scholarly journals Statistical Power and Precision of Experimental Studies Originated in the Republic of Turkey from 2010 to 2020: Current Practices and Some Recommendations

2020 ◽  
Author(s):  
Metin Bulus ◽  
Ilhan Koyuncu
Keyword(s):  
Power Analysis ◽  
Statistical Power ◽  
Experimental Studies ◽  
Small Scale ◽  
Cohen’S D ◽  
Ex Ante ◽  
The Republic ◽  
Cohen's D ◽  
Republic Of Turkey ◽  
Education Field

This study systematically reviews randomly selected 155 experimental studies in education field originated in the Republic of Turkey between 2010 and 2020. Indiscriminate choice of sample size in recent publications prompted us to evaluate their statistical power and precision. First, above and beyond our review, we could not identify any large-scale experiments such as cluster-randomized or multisite randomized trials, which overcome shortcomings of small-scale experiments, better suit to the organizational structure of the education field, nevertheless require far greater effort and financial resources. Second, none of the small-scale experiments has reported or conducted ex-ante power analysis. Third, results indicate that studies are sufficiently powered to detect medium to large effects (0.50 < Cohen’s d < 0.80), however they are underpowered to detect small effects (Cohen’s d ≤ 0.20). In other words, they are precise enough to detect medium effects and above (MDES ≥ .50). Finally, trends in the past ten years indicate precision remained unchanged. Findings should be interpreted in light of minimum effects in education that are relevant to education policy and practice. We emphasize the importance of conducting ex-ante power analysis, and encourage the reporting of standardized variance parameters and attrition rates to inform future studies of similar kind.

scholarly journals Wavelet decomposition analysis is a clinically relevant strategy to evaluate cerebrovascular buffering of blood pressure after spinal cord injury

2018 ◽  
Vol 314 (5) ◽  
pp. H1108-H1114 ◽  
Author(s):  
Saqib Saleem ◽  
Diana Vucina ◽  
Zoe Sarafis ◽  
Amanda H. X. Lee ◽  
Jordan W. Squair ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Transfer Function ◽  
Wavelet Decomposition ◽  
Statistical Power ◽  
Decomposition Analysis ◽  
Cohen’S D ◽  
Cord Injury ◽  
Cohen's D

The capacity of the cerebrovasculature to buffer changes in blood pressure (BP) is crucial to prevent stroke, the incidence of which is three- to fourfold elevated after spinal cord injury (SCI). Disruption of descending sympathetic pathways within the spinal cord due to cervical SCI may result in impaired cerebrovascular buffering. Only linear analyses of cerebrovascular buffering of BP, such as transfer function, have been used in SCI research. This approach does not account for inherent nonlinearity and nonstationarity components of cerebrovascular regulation, often depends on perturbations of BP to increase the statistical power, and does not account for the influence of arterial CO2 tension. Here, we used a nonlinear and nonstationary analysis approach termed wavelet decomposition analysis (WDA), which recently identified novel sympathetic influences on cerebrovascular buffering of BP occurring in the ultra-low-frequency range (ULF; 0.02–0.03Hz). WDA does not require BP perturbations and can account for influences of CO2 tension. Supine resting beat-by-beat BP (Finometer), middle cerebral artery blood velocity (transcranial Doppler), and end-tidal CO2 tension were recorded in cervical SCI ( n = 14) and uninjured ( n = 16) individuals. WDA revealed that cerebral blood flow more closely follows changes in BP in the ULF range ( P = 0.0021, Cohen’s d = 0.89), which may be interpreted as an impairment in cerebrovascular buffering of BP. This persisted after accounting for CO2. Transfer function metrics were not different in the ULF range, but phase was reduced at 0.07–0.2 Hz ( P = 0.03, Cohen’s d = 0.31). Sympathetically mediated cerebrovascular buffering of BP is impaired after SCI, and WDA is a powerful strategy for evaluating cerebrovascular buffering in clinical populations.

scholarly journals Effect size, sample size and power of forced swim test assays in mice: Guidelines for investigators to optimize reproducibility

2020 ◽  
Author(s):  
Neil Smalheiser ◽  
Elena E. Graetz ◽  
Zhou Yu ◽  
Jing Wang
Keyword(s):  
Sample Size ◽  
Effect Size ◽  
Statistical Power ◽  
Forced Swim Test ◽  
Real Life ◽  
Swim Test ◽  
Cohen’S D ◽  
Forced Swim ◽  
Cohen's D ◽  
Adequate Power

A recent flood of publications has documented serious problems in scientific reproducibility, power, and reporting of biomedical articles, yet scientists persist in their usual practices. Why? We examined a popular and important preclinical assay, the Forced Swim Test (FST) in mice used to test putative antidepressants. Whether the mice were assayed in a naïve state vs. in a model of depression or stress, and whether the mice were given test agents vs. known antidepressants regarded as positive controls, the mean effect sizes seen in the experiments were indeed extremely large (1.5 – 2.5 in Cohen’s d units); most of the experiments utilized 7-10 animals per group which did have adequate power to reliably detect effects of this magnitude. We propose that this may at least partially explain why investigators using the FST do not perceive intuitively that their experimental designs fall short -- even though proper prospective design would require ~21-26 animals per group to detect, at a minimum, large effects (0.8 in Cohen’s d units) when the true effect of a test agent is unknown. Our data provide explicit parameters and guidance for investigators seeking to carry out prospective power estimation for the FST. More generally, altering the real-life behavior of scientists in planning their experiments may require developing educational tools that allow them to actively visualize the inter-relationships among effect size, sample size, statistical power, and replicability in a direct and intuitive manner.

Implementing bedside rounds to improve patient-centred outcomes: a systematic review

2018 ◽  
Vol 28 (4) ◽  
pp. 317-326 ◽  
Author(s):  
John T Ratelle ◽  
Adam P Sawatsky ◽  
Deanne T Kashiwagi ◽  
Will M Schouten ◽  
Patricia J Erwin ◽  
...  
Keyword(s):  
Patient Experience ◽  
Experimental Studies ◽  
Selective Reporting ◽  
Patient Knowledge ◽  
Adult Care ◽  
Cohen’S D ◽  
Bedside Rounds ◽  
Central Registry ◽  
Patient Reported ◽  
Cohen's D

BackgroundBedside rounds (BR) have been proposed as an ideal method to promote patient-centred hospital care, but there is substantial variation in their implementation and effects. Our objectives were to describe the implementation of BR in hospital settings and determine their effect on patient-centred outcomes.MethodsData sources included Ovid MEDLINE, Ovid Embase, Scopus and Ovid Cochrane Central Registry of Clinical Trials from database inception through 28 July 2017. We included experimental studies comparing BR to another form of rounds in a hospital-based setting (ie, medical/surgical unit, intensive care unit (ICU)) and reporting a quantitative patient-reported or objectively measured clinical outcome. We used random effects models to calculate pooled Cohen's d effect size estimates for the patient knowledge and patient experience outcome domains.ResultsTwenty-nine studies met inclusion criteria, including 20 from adult care (17 non-ICU, 3 ICU), and nine from paediatrics (5 non-ICU, 4 ICU), the majority of which (n=23) were conducted in the USA. Thirteen studies implemented BR with cointerventions as part of a ‘bundle’. Studies most commonly reported outcomes in the domains of patient experience (n=24) and patient knowledge (n=10). We found a small, statistically significant improvement in patient experience with BR (summary Cohen’s d=0.09, 95% CI 0.04 to 0.14, p<0.001, I2=56%), but no significant association between BR and patient knowledge (Cohen’s d=0.21, 95% CI −0.004 to –0.43, p=0.054, I2=92%). Risk of bias was moderate to high, with methodological limitations most often relating to selective reporting, low adherence rates and missing data.ConclusionsBR have been implemented in a variety of hospital settings, often ‘bundled’ with cointerventions. However, BR have demonstrated limited effect on patient-centred outcomes.

scholarly journals Effect size, sample size and power of forced swim test assays in mice: Guidelines for investigators to optimize reproducibility

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0243668
Author(s):  
Neil R. Smalheiser ◽  
Elena E. Graetz ◽  
Zhou Yu ◽  
Jing Wang
Keyword(s):  
Sample Size ◽  
Effect Size ◽  
Statistical Power ◽  
Forced Swim Test ◽  
Real Life ◽  
Swim Test ◽  
Cohen’S D ◽  
Forced Swim ◽  
Cohen's D ◽  
Adequate Power

A recent flood of publications has documented serious problems in scientific reproducibility, power, and reporting of biomedical articles, yet scientists persist in their usual practices. Why? We examined a popular and important preclinical assay, the Forced Swim Test (FST) in mice used to test putative antidepressants. Whether the mice were assayed in a naïve state vs. in a model of depression or stress, and whether the mice were given test agents vs. known antidepressants regarded as positive controls, the mean effect sizes seen in the experiments were indeed extremely large (1.5–2.5 in Cohen’s d units); most of the experiments utilized 7–10 animals per group which did have adequate power to reliably detect effects of this magnitude. We propose that this may at least partially explain why investigators using the FST do not perceive intuitively that their experimental designs fall short—even though proper prospective design would require ~21–26 animals per group to detect, at a minimum, large effects (0.8 in Cohen’s d units) when the true effect of a test agent is unknown. Our data provide explicit parameters and guidance for investigators seeking to carry out prospective power estimation for the FST. More generally, altering the real-life behavior of scientists in planning their experiments may require developing educational tools that allow them to actively visualize the inter-relationships among effect size, sample size, statistical power, and replicability in a direct and intuitive manner.

scholarly journals Effect size, sample size and power of forced swim test assays in mice: Guidelines for investigators to optimize reproducibility

2020 ◽  
Author(s):  
Neil R. Smalheiser ◽  
Elena E. Graetz ◽  
Zhou Yu ◽  
Jing Wang
Keyword(s):  
Sample Size ◽  
Effect Size ◽  
Statistical Power ◽  
Forced Swim Test ◽  
Real Life ◽  
Swim Test ◽  
Cohen’S D ◽  
Forced Swim ◽  
Cohen's D ◽  
Adequate Power

AbstractA recent flood of publications has documented serious problems in scientific reproducibility, power, and reporting of biomedical articles, yet scientists persist in their usual practices. Why? We examined a popular and important preclinical assay, the Forced Swim Test (FST) in mice used to test putative antidepressants. Whether the mice were assayed in a naïve state vs. in a model of depression or stress, and whether the mice were given test agents vs. known antidepressants regarded as positive controls, the mean effect sizes seen in the experiments were indeed extremely large (1.5 – 2.5 in Cohen’s d units); most of the experiments utilized 7-10 animals per group which did have adequate power to reliably detect effects of this magnitude. We propose that this may at least partially explain why investigators using the FST do not perceive intuitively that their experimental designs fall short -- even though proper prospective design would require ~21-26 animals per group to detect, at a minimum, large effects (0.8 in Cohen’s d units) when the true effect of a test agent is unknown. Our data provide explicit parameters and guidance for investigators seeking to carry out prospective power estimation for the FST. More generally, altering the real-life behavior of scientists in planning their experiments may require developing educational tools that allow them to actively visualize the inter-relationships among effect size, sample size, statistical power, and replicability in a direct and intuitive manner.

Phonologische Verarbeitung bei Grundschulkindern mit schwacher Lesefähigkeit

2013 ◽  
Vol 2 (4) ◽  
pp. 199-215 ◽  
Author(s):  
Maria Klatte ◽  
Claudia Steinbrink ◽  
Kirstin Bergström ◽  
Thomas Lachmann
Keyword(s):  
Cohen’S D ◽  
Phonologische Verarbeitung ◽  
Cohen's D

Defizite in der phonologischen Informationsverarbeitung werden heute als Kernsymptom der Lese-Rechtschreibstörung betrachtet. In Trainingsstudien mit betroffenen Kindern erwiesen sich Phonemwahrnehmungsfähigkeiten als trainierbar, und Programme, in denen Aufgaben zur phonologischen Bewusstheit mit der systematischen Vermittlung von Phonem-Graphem-Zuordnungen kombiniert wurden, zeigten Transfereffekte auf Lese- und Rechtschreibleistungen. Ausgehend von diesen Erkenntnissen wurde ein computerbasiertes Trainingsprogramm zur Förderung der Phonemwahrnehmung, der phonologischen Bewusstheit und der Graphem-Phonem-Zuordnungen für deutschsprachige Grundschulkinder mit Lese-Rechtschreibstörung entwickelt. Aufgrund der besonderen Relevanz der Vokallänge für die deutsche Orthographie enthält das Programm neben Aufgaben, die auf Konsonanten fokussieren, auch Vokallängenaufgaben. Bei der Konzipierung des Programms wurden etablierte, ursprünglich für andere Sprachen entwickelte Aufgaben an die deutsche Phonologie angepasst und in ein computerbasiertes Format übersetzt. Im Rahmen der vorliegenden Studie sollte überprüft werden, ob die konstruierten Trainingsaufgaben die spezifischen Defizite von Kindern mit Lese-Rechtschreibstörung wie intendiert abbilden. Hierzu wurden leseschwache Dritt- und Viertklässler (n = 35) mit mindestens durchschnittlichen Lesern derselben Klassenstufen (n = 75; Kontrollgruppe) hinsichtlich ihrer Leistungen in den Aufgaben verglichen. Die leseschwachen Kinder zeigten in allen Aufgaben schlechtere Leistungen als die Kontrollgruppe. Die Effektstärken der Gruppenunterschiede (Cohen's d) lagen im mittleren bis hohen Bereich (0.50 – 2.19). Die Ergebnisse bestätigen, dass die Aufgaben des Trainingsprogramms die spezifischen Defizite leseschwacher Kinder abbilden. Ein Training mit diesen Aufgaben erscheint daher grundsätzlich sinnvoll. Die Wirkungen eines solchen Trainings auf die schriftsprachlichen Leistungen von Kindern mit Lese-Rechtschreibstörung werden in zukünftigen Studien überprüft.

Political Inclusion Reduces Political Prejudice

2019 ◽  
Author(s):  
Jan G. Voelkel ◽  
Dongning Ren ◽  
Mark John Brandt
Keyword(s):  
The Political ◽  
Political Discussion ◽  
Total N ◽  
Cohen’S D ◽  
Promising Strategy ◽  
Political Inclusion ◽  
Cohen's D ◽  
Political Divide ◽  
Scenario Study ◽  
Fair Chance

The political divide is characterized by liberals and conservatives who hold strong prejudice against each other. Here we introduce one possible strategy for reducing political prejudice: political inclusion. We define political inclusion as receiving a fair chance to voice one’s opinions in a discussion of political topics with political outgroup members. This strategy may reduce political prejudice by inducing perceptions of the political outgroup as fair and respectful; however, such a strategy may also highlight conflicting attitudes and worldviews, thereby further exacerbating prejudice. In three preregistered studies (total N = 799), we test if political inclusion reduces or increases prejudice toward the political outgroup. Specifically, political inclusion was manipulated with either an imagined scenario (Study 1) or a concurrent experience in an ostensible online political discussion (Studies 2 &amp; 3). Across all studies, participants who were politically included by political outgroup members reported reduced prejudice toward their outgroup compared to participants in a neutral control condition (Cohen’s d [-0.27, -0.50]). This effect was mediated by perceptions of the political outgroup as fairer and less dissimilar in their worldviews. Our results indicate that political discussions that are politically inclusive do not cause additional prejudice via worldview conflict, but instead give others a feeling of being heard. It is a promising strategy to reduce political prejudice.

RUNTUHNYA KHILAFAH TURKI UTSMANI 3 MARET 1924

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Miftahul Jannah
Keyword(s):  
Third World ◽  
Historical Writing ◽  
Cultural Issues ◽  
Historical Method ◽  
The Past ◽  
The Republic ◽  
Republic Of Turkey

<p align="center"><strong>Abstrak</strong></p><p>Tulisan dalam jurnal ini bertujuan untuk mengetahui proses runtuhnya Khilafah Turki Ustmani tanggal 3 maret 1924 dan dampaknya terhadap kehidupan umat Islam. Metode yang digunakan dalam penelitian ini adalah metode sejarah. Metode sejarah adalah prosedur sejarawan Untuk melukiskan kisah masa lampau berdasarkan jejak-jejak yang ditinggalkan pada masa lampau dengan langkah-langkah penulisan sejarah sebagai berikut: (1) heuristik, (2) kritik, (3) interpretasi dan (4) historiografi. Berdasarkan penelitian yang dilakukan maka dapat ditarik kesimpulan bahwa: Khilafah Turki Ustmani dihancurkan dengan cara menghapus sistem kekhilafahan dan menggantinya dengan sistem republik oleh seorang keturunan yahudi yaitu Mustafa Kemal Attatur. Selama 14 abad kaum muslimin hidup dalam pemerintahan Islam yang mana diterapkan hukum-hukum Islam dalam seluruh aspek kehidupan. Namun sayangnya hari itu tepatnya 3 maret 1924 secara resmi dengan bantuan Inggris, Mustafa Kemal Attaturk mengubah khilafah dengan sistem Repulik Turki dan sampai hari ini sistem tersebut masih berjalan. Runtuhnya khilafah menyebabkan munculnya persoalan kaum muslimin mulai dari kolonialisme, konflik di Negara dunia ketiga, persoalan ekonomi,politik dan sosial budaya.</p><p> </p><p><strong>Kata Kunci:</strong> Khilafah Turki Ustmani, 3 maret 1924</p><p> </p><p align="center"><strong><em>Abstract</em></strong></p><p><em>The writing in this journal aims to find out the process of the collapse of the Ottoman Caliphate on March 3, 1924 and its impact on the lives of Muslims. The method used in this study is the historical method. Historical method is the procedure of historians to describe the story of the past based on traces left in the past by the steps of historical writing as follows: (1) heuristics, (2) criticism, (3) interpretation and (4) historiography.</em></p><p><em>Based on the research conducted, it can be concluded that: the Ottoman Caliphate was destroyed by removing the Caliphate system and replacing it with a republic system by a descendant of the Jews namely Mustafa Kemal Attatur. For 14 centuries the Muslims lived in an Islamic government which applied Islamic laws in all aspects of life. But unfortunately that day to be exact 3 March 1924 officially with the help of Britain, Mustafa Kemal Attaturk changed the Caliphate with the system of the Republic of Turkey and to this day the system is still running. The collapse of the Caliphate caused the emergence of problems of the Muslims ranging from colonialism, conflict in third world countries, economic, political and socio-cultural issues</em><em>.</em></p><p><em> </em></p><strong><em>Keywords:</em></strong><em> the Caliphate of Turkish Ottoman, March 3, 1924</em>

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