Chronometric Analysis Research Articles

Temporal demands of elite fencing.

There is no published study that analyses the temporal demands of fencing, in its six Olympic modalities in the same high-level competition. The only existing publications date back decades, with already obsolete regulations, or focus on a specific modality. The aim of this study is to carry out a chronometric analysis of elite fencing at the 2014 Fencing World Championships to determine the existence of differences between its weapons (épée, foil and sabre) and between genders. A total of 96 elite fencers (48 women) of 24 different nationalities were analysed in the final rounds (direct elimination). We undertook observational methodology based on an open and systematic process with ideographic, point and multi-dimensional design. We analysed the work time, rest time, total time, number of stops and work-to-rest ratio. The Lince software was used to record and analyse video data. The coding and recording process of the 83 fights analysed generated a matrix of 5900 records. The quality of the data was verified by checking the validity of the observation instrument and the intraobserver reliability. The mean work time (between Allez and Halte) was 17.9 ± 3.1 s for épée, 5.8 ± 2.5 s for foil and 1 .7 ± 0.4 s for sabre. The fight work-to-rest ratios recorded were 1:0.9, 1:2.6 and 1:9.2 for épée, foil and sabre respectively. The results showed significant differences (p < .05) in the work and rest times between the three fencing weapons. However, there were no differences between fencers of the same weapon according to gender.

Using Weibull model of survival analysis workflow and its relevant factors: A prospective cohort study

Objective: One of the most important indicators used in the evaluation of emergency centers is the chronometric analysis of patients’ workflow. The aim of this study was to provide a chronometric analysis of patients’ workflow (patients’ waiting time in the emergency department) and related factors. Methods: This hospital-based prospective cohort study was carried out in Khatam al-Anbia hospital in Shoushtar in 2020. Random sampling was used and patients referred to the emergency ward in three shifts based on the ESI 5-level triage system. The research tools were the emergency workflow chronometry form and a questionnaire of determining the factors related to the speed of emergency services and using a stopwatch. In order to analyse the data, Stata software version 16 and Weibull model of survival analysis were used. Results: Of 468 participants, the most common cause of referral was trauma with 21.7%. The median±interquartile range duration of giving the final result was 6.06±4.48 hours, which was more than 0.54 times shorter in clients with level 3. There was a statistically significant difference in the duration of making the final decision based on the request for testing, manner of referring and the type of initial diagnosis (P&lt;0.05). Conclusion: The duration of service provision in the studied hospital is appropriate for an Iranian hospital, but it should be closer to international standards. At level 2 triage, patients stayed longer. This can be reduced by lessening the time of consultations which can help the emergency ward.

Hitting movement patterns organized by different pitching movement speeds as advanced kinematic information.

Conventionally, hitting movements in response to different advanced kinematic information have been investigated from the perspective of chronometric analysis, such as measuring the timing of movements. This is the first study to investigate the effect of manipulating advanced kinematic information on the hitting movement pattern organization based on both kinematics and kinetic analyses in addition to the conventional chronometric analysis. Specifically, the hitting movement of experienced batters in response to visual stimuli consisting of different pitching movement speeds with the same ball trajectory information was measured by an optical motion capture camera system and a foot force sensor inside the shoes. The occurrence timings of specific events (e.g., movement initiation), some kinematic parameters (e.g., maximum rotate angle of the shoulder and hip), and the balance of the ground reaction force between the ball of the big and small toes of both feet were compared between experimental conditions. This was done to test the hypothesis that the hitting movement is coupled with the visual information given to batters based on an expert anticipatory model. The results indicated that for a faster pitching speed, the batter tended to react with a significantly smaller preparatory movement (e.g., smaller weight shift and shoulder rotate angle during backswing) and put significantly larger weight on the rear foot during the swing execution phase. The situation was exactly reverse in the case of a slower pitching movement. These results suggest for the first time that manipulating advanced kinematic information not only affects the timing of the movement, but also the whole-body kinematics and lower body kinetics. The results also indicate that the hitting movement pattern of experienced batters is highly dependent on the advanced kinematic information.

ACCURACY OF EXPERT FRAUD DETECTION TECHNOLOGY IN REMOTE TEST EXAMS (PROCTORING)

The purpose (objective) of the empirical study is the measurement of the accuracy of expert-proctors in detecting cheating in online testing. Sample of the study. 35 test takers passed an online test of general knowledge on the basis of 30 multiple choice questions. Half of the subjects (18 persons) were “artificial cheaters” — they used cheat sheets with correct answers. Methods. The video recording of the testing process included a “screen capture” so that expert-proctors could observe all cursor movements, see a recording of the subject’s facial expressions and a visual focus of attention in a separate window (recording from the front camera), and could listen to the subject pronouncing the task conditions and answers (“oral decision”). 14 experts took part in rating of video recordings, of which 8 experts showed satisfactory results in terms of the level of accuracy in detecting cheating (their accuracy that was measured using the Kappa coefficient was higher than 0.5). Conclusions. A high asymmetric validity of expert assessments is revealed. More accurate experts allowed a negligible (about 5 percent) number of errors of the “false alarm” type, but a relatively large number of errors of the “skip” type. Recommendations are made for the practical use of the expert assessment method in combination with automatic chronometric analysis of the degree of atypical protocols and subsequent control of face-to-face offline testing of all suspected subjects (examinees).

The Analysis of Working Load of General Practitioners in the Republic of Kazakhstan

The article provides results of a chronometric analysis of patients a polyclinic in Kazakhstan, as well as of and analysis and study of the working hours spent by doctors for accomplishment of various labor transactions. The statistical analysis defined the basic factors influencing the duration of reception of patients by general practitioners (GP) doctors. They are: the communicative factor, operating procedures, and document processing. The basic factors influencing the duration of patient reception by GP doctors are the communicative factor or Component 1 (r=0.805), operational procedures or Component 2 (r=0.736), and documentation processing or Component 3 (r=0.528). The forecast of data reception time (by GP doctors), depending on the availability of technical work, the documentation showed us that generally three factors (technical work, internal documentation, and additional procedures) have a very significant effect on the dependent variable (patient reception). It turns out that the time spent for additional inspection of patients, contributes to a more rapid and faithful inspection of results and reduced the patient reception time, on the other hand the presence of technical work and documentation processing helps increase the time of reception be a GP doctor.

How is the serial order of a visual sequence represented? Insights from transposition latencies.

A central goal of research on short-term memory (STM) over the past 2 decades has been to identify the mechanisms that underpin the representation of serial order, and to establish whether these mechanisms are the same across different modalities and domains (e.g., verbal, visual, spatial). A fruitful approach to addressing this question has involved comparing the transposition error latency predictions of models built from different candidate mechanisms for representing serial order. Experiments involving the output-timed serial recall of sequences of verbal (Farrell & Lewandowsky, 2004) and spatial (Hurlstone & Hitch, 2015) items have revealed an error latency profile consistent with the prediction of a competitive queuing mechanism within which serial order is represented via a primacy gradient of activations over items, associations between items and position markers, with suppression of items following recall. In this paper, we extend this chronometric analysis of recall errors to the serial recall of sequences of visual, nonspatial, items and find across 3 experiments an error latency profile broadly consistent with the prediction of the same representational mechanism. The findings suggest that common mechanisms and principles contribute to the representation of serial order across the verbal, visual, and spatial STM domains. The implications of these findings for theories of short-term and working memory are considered. (PsycINFO Database Record

CALCINED BONE AS A RELIABLE MEDIUM FOR RADIOCARBON DATING: A TEST USING PAIRED NORTH AMERICAN SAMPLES

Radiocarbon dating using charcoal and bone collagen, two standards of archaeological chronology, can be difficult to impossible in environments where natural burning is common and bone does not preserve well. In such settings, charcoal ages cannot always be trusted and collagen is unavailable. Calcined bone can be a viable alternative medium in these situations but it has rarely been exploited in the Americas. One area that could benefit from its use is the forested Pacific Northwest. We compare calcined bone ages with charcoal and/or collagen dates from individual features or discrete cultural strata in 10 Washington, Oregon, Idaho, and British Columbia sites dating between 9000 and 100 B.P. Resulting radiocarbon age estimates based on calcined bone closely match those based on charcoal and/or collagen in nearly all cases. We obtained calcined bone dates from three additional Holocene-aged sites that had not previously produced accurate results, obtaining findings consistent with estimates based on cross dating. Preserving well where all other organic media of cultural origin are lost or unreliable, calcined bone holds promise for dating sites in conifer forests and other acidic soil settings, and can allow researchers to refine archaeological sequences that have long defied accurate chronometric analysis.

A Critical Approach to 14C Dating in the Caribbean: Using Chronometric Hygiene to Evaluate Chronological Control and Prehistoric Settlement

Radiocarbon (14C) dating is one of the most important tools for archaeologists. Although radiocarbon dates provide a temporal foundation for analyzing the remains of past cultures, it is critical that these dates be periodically reviewed for consistency and accuracy to ensure chronological control. A review of publications pertaining to Caribbean archaeology since the 1960s demonstrates that researchers there have often failed to adequately report and critique radiocarbon dates, making it difficult to fully assess their value in chronology building. A chronometric hygiene analysis of over 600 dates reveals that when isolated, culturally ambiguous, poorly provenienced, and contaminated dates are rejected, only about 80 percent remain useful. In addition, the paucity of early Saladoid (ca. 500 B.C.–A.D. 1) and Archaic age (ca. 2500–500 B.C.) dates in the southern Lesser Antilles suggests that there was not a “stepping-stone” migration of prehistoric peoples northward from South America into the Lesser Antilles.

Selection of methods used for analyzing the standard time needed to complete the assembly process by means of a fuzzy analytic hierarchy process

This paper is a review of four main methods of analyzing the standard time needed to complete a given job: chronometric analysis, working-day activity study (working-day photo), work sampling observations, and analysis of basic motions. Thanks to the application of FAHP (Fuzzy Analytic Hierarchy Process) method, the values of weighted coefficients were obtained which describe the importance of selecting the criteria of the choice of methods used to analyze the standard time in the assembly process. In the summary paragraph of this paper, the results of analyzing the criteria are discussed.

Moche Sociopolitical Dynamics and the Role of Licapa II, Chicama Valley, Peru

Fieldwork at the Moche (A .D. 250–900) site of Licapa II in the Chicama Valley, Peru, has resulted in a more nuanced history of the changing sociopolitical relationships among Moche centers. The distinct archaeological signatures of Moche society, namely ceramics and huacas (monumental structures), have been interpreted as emblematic of an ethnic and political reality and as evidence for a state. Nonetheless, scholars are now disentangling these assumptions, arguing that Moche society was a complex mosaic of interacting settlements. My research at Licapa II combined surface collection, geophysical surveys, excavation, and chronometric analysis to better understand this site within the context of broader Moche sociopolitical dynamics. Ceramic and architectural evidence from Licapa II indicates that a shift in ideological organization occurred around A.D. 650. This shift reflects changes seen throughout the Moche world. Licapa II is located on the border of the northern and southern regions of Moche cultural development, and ceramic styles indicate that many of the interactions between these regions could have occurred here. By comparing these findings to evidence of sociopolitical reorganization seen elsewhere, research from Licapa II contributes to a non-state and decentralized view of the sociopolitical structure of Moche society.

Individual differences in highly skilled visual perceptual-motor striking skill.

Expertise studies into visual perceptual-motor skills have mainly focused their investigation upon group comparisons rather than individual comparisons. This study investigated the pick-up of visual information to time weight transfer and bat kinematics within an exemplar group of striking sport experts using an in situ temporal occlusion paradigm. Highly skilled cricket batsmen faced bowlers and attempted to strike delivered balls, whilst their vision was either temporally occluded through occlusion glasses prior to ball bounce or not occluded (control condition). A chronometric analysis was conducted on trials in the occlusion condition to quantify the pick-up of visual information to time biomechanical variables. Results indicated that initiation of weight transfer and bat downswing, as well as bat downswing completion, was significantly different between some individual batsmen. No significant difference was found between individual batsmen for time of weight transfer completion. Unexpectedly, it was found that achievement of the goal to strike delivered balls, that is, the frequency of bat-ball contacts was not significantly different between batsmen. Collectively, the findings indicate that individual differences exist in the coordination pattern of a complex whole body visual perceptual-motor skill, but these different patterns are used to achieve a similar outcome, which is known as motor equivalence.

Neural chronometry and coherency across speed–accuracy demands reveal lack of homomorphism between computational and neural mechanisms of evidence accumulation

The stochastic accumulation framework provides a mechanistic, quantitative account of perceptual decision-making and how task performance changes with experimental manipulations. Importantly, it provides an elegant account of the speed-accuracy trade-off (SAT), which has long been the litmus test for decision models, and also mimics the activity of single neurons in several key respects. Recently, we developed a paradigm whereby macaque monkeys trade speed for accuracy on cue during visual search task. Single-unit activity in frontal eye field (FEF) was not homomorphic with the architecture of models, demonstrating that stochastic accumulators are an incomplete description of neural activity under SAT. This paper summarizes and extends this work, further demonstrating that the SAT leads to extensive, widespread changes in brain activity never before predicted. We will begin by reviewing our recently published work that establishes how spiking activity in FEF accomplishes SAT. Next, we provide two important extensions of this work. First, we report a new chronometric analysis suggesting that increases in perceptual gain with speed stress are evident in FEF synaptic input, implicating afferent sensory-processing sources. Second, we report a new analysis demonstrating selective influence of SAT on frequency coupling between FEF neurons and local field potentials. None of these observations correspond to the mechanics of current accumulator models.

The Persistence of Mode 1 Technology in the Korean Late Paleolithic

Ssangjungri (SJ), an open-air site with several Paleolithic horizons, was recently discovered in South Korea. Most of the identified artifacts are simple core and flake tools that indicate an expedient knapping strategy. Bifacially worked core tools, which might be considered non-classic bifaces, also have been found. The prolific horizons at the site were dated by accelerator mass spectrometry (AMS) to about 30 kya. Another newly discovered Paleolithic open-air site, Jeungsan (JS), shows a homogeneous lithic pattern during this period. The dominated artifact types and usage of raw materials are similar in character to those from SJ, although JS yielded a larger number of simple core and flake tools with non-classic bifaces. Chronometric analysis by AMS and optically stimulated luminescence (OSL) indicate that the prime stratigraphic levels at JS also date to approximately 30 kya, and the numerous conjoining pieces indicate that the layers were not seriously affected by post-depositional processes. Thus, it can be confirmed that simple core and flake tools were produced at temporally and culturally independent sites until after 30 kya, supporting the hypothesis of a wide and persistent use of simple technology into the Late Pleistocene.

Are tetraplegic handbikers going to disappear from team relay in para-cycling?

Are tetraplegic handbikers going to disappear from team relay in para-cycling?

On the ability to directly evaluate sensory ratios

The study explored whether participants could directly evaluate sensory ratios. The results indicate that they did not exhibit this ability for the extensive continuum of length and the intensive continua of brightness and brightness difference. Functional measurement analysis, combined with a chronometric analysis of responses, indicated that participants used mental counting for length and used difference evaluation for brightness and brightness difference. The finding that participants evaluated brightness differences under instructions to evaluate brightness ratios suggests that difference judgments may be a general human capability. It resolves questions raised by prior tests of Torgerson's conjecture and by prior consistency tests of ratio evaluation.

Milankovitch-Scale Sequence Stratigraphy and Stepped Forced Regressions of the Turonian Ferron Notom Deltaic Complex, South-Central Utah, U.S.A

Abstract Laterally extensive outcrops in south-central Utah of the Turonian Ferron Notom Delta Complex and its bounding shales contain numerous chronometrically age-dated bentonite beds. The chronometry enables estimation of rates of accommodation and accumulation change. Integration of 56 measured sections and walking and tracing of beds allowed rigorous application of the concept of shoreline trajectory, using the lower bentonites as stratigraphic datums. Geometric stratal relationships along with facies dislocations were used to define high-frequency sequences and systems tracts. Forty-three parasequences were grouped into 18 parasequence sets, five simple sequences, and one sequence set. Parasequence sets show repeated, aggradational–progradational, degradational, progradational–aggradational, and retrogradational stacking patterns, which match the recently developed accommodation succession model. The chronometric analysis shows that the high-frequency sequences are Milankovitch-scale (approximately 100,000 yr), and record sea-level falls of up to 50 meters. The most complete sequence set, sequence set 3, shows clear evidence of a prolonged and stepped forced regression, with two additional higher-frequency sequences (possibly 40 kyr cycles), forming a forced regressive sequence set. This matches previous observations that valley systems, associated with the sequence boundaries, are compound, and also record higher-frequency cut-and-fill cycles. Among the various controlling factors causing cyclicity, such as shoreline autoretreat, delta-lobe switching, and allogenic controls such as climate, tectonics, and eustasy, we hypothesize that glacio-eustasy is the most likely control on the cyclicity of Ferron deposition, overprinted on a tectonically active basin. Gradual build-up of glaciers are hypothesized as a possible explanation of the punctuated downsteps observed in the forced regressive sequence set 3.

Online control of reaching is impaired in adults with developmental coordination disorder- DCD

Event Abstract Back to Event Online control of reaching is impaired in adults with developmental coordination disorder- DCD Ian Fuelscher1, Reannon Ivancic2, Chevelle Smalley2, Emra Oguzkaya2, Jacqueline Williams3 and Christian Hyde1* 1 Deakin University, School of Psychology, Australia 2 Victoria University, School of Social Sciences and Psychology, Australia 3 Victoria University, Institute of Sport, Exercise and Active Living and School of Sport and Exercise Science, Australia Developmental Coordination Disorder (DCD) is a serious disorder of movement that presents in the absence of identifiable neurological or intellectual deficit. Once considered transitory, there is compelling evidence that without targeted intervention, poor motor skill often persists into adulthood. Though the cause/s of the disorder continue to be debated, we recently demonstrated that children with DCD show a specific deficit in making fast corrections to movement following target displacement (viz online control: Hyde & Wilson, 2011a,b). This suggests possible immaturity at the level of the predictive modelling systems considered critical to online control. However, it is unclear how on-line control (and hence predictive modelling) may be affected in individuals whose motor difficulties persist into adulthood. Accordingly, we compared 7 young adults (aged 19- 25 years) with and without DCD on the double-step reaching task. Participants were required to reach and touch one of three possible targets. For most trials (80%) the target remained stationary throughout movement (non-jump trials), while for the remaining trials (20%) the target jumped to one of two peripheral locations at movement onset (jump-trials). As predicted, adults with DCD showed a reduced capacity for making fast online corrections to reaching shown by overall slower jump trial performance (yet relatively preserved non-jump reaching) and slower reaching trajectory correction: this pattern of results suggests difficulties using predictive estimates of limb position to control reaching. Further, it extends earlier work on children with DCD, suggesting that online control (and therefore predictive modelling) continues to be compromised beyond childhood. References Hyde, C., & Wilson, P. H. (2011a). Dissecting online control in Developmental Coordination Disorder: A kinematic analysis of double-step reaching. Brain and Cognition, 75, 232-241. Hyde, C., & Wilson, P. H. (2011b). Online control in children with Developmental Coordination Disorder: Chronometric analysis of double-step reaching performance. Child: Care, Health and Development, 37, 111-122. Keywords: developmental coordination disorder, double-step reaching task, online control, Predictive Modeling, Developmental Cognitive Neuroscience Conference: ACNS-2012 Australasian Cognitive Neuroscience Conference, Brisbane, Australia, 29 Nov - 2 Dec, 2012. Presentation Type: Oral Presentation Topic: Motor Citation: Fuelscher I, Ivancic R, Smalley C, Oguzkaya E, Williams J and Hyde C (2012). Online control of reaching is impaired in adults with developmental coordination disorder- DCD. Conference Abstract: ACNS-2012 Australasian Cognitive Neuroscience Conference. doi: 10.3389/conf.fnhum.2012.208.00038 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Oct 2012; Published Online: 07 Nov 2012. * Correspondence: Dr. Christian Hyde, Deakin University, School of Psychology, Melbourne, Victoria, 3125, Australia, c.hyde@deakin.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Ian Fuelscher Reannon Ivancic Chevelle Smalley Emra Oguzkaya Jacqueline Williams Christian Hyde Google Ian Fuelscher Reannon Ivancic Chevelle Smalley Emra Oguzkaya Jacqueline Williams Christian Hyde Google Scholar Ian Fuelscher Reannon Ivancic Chevelle Smalley Emra Oguzkaya Jacqueline Williams Christian Hyde PubMed Ian Fuelscher Reannon Ivancic Chevelle Smalley Emra Oguzkaya Jacqueline Williams Christian Hyde Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Online motor control in children with developmental coordination disorder: chronometric analysis of double-step reaching performance

Although there are a number of plausible accounts to explain movement clumsiness in children [or developmental coordination disorder (DCD)], the cause(s) of the disorder remain(s) an issue of debate. One aspect of motor control that is particularly important to the fluid expression of skill is rapid online control (ROC). Data on DCD have been conflicting. While some recent work using double-step reaching suggests no difficulty in online control, others suggest deficits (e.g. based on sequential pointing). To help resolve this debate, we suggest two things: use of recent neuro-computational models as a framework for investigating motor control in DCD, and more rigorous investigation of double-step reaching. Our working assumption here is that ROC is only viable through the seamless integration of predictive (or forward) models of movement and feedback-based mechanisms. The aim of this chronometric study was to explore ROC in children with DCD using a double-step reaching paradigm. We predicted slower online adjustments in DCD based on the argument that these children manifest a core difficulty in predictive control. Participants were a group of 17 children with DCD and 27 typically developing children aged between 7 and 12 years. Visual targets were presented on a 17-inch LCD touch screen, inclined to an angle of 15° from horizontal. The children were instructed to press each target as it appeared as quickly and accurately as possible. For 80% of the trials, the central target location remained unchanged for the duration of the movement (non-jump trials), while for the remaining 20% of trials, the target jumped at movement onset to one of the two peripheral locations (jump trials). Reaction time (RT), movement time (MT) and reaching errors were recorded. For both groups, RT did not vary according to trial condition, while children with DCD were slower to initiate movement. Further, the MT of children with DCD was prolonged to a far greater extent on jump trials relative to controls, with a large effect size. As well, children with DCD committed significantly more errors, notably a reduced ability to inhibit central responses on jump trials. Our findings help reconcile some disparate findings in the literature using similar tasks. The pattern of performance in children with DCD suggests impairment in the ability to make rapid online adjustments that are based on a predictive (or internal) model of the action. These results pave the way for future kinematic investigation.

Molecular Phylogenetics and Chronometrics of Tarsiidae Based on 12S mtDNA Haplotypes: Evidence for Miocene Origins of Crown Tarsiers and Numerous Species within the Sulawesian Clade

We report new mitochondrial DNA sequence data from tarsiers sampled from several populations, including the extreme northeast and southwest of the range of the Tarsius tarsier species complex, the most extensive sampling ever reported for this taxon. Our results provide the opportunity to produce the first ever molecular chronometric analysis of Tarsiidae. These results date the age of crown tarsiers, minimally, to the middle Miocene, and each of the 3 tarsier species groups, Tarsius bancanus, T. syrichta, and the T. tarsier complex, to the early or middle Miocene. Thus, each of these 3 species has evolved in isolation for a period of time that is consistent with that which would be expected for multiple speciation events. Our analysis of the Tarsius tarsier complex reveals 5 subclades, each of which is interpreted to represent a haplogroup at, or above, the species level, a result that is consistent with current hypotheses about numerous cryptic species within this species complex. The implications for conservation within the Sulawesi biogeographic region are that Sulawesi is subdivided into numerous subregions of endemism and that, by extrapolating the example of cryptic tarsier species to other taxa, biodiversity may be underestimated by an order of magnitude. The practical realties of conservation in Sulawesi are such that it is most reasonable to assume that anthropogenic extinctions are occurring, and that some species will go extinct before they have even been identified.

Accuracy of obsidian hydration dating based on obsidian–radiocarbon association and optical microscopy

Most archaeologists using obsidian hydration dating (OHD) in the United States develop hydration rates from association of obsidian hydration rims with dates based on radiocarbon, subsequently using the rate for chronometric analysis. The overall accuracy of the process has never been quantified. This paper reports an accuracy analysis in which sources of uncertainty are defined and modeled and their effects quantified. A Monte Carlo simulation is used to quantify errors from rate development, while uncertainties in age resulting from chronometric analysis are calculated analytically. For typical ranges of error values, hydration rate errors of ∼5% or less are achievable in the absence of systematic errors, with errors of chronometric age estimates ∼20–30% or less.