrophotometers developed in the 1920s by Gordon B. W. Dobson. These instruments still constitute an important part of the World Meteorological Organization's global network due to their optical qualities and ruggedness. The primary drawback of this instrument is the effort needed for its manual operation. In industrialized and some less developed countries, most stations have made the choice to replace the Dobson by the automated Brewer sun spectrophotometers, but some are still relying on the Dobson instrument. One of them is the Arosa station where both instrument types are run in parallel. Here, an automated version of the Dobson instrument was developed and implemented recently. In the present paper, the results of the analysis of simultaneous measurements from pairs of Dobson instruments that were either collocated at Arosa or Davos or operated one at each location are presented for four distinct time periods: 1992–2012 – manual vs. manual operation of collocated Dobson instruments (MMC); 2012–2013 – manual vs. automated operation of collocated Dobson instruments (MAC); 2012–2019 – automated vs. automated operation of collocated Dobson instruments (AAC); 2016–2019 – automated vs. automated operation of distant Dobson instruments (AAD). The direct comparison of two instruments using the standard operation procedure during the MMC period gives a metric necessary to validate the automated version of Dobson instruments. The direct comparison of two collocated instruments using the standard manual operation procedure reveals random differences of coincident observations with a standard deviation of ∼ 0.45 % and monthly mean differences between −1.0 % and +0.8 %. In most cases the observed biases are not statistically significant. The same analysis of two automated Dobson instruments yields significantly smaller standard deviation of ∼ 0.25 % and biases of between −0.7 % and 0.8 %. This demonstrates that the repeatability has improved with the automation, while the systematic differences are only marginally smaller. The analysis of the AAD period of coincident measurements from the distant sites Arosa and Davos reveals a small positive bias (not significant) compatible with the 250 m altitude difference. The description of the automated data acquisition and control of the Dobson instrument is presented in a separate paper (Stübi et al., 2020).

ObjectiveTo assess the reproducibility of patient-reported tender (TJCs) and swollen joint counts (SJCs) of patients with rheumatoid arthritis (RA) compared to trained clinicians.MethodsWe conducted a systematic literature review and metaanalysis of studies comparing patient-reported TJCs and/or SJCs to clinician counts in patients with RA. We calculated pooled summary estimates for correlation. Agreement was compared using a Bland-Altman approach.ResultsFourteen studies were included in the metaanalysis. There were strong correlations between clinician and patient TJCs (0.78, 95% CI 0.76–0.80), and clinician and patient SJCs (0.59, 95% CI 0.54–0.63). TJCs had good reliability, ranging from 0.51 to 0.85. SJCs had moderate reliability, ranging from 0.28 to 0.77. Agreement for TJCs reduced for higher TJC values, suggesting a positive bias for self-reported TJCs, which was not observed for SJCs.ConclusionOur metaanalysis has identified a strong correlation between patient- and clinician-reported TJCs, and a moderate correlation for SJCs. Patient-reported joint counts may be suitable for use in annual review for patients in remission and in monitoring treatment response for patients with RA. However, they are likely not appropriate for decisions on commencement of biologics. Further research is needed to identify patient groups in which patient-reported joint counts are unsuitable.

Degradations of elevated-metal metal oxide (EMMO) thin-film transistors (TFTs) under positive bias stress (PBS) and positive bias illumination stress (PBIS) are systematically investigated and compared. An intrinsic correlation between PBS and PBIS degradation is demonstrated. Continuous negative threshold voltage ( ${V}_{\text {th}}$ ) shift is observed under both stresses, with similar time-dependent $V_{\text {th}}$ shift and recovery behavior. Characterization parameters for dependencies of ${V}_{\text {th}}$ shift on both stress ${V}_{G}$ and temperature are also very close for the two degradations. PBS and PBIS degradation of EMMO TFTs and their correlation can be consistently understood based on a unified model, which emphasizes stress-induced accumulation of doubly-ionized ${V}_{O}$ traps at the back-channel interface, and is verified with simulation.

SUPER GL compact is a bench-top analyzer for glucose, lactate, and hemoglobin concentrations. Glucose measurements in the biosensor are based on an enzymatic-amperometric reaction of glucose with glucose oxidase. In this study, trueness and precision were assessed with Standard Reference Material 965b (National Institute of Standards and Technology, Gaithersburg, MD) for 2 SUPER GL compact (S1 and S2) and 1 YSI 2300 STAT Plus (Y) device, using a protocol based on CLSI EP05-A3. Precision was similar among S1, S2, and Y. S1 and S2 exhibited negative bias at low concentrations and positive bias at high concentrations, whereas Y showed negative bias that increased with higher concentrations. Overall, SUPER GL compact’s performance was comparable to that of YSI 2300 STAT Plus.

This paper reports on consolidated ground-based validation results of the atmospheric NO2 data produced operationally since April 2018 by the TROPOspheric Monitoring Instrument (TROPOMI) on board of the ESA/EU Copernicus Sentinel-5 Precursor (S5P) satellite. Tropospheric, stratospheric, and total NO2 column data from S5P are compared to correlative measurements collected from, respectively, 19 Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS), 26 Network for the Detection of Atmospheric Composition Change (NDACC) Zenith-Scattered-Light DOAS (ZSL-DOAS), and 25 Pandonia Global Network (PGN)/Pandora instruments distributed globally. The validation methodology gives special care to minimizing mismatch errors due to imperfect spatio-temporal co-location of the satellite and correlative data, e.g. by using tailored observation operators to account for differences in smoothing and in sampling of atmospheric structures and variability and photochemical modelling to reduce diurnal cycle effects. Compared to the ground-based measurements, S5P data show, on average, (i) a negative bias for the tropospheric column data, of typically −23 % to −37 % in clean to slightly polluted conditions but reaching values as high as −51 % over highly polluted areas; (ii) a slight negative median difference for the stratospheric column data, of about −0.2 Pmolec cm−2, i.e. approx. −2 % in summer to −15 % in winter; and (iii) a bias ranging from zero to −50 % for the total column data, found to depend on the amplitude of the total NO2 column, with small to slightly positive bias values for columns below 6 Pmolec cm−2 and negative values above. The dispersion between S5P and correlative measurements contains mostly random components, which remain within mission requirements for the stratospheric column data (0.5 Pmolec cm−2) but exceed those for the tropospheric column data (0.7 Pmolec cm−2). While a part of the biases and dispersion may be due to representativeness differences such as different area averaging and measurement times, it is known that errors in the S5P tropospheric columns exist due to shortcomings in the (horizontally coarse) a priori profile representation in the TM5-MP chemical transport model used in the S5P retrieval and, to a lesser extent, to the treatment of cloud effects and aerosols. Although considerable differences (up to 2 Pmolec cm−2 and more) are observed at single ground-pixel level, the near-real-time (NRTI) and offline (OFFL) versions of the S5P NO2 operational data processor provide similar NO2 column values and validation results when globally averaged, with the NRTI values being on average 0.79 % larger than the OFFL values.

Despite much interest in how parenthood contributes to the gender pay gap, prior research has rarely explored firms' roles in shaping the parenthood pay penalty or premium. The handful of studies that investigated parenthood's effects within and across firms generally compared parents and their childless peers at a given time and failed to account for unobserved heterogeneity between the two groups. Such comparisons also cannot inform how having children may alter individuals' earnings trajectories within and across firms. Using 26 rounds of the National Longitudinal Survey of Youth 1979 and fixed-effects models, we examine how being a mother or father is linked to earnings growth within and across firms. We find that women's pay decreases as they become mothers and that the across-employer motherhood penalty is larger than the within-employer penalty. By contrast, fatherhood is associated with a pay premium, and the within-employer fatherhood premium is considerably greater than the across-employer one. We argue that these results are consistent with the discrimination explanation of the motherhood penalty and fatherhood premium. Because employers are likely to trust women who become mothers while working for them more than new recruits who are mothers, their negative bias against mothers would be more salient when evaluating the latter, which could result in a larger between-organizational motherhood penalty. Conversely, employers' likely greater trust in existing workers who become fathers than fathers they hire from elsewhere may amplify their positive bias favoring fathers in assessing the former, which could explain the greater within-firm fatherhood premium.

To improve the turn-off speed and uniformity of atomic threshold switching (TS) devices, we propose the use of the AgSe electrode and controlled bipolar pulse forming method. Compared with TS devices with Ag and AgTe electrodes, TS device with the AgSe electrode shows an extremely fast turn-off speed, which can be explained by the limited injection of Ag into the switching layer. By applying positive bias (Icc = 500 nA, 1 ms) followed by negative bias (−0.1 to −0.2 V, $10~\mu \text{s}$ ), the TS device exhibits excellent switching uniformity. It can be explained by the formation of atomic-scale filament under the positive bias at low Icc and drift-back of excessive Ag by the negative bias. By designing the shape of the filament and concentration of the residual Ag, the TS device with the AgSe electrode shows promise for selector applications.

Background Thyroid-stimulating hormone receptor (TSHR)-activating autoantibodies stimulate thyroid growth and hormone synthesis/secretion, causing hyperthyroidism of Graves’ disease (GD). TRAb measurement helps diagnose GD and is an important first test in evaluating hyperthyroidism according to the recent American Thyroid Association guidelines. We compared the performance of the BRAHMS TRAK Kryptor (Thermo Scientific) and Roche cobas TRAb immunoassays for use in GD. Method Method comparison (n = 40) and clinical agreement were assessed between the Kryptor, cobas e411, and cobas e601. The analytical performance of Kryptor and cobas e411 were assessed for within- and between-day imprecision across 20 days, linearity, functional assay sensitivity (FAS), dilution recovery, and cut-off verification. Results The Kryptor, e411, and e601 TRAb immunoassays correlated well (r > 0.95, overall percent agreement = 0.95, Cohen’s kappa = 0.90). With a total allowable error of 20%, percent bias was within 13%, which was minimally negative at 20 IU/L. The Kryptor, but not e411, was linear across the claimed analytical measuring range (AMR). The claimed functional assay sensitivity (FAS), which was close to the clinical GD cut-off 1.8 IU/L, was verified for Kryptor and e411. Conclusion Overall, our evaluation demonstrates acceptable comparability between TRAb immunoassays with in-house imprecision up to 13% and 10% on Kryptor and e411, respectively. While Roche has preferable calibration frequency and on-board reagent stability, both platforms demonstrate acceptable imprecision using patient samples at their claimed FAS, which is important for GD diagnosis. Diluted results (using a negative patient pool as diluent) exhibits proportional positive bias on the Kryptor relative to the Roche methods.

Introduction: Effective diagnosis of cardiovascular diseases requires the right tools to be used enabling selective and sensitive analysis of their biomarkers. One of them is homocysteine (Hcy), nowadays determined by immunoassays and chromatographic methods. This study aims to compare the results obtained by direct chemiluminescence immunoassay (CLIA) and high performance liquid chromatography with fluorescent detection (HPLC-FD) using commercial kits. Materials and methods: Homocysteine concentration was determined in serum samples obtained from 101 individuals, using Atellica IM HCY (Siemens Healthineers, Erlangen, Germany) and HCY in plasma/serum – HPLC-FD (Chromsystems Instruments & Chemicals GmbH, Gräfelfing, Germany) tests validated for routine analysis. The latter was applied as a reference method. The comparability and agreement between the tested methods were evaluated using the Passing-Bablok (PB) regression analysis and the Bland-Altman (BA) method of the differences analysis. Results: Studies showed that CLIA gives higher Hcy concentrations (15.7 ± 4.14 μmol/L). Passing-Bablok regression analysis of the results obtained with CLIA (y) compared with HPLC-FD (x) yielded an intercept of 0.22 (95%CI: - 2.16 to 2.46) and slope of 1.58 (95%CI: 1.33 to 1.87). Bland-Altman analysis demonstrated a systematic positive bias for CLIA of 5.85 ± 2.77 μmol/L. Conclusions: Methods disagreement precludes their interchangeability. Lower Hcy values by HPLC-FD result from its greater selectivity. High performance liquid chromatography with fluorescent detection should be considered as preferential method for analysing Hcy in blood serum as well as the recommended reference method for routine clinical analysis. This fact, however, imposes the need to establish new reference ranges.

Promotion in science has attracted increasing attention in recent years, and various linguistic devices such as boosters, hypes, or positive words were used to promote research for publication purposes. The present study examined how researchers promote their work with linguistic devices such as positive and negative words and is probably the first one that investigates such promotional devices in not only abstracts but also full texts based on a large dataset of articles (more than 2.2 million). The results showed that the use of positive words in both the abstracts and full texts exhibited a significant uptrend in the past two decades, and positive words were more frequently used than negative ones in both abstracts and full texts. However, journal impact was found to be only very weakly correlated with the use of positive and negative words in both abstracts and full texts. The preference of promotional linguistic devices such as positive words may be explained by factors such as the increasingly competitive selection process of publication, the publication bias, the outcome reporting bias, and the universal positive bias. The study argues for a fair use of such promotional linguistic devices.

International guidelines recommend salivary cortisol for the diagnosis of Cushing’s syndrome. Despite mass spectrometry-based assays are considered the analytical gold-standard, there is still the need to define reference intervals and diagnostic accuracy of such methodology. 100 healthy volunteers and 50 consecutive patients were enrolled to compare LC–MS/MS and electrochemiluminescence assay for the determination of late-night salivary cortisol and cortisone. Moreover, we aimed to determine reference intervals of salivary steroids in a population of healthy individuals and diagnostic accuracy in patients with suspected hypercortisolism and in a population including also healthy individuals. Method comparison highlighted a positive bias (51.8%) of immunoassay over LC–MS/MS. Reference intervals of salivary cortisol (0.17–0.97 µg/L), cortisone (0.84–4.85 µg/L) and ratio (0.08–0.30) were obtained. The most accurate thresholds of salivary cortisol for the diagnosis of hypercortisolism were 1.15 µg/L in the population with suspected hypercortisolism (AUC 1) and 1.30 µg/L in the population including also healthy individuals (AUC 1). Cut-off values of salivary cortisone (7.23 µg/L; Se 92.9%, Sp 97.2%, AUC 0.960 and Se 92.9%, Sp 99.1%, AUC 0.985 in suspected hypercortisolism and in overall population, respectively) and cortisol-to-cortisone ratio (0.20; Se 85.7%, Sp 80.6%, AUC 0.820 and Se 85.7%, Sp 85.5%, AUC 0.855 in suspected hypercortisolism and in overall population, respectively) were accurate and similar in both populations. LC–MS/MS is the most accurate analytical platform for measuring salivary steroids. Obtained reference intervals are coherent with previously published data and diagnostic accuracy for diagnosis of overt hypercortisolism proved highly satisfactory.

The angel investing space has transformed as investors have moved from individual deal seeking to more collaborative models of investing. Angel networks are formal investor organizations that pursue investment deals with entrepreneurs, assist with deal screening, and coordinate due diligence. These coordination activities have clear benefits for angel network members, but they also give rise to a dynamic of reliant judgment in which the espoused opinions of network peers are taken as evidence that weighs heavily on the investment decision. In this article, we provide evidence from an experiment set in an angel investment pitch meeting that reveals the positive bias an angel investor shows toward peer opinions. By revealing these potentially hidden forces in angel network deliberations, we raise awareness and, by extension, offer response strategies for angels and angel network directors to properly manage the influence of peer opinion in angel network discussions.

Satellite-based precipitation data can be a valuable source for performing hydro-climatological analyses: such as drought and water balance estimations with long and temporally consistent data. In this study, the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) precipitation estimations were compared with station-based precipitation measurements at daily, dekadal, and monthly time scales using statistical and categorical validation measures. The assessment study includes 77 ground-based meteorological stations distributed throughout Turkey, and the study period corresponds to years 2008 through 2018. Overall evaluation indicates that CHIRPS estimates exhibit high correlation on dekadal and monthly time scales; however correlation decreases for daily estimates. A positive bias is found over Turkey, and a particular overestimation was detected between the precipitation amounts of 0–25 mm/dekad and 0–80 mm/month. CHIRPS tends to underestimate high precipitation amounts of 25–80 mm/dekad and 150–300 mm/month. CHIRPS estimations show the best performance in winter when Turkey’s precipitation regime is dominated by cyclones and the lowest performance in the spring season. The study area was delineated into six regions according to their precipitation climatology and hydrological basins borders. The best performance for monthly CHIRPS estimates was in western Anatolia (r = 0.88). For all regions, precipitation detection capability is significantly high not only for monthly but also for dekadal CHIRPS estimates. Probability of detection was found between 0.83 and 0.98, and the false alarm rate changes between 0.30 and 0.13 for the thresholds of 50 mm/month and 5 mm/month, respectively. In rainfall categories of 30, 40, and 50 mm / month the capacity to determine rain and no rain was significantly high. CHIRPS estimations for 54 meteorological stations were reasonably biased (between ± 20%) with ground-based observations. Results show that CHIRPS estimations over Western Anatolia, Southern Anatolia, and Marmara regions are more consistent than the mountainous eastern and northeastern parts of the country. CHIRPS estimates can be used for hydro-climatological studies such as drought and water balance modeling over Turkey considering the error characteristics presented in this study.

The purpose of this study is to determine guest misreport sources in Airbnb reviews. Previous studies have signalled the existence of positive bias in reviews. Here we examine the relationship betw...

BACKGROUND Stack-of-radial multiecho gradient-echo MRI is promising for free-breathing liver R2* quantification and may benefit children. PURPOSE To validate stack-of-radial MRI with self-gating motion compensation in phantoms, and to evaluate it in children. STUDY TYPE Prospective. PHANTOMS Four vials with different R2* driven by a motion stage. SUBJECTS Sixteen pediatric patients with suspected nonalcoholic fatty liver disease or steatohepatitis (five females, 13 ± 4 years, body mass index 29.2 ± 8.6 kg/m2 ). FIELD STRENGTH/SEQUENCES Stack-of-radial, and 2D and 3D Cartesian multiecho gradient-echo sequences at 3T. ASSESSMENT Ungated and gated stack-of-radial proton density fat fraction (PDFF) and R2* maps were reconstructed without and with self-gating motion compensation. Stack-of-radial R2* measurements of phantoms without and with motion were validated against reference 2D Cartesian results of phantoms without motion. In subjects, free-breathing stack-of-radial and reference breath-hold 3D Cartesian were acquired. Subject inclusion for statistical analysis and region of interest placement were determined independently by two observers. STATISTICAL TESTS Phantom results were fitted with a weighted linear model. Demographic differences between excluded and included subjects were tested by multivariate analysis of variance. PDFF and R2* measurements were compared using Bland-Altman analysis. Interobserver agreement was assessed by the intraclass correlation coefficient (ICC). RESULTS Ungated stack-of-radial R2* inside moving phantom vials showed a significant positive bias of 64.3 s-1 (P 0.31). Subject inclusion decisions for statistical analysis from two observers were consistent. No significant differences were found between four excluded and 12 included subjects (P = 0.14). Compared to breath-hold Cartesian, ungated and gated free-breathing stack-of-radial exhibited mean R2* differences of 18.5 s-1 and 3.6 s-1 . Mean PDFF differences were 1.1% and 1.0% for ungated and gated measurements, respectively. Interobserver agreement was excellent (ICC for PDFF = 0.99, ICC for R2* = 0.90; P

Given the positive bias toward attractive people in society, online sellers are justifiably apprehensive about perceptions of their profile pictures. Although the existing literature emphasizes the “beauty premium” and the “ugliness penalty,” the current studies of seller profile pictures on customer-to-customer e-commerce platforms find a U-shaped relationship between facial attractiveness and product sales (i.e., both beauty and ugliness premiums and, thus, a “plainness penalty”). By analyzing two large data sets, the authors find that both attractive and unattractive people sell significantly more than plain-looking people. Two online experiments reveal that attractive sellers enjoy greater source credibility due to perceived sociability and competence, whereas unattractive sellers are considered more believable on the basis of their perceived competence. While a beauty premium is apparent for appearance-relevant products, an ugliness premium is more pronounced for expertise-relevant products and for female consumers evaluating male sellers. These findings highlight the influence of facial appearance as a key vehicle for impression formation in online platforms and its complex effects in e-commerce and marketing.