Evaluating precision and repeatability of hand calipers

2016 ◽  
Vol 38 (2) ◽  
pp. 162-182 ◽  
Author(s):  
Steven G H Dorland
Keyword(s):  
Individual Variation ◽  
Coefficient Of Variation ◽  
Repeated Measures ◽  
Statistical Difference ◽  
Thought Processes ◽  
Variation Analysis ◽  
Repeated Measures Anova ◽  
Observer Error ◽  
Micro Scale ◽  
Effective Metric

Often, statistical evaluations of metric data are overlooked in ceramic studies. This paper evaluates degrees of precision and repeatability through the application of a coefficient of variation analysis and a repeated measures ANOVA. First, the author assessed the use of calipers for measuring metric data that pertains to decorative elements. Second, the author assessed the degree of statistical difference between measurements taken and measurements that have been rounded, a technique used to account for intra-observer error. The results demonstrate that the precision and repeatability of calipers is suitable for effectively measuring metric data values, and the precision of non-rounded values does not differ greatly from rounded values. The author argues that calipers are an effective metric measuring aid that further contribute to studies of personal actions and thought processes of potters. As a result, archaeological focus can integrate a micro-scale understanding of potting communities to consider finding individual variation and the learning landscapes of inexperienced potters.

scholarly journals Within-session variability as quality control for oscillometry in health and disease

2021 ◽  
pp. 00074-2021
Author(s):  
Louise M. Harkness ◽  
Kieran Patel ◽  
Farid Sanai ◽  
Sandra Rutting ◽  
Alice M. Cottee ◽  
...  
Keyword(s):  
Quality Control ◽  
Coefficient Of Variation ◽  
Repeated Measures ◽  
Optimal Number ◽  
Medical Systems ◽  
Repeated Measures Anova ◽  
Copd Patients ◽  
Adult Participants ◽  
Health And Disease ◽  
Post Hoc

Oscillometry is increasingly adopted in respiratory clinics, however many recommendations regarding measurement settings and quality control remain subjective. The aim of this study was to investigate the optimal number of measurements and acceptable within-session coefficient of variation (CoV) in health, asthma and COPD.Fifteen healthy, 15 asthma and 15 COPD adult participants were recruited. Eight consecutive 30 s measurements were made using an oscillometry device (tremoFlo C-100, Thorays Thoracic Medical Systems Inc., Canada) from which resistance at 5 Hz (Rrs5) was examined. The effect of progressively including a greater number of measurements on Rrs5 and its within-session coefficient of variation (CoV) was investigated. Data was analysed using one-way repeated measures ANOVA with Bonferroni post-hoc test.The CoV(Rrs5) of the first 3 measurements was 6.7±4.7%, 9.7±5.7%, and 12.6±11.2% in healthy, asthma and COPD participants, respectively. Both mean Rrs5 and CoV(Rrs5) were not statistically different when progressively including 4–8 measurements. Selecting the 3 closest Rrs5 values over an increasing number of measurements progressively decreased the CoV(Rrs5). In order for ≥95% of participants to fall within a target CoV(Rrs5) of 10%, ≥4, 5 and 6 measurements were needed in health, asthma, and COPD, respectively.Within-session variability of oscillometry is increased in disease. Furthermore, the higher number of measurements required to achieve a set target for asthma and COPD patients may not be practical in a clinical setting. Provided technical acceptability of measurements is established, i.e. by removing artefacts and outliers, then a CoV of 10% is a marker of quality in most patients, but we suggest higher CoVs upto 15–20% should still be reportable.

scholarly journals Across the Spectrum from Borderline Dysplasia to Global Pincer Femoroacetabular Impingement: Arthroscopic Outcomes from a Large Hip Arthroscopy Study Group

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0034
Author(s):  
Benjamin Kivlan ◽  
Shane Nho ◽  
Andrew Wolff ◽  
John Salvo ◽  
John Christoforetti ◽  
...  
Keyword(s):  
Hip Arthroscopy ◽  
Repeated Measures ◽  
Statistical Difference ◽  
Acetabular Coverage ◽  
Repeated Measures Anova ◽  
Edge Angle ◽  
Center Edge ◽  
Lateral Center Edge Angle ◽  
Center Edge Angle ◽  
Acetabular Overcoverage

Objectives: Outcomes from hip arthroscopy for dysplasia and global pincer FAI have fallen short of those for patients with normal acetabular coverage, but no study has investigated arthroscopic outcomes across the spectrum of acetabular coverage. Our objective is to report comparative hip arthroscopic outcomes of patients with low (borderline dysplasia), normal, and high (global pincer FAI) lateral acetabular coverage. Methods: A retrospective analysis of prospectively-collected data from a large multi-center registry (seven United States centers) was performed. Primary hip arthroscopy patients were assigned to one of three groups based on preoperative lateral center-edge angle (LCEA): borderline dysplasia (≤25°), normal (26-38°), and pincer FAI (≥39°). Repeated measures ANOVA compared pre-operative to 2-year minimum post-operative iHOT-12 scores. Subsequent ANOVA determined the effect of acetabular coverage on magnitude of change in scores. Results: Of 437 patients, the only statistical difference between groups was lower prevalence of acetabuloplasty in the borderline dysplasia group (p=0.001). A significant improvement in the pre-operative to post-operative iHOT-12 scores for patients with normal acetabular coverage, acetabular undercoverage, and acetabular overcoverage was observed; F(1, 339)=311.06; p<0.001, with no statistical differences in pre-operative (p=0.505) and post-operative (p<0.488) iHOT-12 scores when comparing the groups based on acetabular coverage. Mean iHOT-12 scores increased from 37.3 pre-operatively to 68.7 postoperatively, p<0.001, in the borderline dysplasia group, from 34.4 to 72, p<0.001, in the normal coverage group, and from 35.3 to 69.4, p<0.001, in the pincer group. These pre-operative scores increased by 31.4, 37.8, and 34.1, respectively, with no effect for acetabular coverage on the magnitude of change from pre-operative to post-operative iHOT-12 scores, F(2,339) =1.18; p=0.310. 10 subjects (2.3%) underwent conversion arthroplasty and 19 patients (4.4%) underwent revision arthroscopy with no significant effect of acetabular coverage on the incidence of revision or conversion surgery, X2 (6,433)=11.535, P = 0.073. Conclusion: Lateral acetabular coverage did not influence outcomes from primary hip arthroscopy performed in patients with low (borderline dysplasia), normal, and high (global pincer FAI) LCEA. Borderline dysplasia and moderate global pincer FAI with no or minimal osteoarthritis do not compromise successful 2-year minimum outcomes or survivorship following primary hip arthroscopy when performed by experienced surgeons.

scholarly journals A PILOT ANALYSIS: CAN THE BULGARIAN SPLIT-SQUAT POTENTIATE SPRINT ACCELERATION IN STRENGTH-TRAINED MEN?

2018 ◽  
Vol 15 (3) ◽  
pp. 453 ◽  
Author(s):  
Robert George Lockie ◽  
Ashley Orjalo ◽  
Matthew Moreno
Keyword(s):  
Individual Variation ◽  
Repeated Measures ◽  
Peak Power ◽  
Relative Strength ◽  
Sprint Performance ◽  
The Other ◽  
Repeated Measures Anova ◽  
Repetition Maximum ◽  
Position Transducer

This study determined whether a five repetition-maximum Bulgarian split-squat (5RM BSS) could potentiate a 0-5, 0-10, and 0-20 m (meter) sprint performance. Seven men were assessed in the 5RM BSS (a linear position transducer measured peak power [PP] and force [PF] for each leg), and completed two post activation potentiation (PAP) sessions. One session involved a control condition (CC) of 4 minutes (min) rest; the other the 5RM BSS. Participants were assessed in baseline sprints, and sprints of 15 seconds, 2, 4, 8, 12, and 16 min post-PAP intervention. A repeated measures ANOVA (p < 0.05) calculated significant changes in sprint times. The best potentiated time for each interval was also compared to the baseline. Spearman’s correlations (r; p < 0.05) calculated relationships between absolute and relative strength, PP and PF, with percent potentiation in sprint times. The BSS did not potentiate speed at any time, although there was great individual variation. The best 0-5 m time was significantly different from the baseline (p = 0.022), with no differences between PAP conditions. Significant correlations were found between strength and sprint potentiation at 16 min for the 0-5 m interval, and at 8 min and the best times for the 0-20 m interval (r = -0.786 to -0.893). There were correlations between PP and PF for each leg with sprint potentiation from 2-12 min across all intervals (r = -0.786 to -0.964). Stronger individuals who generate greater PP and PF in a 5RM BSS will be more likely to potentiate 20-m sprint performance.

One Size Fits All?

Methodology ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Manuel C. Voelkle ◽  
Patrick E. McKnight
Keyword(s):  
Repeated Measures ◽  
Structural Equation ◽  
Type I Error ◽  
Equation Modeling ◽  
Type I ◽  
Finite Sample ◽  
Traditional Methods ◽  
Repeated Measures Anova ◽  
Special Cases ◽  
Latent Curve

The use of latent curve models (LCMs) has increased almost exponentially during the last decade. Oftentimes, researchers regard LCM as a “new” method to analyze change with little attention paid to the fact that the technique was originally introduced as an “alternative to standard repeated measures ANOVA and first-order auto-regressive methods” (Meredith & Tisak, 1990, p. 107). In the first part of the paper, this close relationship is reviewed, and it is demonstrated how “traditional” methods, such as the repeated measures ANOVA, and MANOVA, can be formulated as LCMs. Given that latent curve modeling is essentially a large-sample technique, compared to “traditional” finite-sample approaches, the second part of the paper addresses the question to what degree the more flexible LCMs can actually replace some of the older tests by means of a Monte-Carlo simulation. In addition, a structural equation modeling alternative to Mauchly’s (1940) test of sphericity is explored. Although “traditional” methods may be expressed as special cases of more general LCMs, we found the equivalence holds only asymptotically. For practical purposes, however, no approach always outperformed the other alternatives in terms of power and type I error, so the best method to be used depends on the situation. We provide detailed recommendations of when to use which method.

Time of imagery’s effect on performance and self-efficacy in college baseball players

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Colton Haight ◽  
Sandra Moritz ◽  
Tanis Walch
Keyword(s):  
Self Efficacy ◽  
Repeated Measures ◽  
Group Interaction ◽  
Physical Effect ◽  
Baseball Players ◽  
Repeated Measures Anova ◽  
Significant Time ◽  
Imagery Group ◽  
College Baseball ◽  
Group 2

AbstractThe relationships among the time of imagery use on performance and self-efficacy in college baseball players during a hitting task was examined. Participants (n=24) were randomly assigned to one of three imagery conditions: (a) before practice, (b) during practice, (c) after practice. A one-shot MG-M imagery intervention was used. Results from a 3 (imagery group) ×2 (pretest and posttest) repeated measures ANOVA showed only a significant time by imagery group interaction for self-efficacy (F (2, 21)=4.67, p<0.05). These findings suggest that imagery had a stronger psychological effect than physical effect.

scholarly journals Differences in Graphomotor Skills by the Writing Medium and Children’s Gender

2021 ◽  
Vol 11 (4) ◽  
pp. 162
Author(s):  
Boram No ◽  
Naya Choi
Keyword(s):  
Preschool Children ◽  
Repeated Measures ◽  
Repeated Measures Anova ◽  
Surface Textures ◽  
Young Learners ◽  
And Gender ◽  
Print Size ◽  
Writing Practice ◽  
Pressure Analysis

Factors of graphomotor skills may serve as indicators to determine a writer’s handwriting proficiency or acclimation to different writing surface textures. This study examines differences in children’s graphomotor skills based on types of writing medium and gender. Participants were 97 six-year-old Korean preschool children who had not received formal writing training prior to the study. Writing tasks were completed on a tablet screen and paper. Writing samples were analyzed using the Eye and Pen software to investigate spatial, temporal, and pressure exertion exhibited during the writing tasks. A repeated measures ANOVA revealed differences in graphomotor skills such as print size, writing speed, and writing pressure. Writing on a tablet screen decreased clarity of writing; print size and speed increased as the stylus slides across the tablet surface with relatively less friction, thereby decreasing the exertion of writing pressure. Analysis of writing differences according to gender indicated that boys generated larger print sizes than girls. Results suggest that while simple writing tasks may be feasible on the tablet screen, providing children with a larger writing medium and encouraging larger print sizes for writing practice, especially for boys, may be beneficial in the development of graphomotor skills among young learners.

scholarly journals Microhardness evaluation of root dentin after using resin sealer solvents

2021 ◽  
Vol 15 (4) ◽  
pp. 256-261
Author(s):  
Gamze Nalci ◽  
Tayfun Alaçam ◽  
Bülent Altukaynak
Keyword(s):  
Repeated Measures ◽  
Saline Solution ◽  
Prolonged Exposure ◽  
Repeated Measures Anova ◽  
Ultrasonic Agitation ◽  
Gutta Percha ◽  
Before And After ◽  
Root Dentin ◽  
Substantial Decline ◽  
Hardness Values

Background. This study aimed to assess the effects of methyl ethyl ketone (MEK) and ethyl acetate (EA) on dentin microhardness, used as resin sealer solvents. Methods. Eighty halves of single-rooted teeth were randomly divided into four groups to apply MEK, EA, chloroform, or saline solution. Vickers hardness values were measured for three root levels before and after the direct application of solvents for 5 and 15 minutes or a 1-minute application with ultrasonic agitation. The results were analyzed using repeated-measures ANOVA, and adjustments were made for comparisons with Bonferroni tests. Results. The dentin microhardness decreased in all the solvent groups (P<0.05). The changes in microhardness increased with prolonged exposure times, except for the saline solution group. Chloroform exhibited the most significant decrease in value. Furthermore, ultrasonic agitation elicited a more substantial decline in values. Conclusion. MEK and EA might be preferred over chloroform as a solvent for resin sealers because they offer an attenuated decrease in dentin microhardness and do not have gutta-percha-dissolving properties.

scholarly journals Analyzing randomized controlled interventions: Three notes for applied linguists

2015 ◽  
Vol 5 (1) ◽  
pp. 135-152 ◽  
Author(s):  
Jan Vanhove
Keyword(s):  
Repeated Measures ◽  
Intervention Studies ◽  
Mixed Effects ◽  
Analysis Of Covariance ◽  
Cluster Randomization ◽  
Repeated Measures Anova ◽  
Randomized Controlled ◽  
Mixed Effects Modeling ◽  
Statistical Formalism ◽  
Relevant Covariates

I discuss three common practices that obfuscate or invalidate the statistical analysis of randomized controlled interventions in applied linguistics. These are (a) checking whether randomization produced groups that are balanced on a number of possibly relevant covariates, (b) using repeated measures ANOVA to analyze pretest-posttest designs, and (c) using traditional significance tests to analyze interventions in which whole groups were assigned to the conditions (cluster randomization). The first practice is labeled superfluous, and taking full advantage of important covariates regardless of balance is recommended. The second is needlessly complicated, and analysis of covariance is recommended as a more powerful alternative. The third produces dramatic inferential errors, which are largely, though not entirely, avoided when mixed-effects modeling is used. This discussion is geared towards applied linguists who need to design, analyze, or assess intervention studies or other randomized controlled trials. Statistical formalism is kept to a minimum throughout.

scholarly journals Optimal use of statistical methods to validate reference gene stability in longitudinal studies

2019 ◽  
Author(s):  
Venkat Krishnan Sundaram ◽  
Nirmal Kumar Sampathkumar ◽  
Charbel Massaad ◽  
Julien Grenier
Keyword(s):  
Statistical Methods ◽  
Reference Gene ◽  
Coefficient Of Variation ◽  
Reference Genes ◽  
Developmental Studies ◽  
Variation Analysis ◽  
Reference Gene Stability ◽  
Statistical Approaches ◽  
The Stability ◽  
Gene Stability

AbstractMultiple statistical approaches have been proposed to validate reference genes in qPCR assays. However, conflicting results from these statistical methods pose a major hurdle in the choice of the best reference genes. Indeed, as their respective approaches to calculating reference gene stability is different, their suitability has to be tested for a given experimental setting. In this study, the stability of 10 candidate reference genes (Actb, Gapdh, Tbp, Sdha, Pgk1, Ppia, Rpl13a, Hsp60, Mrpl10, Rps26) was assessed using four common statistical approaches (GeNorm, NormFinder, Coefficient of Variation analysis and Pairwise ΔCt method) in a longitudinal setting. We used the development of the cerebellum and the spinal cord of mice as a model to assess the suitability of these statistical methods for reference gene validation. GeNorm and the Pairwise ΔCt were found to be ill suited due to a fundamental assumption in their stability calculations. Whereas, NormFinder and Coefficient of Variation analysis fare better provided they are used complementarily. We therefore devised a workflow combining these two methods for validating reference genes in developmental studies. This workflow proves to be more robust than any of the methods used individually.

scholarly journals Αξιολόγηση της πρώιμης νευροεξελικτικής παρέμβασης στη νευροαναπτυξιακή πορεία πρόωρων νεογνών υψηλού κινδύνου

2012 ◽  
Author(s):  
Μαρία Κυριακίδου
Keyword(s):  
Repeated Measures ◽  
T Test ◽  
Repeated Measures Anova ◽  
Kolmogorov Smirnov ◽  
One Way Anova

Τα ποσοστά θνητότητας των υψηλού κινδύνου πρόωρων νεογνών έχουν σταθεροποιηθεί και συνεπώς η μελέτη των στρατηγικών μείωσης των υψηλών ποσοστών νευροαναπτυξιακών διαταραχών είναι απαραίτητη. Τα υψηλού κινδύνου πρόωρα νεογνά πρέπει να συμμετέχουν σε προγράμματα πρώιμης παρέμβασης από πολύ νωρίς, λόγω της αυξημένης πλαστικότητας του αναπτυσσόμενου εγκεφάλου. Παρόλα αυτά, η αποτελεσματικότητα της παρέμβασης σε όλα τα ΥΚ πρόωρα νεογνά δεν είναι ξεκάθαρη. Έχει αποδειχτεί, ότι οι πρώιμες αναπτυξιακές παρεμβάσεις που ξεκινούν μετά την έξοδο από το νοσοκομείο, βελτιώνουν τη γνωστική ανάπτυξη των νεογνών αλλά το αποτέλεσμα αυτό δε διατηρείται στη σχολική ηλικία. Η απόδειξη των επιδράσεων της πρώιμης παρέμβασης στην κινητική ανάπτυξη είναι ελλιπής. Επομένως, στόχος της παρούσας μελέτης ήταν να αξιολογήσει την επίδραση της πρώιμης παρέμβασης με τη μέθοδο NDT στη γνωστική και κινητική έκβαση ΥΚ πρόωρων νεογνών, μέχρι τη διορθωμένη ηλικία των 18 μηνών αλλά και να συσχετίσει νεογνικούς και περιγεννηρικούς παράγοντες με τη γνωστική και κινητική έκβαση. Στη μελέτη εισήχθησαν νεογνά με ΔΚ≤32 εβδομάδων και ΒΓ≤1500 γραμμαρίων. Αποκλείστηκαν, νεογνά με χρωματοσωμικές ανωμαλίες, μείζονες συγγενείς ανωμαλίες και γενετικά σύνδρομα. Επίσης, αποκλείστηκαν τα νεογνά που στη διορθωμένη ηλικία των 18 μηνών διαγνώστηκαν με εγκεφαλική παράλυση. Συνολικά, 147 νεογνά πληρούσαν τα κριτήρια εισαγωγής και εφαρμόστηκε η δοκιμασία ΤΙΜΡ στη ΔΗ των 38-41 εβδομάδων. Από αυτά, 73 τυχαιοποιήθηκαν στην ομάδα παρέμβασης και 74 στην ομάδα ελέγχου. Η ομάδα παρέμβασης ακολούθησε πρόγραμμα φυσικοθεραπείας με τη μέθοδο NDT με συχνότητα 2 φορές την εβδομάδα, για ένα έτος ενώ η ομάδα ελέγχου εφάρμοσε πρόγραμμα οδηγιών στο σπίτι 2 φορές την εβδομάδα, για ένα έτος. Στη στατιστική ανάλυση χρησιμοποιήθηκε το t-test, η one-way ANOVA, ο έλεγχος χ² κατά Pearson, repeated measures ANOVA και ο έλεγχος κατά Greenhouse-Geisser. Επιπρόσθετα, χρησιμοποιήθηκε ο έλεγχος Kolmogorov-Smirnov. Το ΒΓ και η ΔΚ των νεογνών στις δύο ομάδες ήταν 1325,18 (±368,46) γρ και 30,55 (±1,6) εβδ, αντίστοιχα, στην ομάδα παρέμβασης και 1440,18 (±293,61) και 30,76 (±1,6) στην ομάδα ελέγχου, αντίστοιχα. Η διαφορά δεν ήταν στατιστικά σημαντική. Οι δύο ομάδες ήταν συγκρίσιμες ως προς τους περιγεννητικούς και νεογνικούς παράγοντες . Οι 2 ομάδες αξιολογήθηκαν στη διορθωμένη ηλικία των 3, 6, 12 και 18 μηνών. Οι δύο ομάδες είχαν στατιστικά σημαντική διαφορά στη διορθωμένη ηλικία των 3, 12 και 18 μηνών στη γνωστική και κινητική έκβαση με την ομάδα παρέμβασης να υπερέχει. Στη διορθωμένη ηλικία των 18 μηνών, η ομάδα παρέμβασης σημείωσε μέση βαθμολογία 108,83 (±9,39) στη γνωστική κλίμακα και 109,01 (±10,30) στην κινητική ενώ η ομάδα ελέγχου 99,18 (±7,31) στη γνωστική και 98,81 (±8,91) στην κινητική κλίμακα της δοκιμασίας Bayley III. Η φυσικοθεραπεία (p<0,0001), η IVH (p<0,0001), η πολυδυμία (p=0,008), η ΝΕΚ (p=0,001) και η διάρκεια χορήγησης Ο₂ (p=0,008) επηρέασαν σημαντικά στη βαθμολογία της γνωστικής έκβασης των πρόωρων νεογνών στη διορθωμένη ηλικία των 18 μηνών. Η φυσικοθεραπεία (p<0,0001), ήταν ο μοναδικός παράγοντας που επηρέασε σημαντικά τη βαθμολογία της κινητικής έκβασης των πρόωρων νεογνών στη διορθωμένη ηλικία των 18 μηνών. Τα ΥΚΠΝ επωφελούνται από το πρόγραμμα πρώιμης παρέμβασης με τη μέθοδο NDT, διότι βελτιώνουν την κινητική και γνωστική τους έκβαση μέχρι τη διορθωμένη ηλικία των 18 μηνών. Ως εκ τούτου, συστήνεται η εφαρμογή της μεθόδου κατά τη διάρκεια του 1ου έτους ζωής ως προληπτικό πρόγραμμα θεραπείας στα ΥΚΠΝ. Αδιαμφισβήτητα, μεγαλύτερης διάρκειας μακροχρόνιες παρακολουθήσεις απαιτούνται για να επιβεβαιώσουν ή να απορρίψουν τη διατήρηση των αποτελεσμάτων στην προσχολική ή σχολική ηλικία. Συστήνεται, ο παράγοντας φυσικοθεραπευτική παρέμβαση να συνυπολογίζεται στις πολυπαραγοντικές αναλύσεις διότι οδηγεί σε αξιόπιστη ερμηνεία των αποτελεσμάτων που αφορούν την έκβαση.

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