Optimizing Differences Between Groups Is Important

Author(s):  
Paul D. Bliese ◽  
Eliza W. Wicher ◽  
Dhuha Abdulsalam

Firms rely on aggregate responses from engagement survey data in order to differentiate between teams of direct reports under specific managers, divisions, business units, etc. In this chapter, the authors show that items vary with respect to being able to differentiate groups and provide concrete and practical information relevant to selecting items used in engagement surveys. Specifically, the authors show how item-level intraclass correlation coefficient type 1 (ICC[1]) values can provide useful information to optimize group differentiation beyond traditional psychometrics. Using multiple examples from applied settings, they provide insights regarding interpreting ICC(1) values, wording of survey items, stability of ICC(1) values, and the difference between ICC(1) values and traditional psychometric values.

2018 ◽  
Vol 15 (1) ◽  
pp. 594
Author(s):  
Mehmet Yıldız ◽  
Uğur Fidan

Many laboratory and field tests are used in the literature to measure agility. The aim of the present study was to investigate the reliability and validity of a new Reactive Agility Test developed for badminton. A total of fourty male [ 20 elites (age: 20.8 ± 2.98 year, height: 174.55 ± 12.03 cm, weight: 65.70 ± 14.41 kg) and 20 sub-elites (age: 22.20±1,51, height: 170.01 ± 05.80 cm, weight: 62.45 ± 6,45 kg)] badminton players took part in the present study. For validity, the difference and relationship between newly developed reactive agility and planned changing direction tests in terms of elit and sub-elit players was examined. In the reliability measurements of test-retest, The Reactive Agility Test at same route was performed twice. Independent sample t test was carried out in order to detect the difference among the groups in the search for validity. The identification of the relations between the two different tests was performed with linear regression analysis. The reliability of test-retest was tried to be estimated with the coefficient of variances and intraclass correlation coefficient, and the Bland Altman method. In addition, a systematic difference between the test and the retest was estimated with the paired t test. At the end of the study, while there was not a significant difference found in the rates of planned changing direction of the elit and sub-elit players, it was detected that reactive agility rates were better in the elit players (7.14±4.85 sec and 9.87±5.07 sec, respectively). Moreover, a high coefficient determination was revealed between two tests (r2: 0.63, p<0.01). In the comparison of test-retest, a high intraclass correlation coefficient (0.930) and a very low coefficient of variances (4.7) were found. Furthermore, it was observed in the Bland Altman graph that a 95% of concordance range of the data obtained between two measurements was a good and narrow concordance.  In conclusion, it was determined that the new developed badminton specific Reactive Agility Test is a valid and reliable measurement method and it is suggested that this test protocol can be used to enhance and monitor reactive agility ability of badminton players.Extended English summary is in the end of Full Text PDF (TURKISH) file. ÖzetLiteratürde çevikliğin ölçülmesi amacıyla birçok laboratuvar ve saha testi kullanılmaktadır. Bu çalışmanın amacı badminton sporuna göre düzenlenmiş Reaktif Çeviklik Testinin güvenirlik ve geçerliğinin araştırılmasıdır. Araştırmaya toplam kırk erkek [20 elit (yaş: 20,8±2,98 yıl, boy uzunluğu: 174,55±12,03 cm, vücut ağırlığı:65,70±14,41 kg) ve 20 sub-elit (yaş: 22,20±1,51 yıl, boy uzunluğu: 170,01±05,80 cm, vücut ağırlığı:62,45±6,45 kg)] badminton oyuncusu katılmıştır. Geçerlik için yeni geliştirilen reaktif çeviklik ile planlı yön değiştirme testlerinin elit ve sub-elit katılımcılar arasındaki istatistiksel karşılaştırması ve ilişkisi analiz edilmiştir. Test-tekrar test güvenirlik ölçümlerinde aynı rotadaki reaktif çeviklik testi birer gün arayla iki kez uygulanmıştır. Geçerlik çalışmasında gruplar arası farkın belirlenmesi için bağımsız değişken t testi ve testler arası ilişkinin fonksiyonel olarak açıklanması ve bu ilişkinin bir modelle tanımlanması için basit doğrusal regresyon analizi yapılmıştır. Test-tekrar test güvenirliği varyasyon katsayısı, sınıf içi korelasyon katsayısı ve Bland Altman metodu ile kestirim edilmiştir. Ayrıca test- tekrar test arasında sistematik bir farkın olup olmadığı eşleştirilmiş t testi ile sınanmıştır.  Çalışma sonunda elit ve sub-elit oyuncuların planlı yön değiştirme bulguları anlamlı bir fark bulunmazken, reaktif çeviklik derecelerinin elit oyuncularda istatistiksel olarak anlamlı farklı (sırasıyla 7,14±4.85 sn ve 9,87±5,07 sn) şekilde düşük olduğu tespit edilmiştir. Bununla beraber her iki test arasında yüksek düzeyde  bir açıklayıcılık katsayısı tespit (r2: 0,63, p<0.01) edilmiştir. Test- tekrar test karşılaştırılmasında yüksek bir sınıf içi korelasyon katsayısı (0,930) ve çok düşük varyasyon katsayısı (4,7) belirlenmiştir. Ayrıca Bland-Altman grafiğinde iki ölçüm arasında elde edilen tüm verilerin %95 uyum aralığının dar ve iyi bir uyum gösterdiği gözlenmiştir. Sonuç olarak,  badminton sporuna göre düzenlenmiş Reaktif Çeviklik Testinin geçerli ve güvenilir bir ölçüm yöntemi olduğu tespit edilmiştir ve badminton oyuncularının reaktif çeviklik becerilerinin geliştirilmesinde ve gelişimlerinin takibinde kullanılabileceği önerilmektedir. 


2009 ◽  
Vol 37 (8) ◽  
pp. 1627-1631 ◽  
Author(s):  
Pieter M. Sengkerij ◽  
Robert-Jan de Vos ◽  
Adam Weir ◽  
Bert J. G. van Weelde ◽  
Johannes L. Tol

Background Power Doppler ultrasonography is widely used to examine neovascularization in midportion Achilles tendinopathy. The reliability of the grading of the degree of neovascularization has not been examined previously. Hypothesis Power Doppler ultrasonography can be performed with a high interobserver reliability to determine the neovascularization score in patients with midportion Achilles tendinopathy. Study Design Case control study (diagnosis); Level of evidence, 4. Methods Thirty-three symptomatic and 17 asymptomatic Achilles tendons from 25 consecutive patients were included for ultrasound examination. Victorian Institute of Sport Assessment–Achilles score was used to assess the severity of the Achilles tendinopathy. Each tendon was scored twice by different radiologists using the modified Öhberg score for neovascularization. Results The intraclass correlation coefficient for interobserver reliability was 0.85. Neovascularization was observed in 70% (23/33) of the symptomatic tendons and in 29% (5/17) of the asymptomatic tendons. The Spearman correlation coefficient between the Victorian Institute of Sport Assessment–Achilles score and the degree of neovascularization was −0.16 (P =. 10). Conclusion An excellent interobserver reliability was found for determining the degree of neovascularization on power Doppler ultrasonography examination. Neovessels were present in a majority of symptomatic tendons. The severity of symptoms was not correlated with the neovascularization score. Clinical Relevance Power Doppler ultrasonography is widely used to evaluate tendinopathy without knowledge of the difference in observations between several testers. Interobserver reliability of the evaluation of the degree of neovascularization in chronic midportion Achilles tendinopathy is excellent.


2020 ◽  
Vol 9 (9) ◽  
pp. 2728 ◽  
Author(s):  
Seo-Hyun Park ◽  
Soo-Hwan Byun ◽  
So-Hee Oh ◽  
Hye-Lim Lee ◽  
Ju-Won Kim ◽  
...  

The advantages of intraoral model scanning have yielded recent developments. However, few studies have explored the orthodontic clinical use of this technique particularly among young patients. This study aimed to evaluate the reliability, reproducibility and validity of the orthodontic measurements: tooth width, arch length and arch length discrepancy in each digital model obtained by model scanner and intraoral scanner, relative to a plaster model. Arch length measured using two methods: curved arch length (CAL) measured automatically by digital program and sum of sectional liner arch length (SLAL) measured sum of anterior and posterior liner arch lengths. Arch length discrepancy calculated each arch length measurement methods: curved arch length discrepancy (CALD) and sum of sectional liner arch length discrepancy (SLALD). Forty young patients were eligible for the study. A plaster model (P), model-scanned digital model (MSD) and intraoral scanned digital model (ISD) were acquired from each patient. The reliability of the measurements was evaluated using Pearson’s correlation coefficient, while the reproducibility was evaluated using the intraclass correlation coefficient. The validity was assessed by a paired t-test. All measurements measured in P, MSD and ISD exhibited good reliability and reproducibility. Most orthodontic measurements despite of CAL in MSD exhibited high validity. Only the SLAL and SLALD in ISD group differed significantly, despite the good validity of the tooth width, CAL and CALD. The measurements based on the digital program appeared high reliability, reproducibility and accurate than conventional measurement. However, SLAL and SLALD in ISD group appeared shorter because of distortion during intraoral scanning. However, this could be compensated by using digital programed curved arch. Although the validity of SLAL and SLALD in the ISD group differed statistically, the difference is not considered clinically significant. Although MSD and ISD are acceptable for a clinical space analysis, clinicians should be aware of digital model-induced errors.


2021 ◽  
Vol 42 (5) ◽  
pp. 376-381
Author(s):  
Seon Hwa Cho ◽  
Young Gyu Cho ◽  
Hyun Ah Park ◽  
A Ra Bong

Background: The ultrasonic stadiometer was originally developed as a device to measure and monitor children’s height. However, an ultrasonic stadiometer (InLab S50; InBody Co., Seoul, Korea) was used to measure adults’ height in the 2018 Korea Community Health Survey (KCHS). This study was conducted to assess the reliability and validity of the InLab S50 in adults. Methods: The study subjects were 120 adults (reliability test, n=20; validity test, n=100) who had visited a health screening center. The intra- and inter-rater reliabilities of InLab S50 were assessed using the intraclass correlation coefficient (ICC). The agreement between InLab S50 and an automatic stadiometer (HM-201; Fanics, Busan, Korea) was assessed using Pearson’s correlation coefficient and Bland-Altman analysis. Results: The intra- and inter-rater reliabilities of the InLab S50 were excellent (ICC=0.9999 and 0.9998, respectively). The correlation coefficient of the height measured by the two measurement devices was very high (r=0.996). The difference (Δheight [HM-201-InLab S50]) was -0.15±0.78 cm (95% limit of agreement [LOA], -1.69 to 1.38). After excluding the values outside 95% LOA, the difference was further reduced to -0.05±0.59 cm (95% LOA, -1.20 to 1.10). Conclusion: This study showed that the InLab S50 is a reliable and valid device for the measurement of adults’ height. Therefore, we think that InLab S50 could be used to measure adults’ height in household health surveys such as the KCHS.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Fernanda Silveira Bello de Barros ◽  
Luiz Cláudio de Silva Bussamra ◽  
Edward Araujo Júnior ◽  
Leonardo da Silva Valladão de Freitas ◽  
Luciano Marcondes Machado Nardozza ◽  
...  

To compare the fetal cerebellum and cisterna magna length measurements by means of two- (2DUS) and three-dimensional (3DUS) ultrasonography using the three-dimensional extended imaging (3D XI), a cross-sectional study with 69 healthy pregnant women between 18 and 24 weeks was performed. For the measurements by 2DUS, the axial planes were used and for the 3DUS a sequence of adjacent axial slices (multislice view). To evaluate the difference between the two techniques, we used the Wilcoxon test. To evaluate the correlation between the cerebellum and cisterna magna length measurements and the gestational age, we used the Spearman correlation coefficient (r). For the calculation of reproducibility, we used the intraclass correlation coefficient (ICC). The mean of the transverse and anterior-posterior diameter of cerebellum and cisterna magna by 3DUS was 9.23 and 6.62 mm, respectively. It was observed that the average of the measurements obtained by 3DUS was significantly higher, 0.76 and 1.02 mm for the length of the cerebellum and cisterna magna, respectively (P<0.001). There was a high correlation between the length measurement of the cerebellum 3D (r=0.940, P<0.001), but low correlation of cisterna magna 3D (r=0.462, P=0.080) with the gestational age. There was good intra- and interobserver reproducibility for the cerebellum and cisterna magna 3D with ICC=0.792 , 0.668, 0.691, and 0.287, respectively. The measurements of the fetal cerebellum and cisterna magna length by 3DUS using the software 3D XI were significantly higher than those obtained by 2DUS.


1994 ◽  
Vol 71 (06) ◽  
pp. 731-736 ◽  
Author(s):  
M W Mansfield ◽  
M H Stickland ◽  
A M Carter ◽  
P J Grant

SummaryTo identify whether genotype contributes to the difference in PAI-1 levels in type 1 and type 2 diabetic subjects and whether genotype relates to the development of retinopathy, a Hind III restriction fragment length polymorphism and two dinucleotide repeat polymorphisms were studied. In 519 Caucasian diabetic subjects (192 type 1, 327 type 2) and 123 Caucasian control subjects there were no differences in the frequency of the Hind III restriction alleles (type 1 vs type 2 vs control: allele 1 0.397 vs 0.420 vs 0.448; allele 2 0.603 vs 0.580 vs 0.552) nor in the allelic frequency at either dinucleotide repeat sequence. In 86 subjects with no retinopathy at 15 years or more from diagnosis of diabetes and 190 subjects with diabetic retinopathy there was no difference in the frequency of Hind III restriction alleles (retinopathy present vs retinopathy absent: allele 1 0.400 vs 0.467; allele 2 0.600 vs 0.533) nor in the allelic frequencies at either dinucleotide repeat sequence. The results indicate that there is no or minimal influence of the PAI-1 gene on either PAI-1 levels or the development of diabetic retinopathy in patients with diabetes mellitus.


Author(s):  
Yu Wang ◽  
Jiantao Wang ◽  
Haiping Wang ◽  
Xinyu Yang ◽  
Liming Chang ◽  
...  

Objective: Accurate assessment of breast tumor size preoperatively is important for the initial decision-making in surgical approach. Therefore, we aimed to compare efficacy of mammography and ultrasonography in ductal carcinoma in situ (DCIS) of breast cancer. Methods: Preoperative mammography and ultrasonography were performed on 104 women with DCIS of breast cancer. We compared the accuracy of each of the imaging modalities with pathological size by Pearson correlation. For each modality, it was considered concordant if the difference between imaging assessment and pathological measurement is less than 0.5cm. Results: At pathological examination tumor size ranged from 0.4cm to 7.2cm in largest diameter. For mammographically determined size versus pathological size, correlation coefficient of r was 0.786 and for ultrasonography it was 0.651. Grouped by breast composition, in almost entirely fatty and scattered areas of fibroglandular dense breast, correlation coefficient of r was 0.790 for mammography and 0.678 for ultrasonography; in heterogeneously dense and extremely dense breast, correlation coefficient of r was 0.770 for mammography and 0.548 for ultrasonography. In microcalcification positive group, coeffient of r was 0.772 for mammography and 0.570 for ultrasonography. In microcalcification negative group, coeffient of r was 0.806 for mammography and 0.783 for ultrasonography. Conclusion: Mammography was more accurate than ultrasonography in measuring the largest cancer diameter in DCIS of breast cancer. The correlation coefficient improved in the group of almost entirely fatty/ scattered areas of fibroglandular dense breast or in microcalcification negative group.


2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Bo Zhang ◽  
Jianjun Gu ◽  
Xiaoxiao Zhang ◽  
Bin Yang ◽  
Zheng Wang ◽  
...  

Purpose. To explore the probability and variation in biomechanical measurements of rabbit cornea by a modified Scheimpflug device.Methods. A modified Scheimpflug device was developed by imaging anterior segment of the model imitating the intact eye at various posterior pressures. The eight isolated rabbit corneas were mounted on the Barron artificial chamber and images of the anterior segment were taken at posterior pressures of 15, 30, 45, 60, and 75 mmHg by the device. The repeatability and reliability of the parameters including CCT, ACD, ACV, and CV were evaluated at each posterior pressure. All the variations of the parameters at the different posterior pressures were calculated.Results. All parameters showed good intraobserver reliability (Cronbach’s alpha; intraclass correlation coefficient,α, ICC > 0.96) and repeatability in the modified Scheimpflug device. With the increase of posterior pressures, the ratio of CCT decreased linearly and the bulk modulus gradually reduced to a platform. The increase of ACD was almost linear with the posterior pressures elevated.Conclusions. The modified Scheimpflug device was a valuable tool to investigate the biomechanics of the cornea. The posterior pressure 15–75 mmHg range produced small viscoelastic deformations and nearly linear pressure-deformation response in the rabbit cornea.


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