Relative Power of the Wilcoxon Test, the Friedman Test, and Repeated-Measures ANOVA on Ranks

1993 ◽  
Vol 62 (1) ◽  
pp. 75-86 ◽  
Author(s):  
Donald W. Zimmerman ◽  
Bruno D. Zumbo
2020 ◽  
Vol 9 (11) ◽  
pp. 3687
Author(s):  
Ana F. Pereira-da-Mota ◽  
Jéssica Costa ◽  
Ana Amorim-de-Sousa ◽  
José M. González-Méijome ◽  
António Queirós

This study aimed to evaluate the effects of two months of orthokeratology (OK) treatment in the accommodative response of young adult myopes. Twenty eyes (21.8 ± 1.8 years) were fitted with the Paragon CRT® 100 LENS to treat myopia between −1.00 and −2.00 D. Low- and high-contrast visual acuity (LCDVA and HCDVA), central objective refraction, light disturbance (LD), and objective accommodative response (using the Grand Seiko WAM-5500 open-field autorefractometer coupled with a Badal system) were measured at baseline (BL) before lens wear and after 1, 15, 30, and 60 nights of OK. Refractive error correction was achieved during the first fifty days of OK lens wear, with minimal changes afterwards. LD analysis showed a transient increase followed by a reduction to baseline levels over the first 30 nights of treatment. The accommodative response was lower than expected for all target vergences in all visits (BL: 0.61 D at 1.00 D to 0.96 D at 5.00 D; 60 N: 0.36 D at 1.00 D to 0.79 D at 5.00 D). On average, the accommodative lag decreases over time with OK lens wear. However, these differences were not statistically significant (p > 0.050, repeated-measures ANOVA and Friedman test). This shows that overnight OK treatment does not affect objectively measured the accommodative response of young, low myopic eyes after two months of treatment stabilization.


2019 ◽  
Author(s):  
Prana Ugiana Gio

This article explains statistical method, namely repeated-measures ANOVA and Friedman Test using SPSS and STATCAL (R)


Methodology ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Manuel C. Voelkle ◽  
Patrick E. McKnight

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.


Author(s):  
Colton Haight ◽  
Sandra Moritz ◽  
Tanis Walch

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.


2021 ◽  
Vol 11 (4) ◽  
pp. 162
Author(s):  
Boram No ◽  
Naya Choi

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.


2021 ◽  
Vol 15 (4) ◽  
pp. 256-261
Author(s):  
Gamze Nalci ◽  
Tayfun Alaçam ◽  
Bülent Altukaynak

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.


2015 ◽  
Vol 5 (1) ◽  
pp. 135-152 ◽  
Author(s):  
Jan Vanhove

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.


2012 ◽  
Author(s):  
Μαρία Κυριακίδου

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.


2018 ◽  
Vol 81 (4) ◽  
pp. 404-413 ◽  
Author(s):  
Zdzisław Lewandowski ◽  
Dariusz P. Danel

Abstract Human lips are one of the most sexually dimorphic facial features. Although lip morphology is considered particularly important for female facial attractiveness no systematic empirical study has been conducted in this respect. This study aimed to investigate a relationship between female Caucasian facial attractiveness and their lip morphology. Two series of morphologically average composite portraits with digitally increased and decreased lip width and height measurements were assessed by adult men and women. Results were analysed using repeated measures ANOVA. When compared to the average lip shape both a decrease and an increase in lip width were associated with lower female facial attractiveness. A systematic increase in lip height from the lowest values to the highest, was associated with an increase in attractiveness scores. Attractiveness assessments of men and women did not differ significantly. The results show that perception of lip attractiveness may be intersexually congruent and that a variation in lip morphology may significantly affect female facial attractiveness.


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