Multiple Comparisons among Means

Dunn, Olive Jean

doi:10.1080/01621459.1961.10482090

Cited by 3,408 publications

(1,086 citation statements)

References 2 publications

Supporting

Mentioning

967

Contrasting

Unclassified

Order By: Relevance

“…Analyses were conducted using the R package MuMIn version 1.15.6 (Barton, 2016). We tested the significance of the differences in mean ω among the twelve predictors using a Kruskal–Wallis test (Hollander & Wolfe, 1973), followed by a post hoc Dunn test (Dunn, 1961) to check the significance of pairwise differences, using the R package “ dunn.test” version 1.3.5.…”

Section: Methodsmentioning

confidence: 99%

Geographic isolation and larval dispersal shape seascape genetic patterns differently according to spatial scale

Dalongeville

Andrello

Mouillot

et al. 2018

Evolutionary Applications

View full text Add to dashboard Cite

Genetic variation, as a basis of evolutionary change, allows species to adapt and persist in different climates and environments. Yet, a comprehensive assessment of the drivers of genetic variation at different spatial scales is still missing in marine ecosystems. Here, we investigated the influence of environment, geographic isolation, and larval dispersal on the variation in allele frequencies, using an extensive spatial sampling (47 locations) of the striped red mullet (Mullus surmuletus) in the Mediterranean Sea. Univariate multiple regressions were used to test the influence of environment (salinity and temperature), geographic isolation, and larval dispersal on single nucleotide polymorphism (SNP) allele frequencies. We used Moran's eigenvector maps (db‐MEMs) and asymmetric eigenvector maps (AEMs) to decompose geographic and dispersal distances in predictors representing different spatial scales. We found that salinity and temperature had only a weak effect on the variation in allele frequencies. Our results revealed the predominance of geographic isolation to explain variation in allele frequencies at large spatial scale (>1,000 km), while larval dispersal was the major predictor at smaller spatial scale (<1,000 km). Our findings stress the importance of including spatial scales to understand the drivers of spatial genetic variation. We suggest that larval dispersal allows to maintain gene flows at small to intermediate scale, while at broad scale, genetic variation may be mostly shaped by adult mobility, demographic history, or multigenerational stepping‐stone dispersal. These findings bring out important spatial scale considerations to account for in the design of a protected area network that would efficiently enhance protection and persistence capacity of marine species.

show abstract

Section: Methodsmentioning

confidence: 99%

Geographic isolation and larval dispersal shape seascape genetic patterns differently according to spatial scale

Dalongeville

Andrello

Mouillot

et al. 2018

Evolutionary Applications

View full text Add to dashboard Cite

show abstract

“…We used the Bonferroni method to correct for familywise error (false positives) when doing multiple comparisons (Dunn 1961). Using the traditional value of 0.05 to define the significance threshold, we divided 0.05 by the number of comparisons, 13, to redefine the threshold for significance for this study.…”

Section: English Language Competence Study Methodsmentioning

confidence: 99%

A comparison of the effects of text-based instruction versus standards-based instruction in the early years

Grossen¹,

Muthukrishna

Naidoo

2016

SAJCE

View full text Add to dashboard Cite

The purpose of the study was to evaluate the effectiveness of a text-based (TB) English structured language development programme and a teacher-designed standards-based (SB) English instructional model. The sample of this study comprised of 500 Samoan children, in Kindergarten (K) and Grade 1 (G1), on the island of American Samoa attending eight different schools. All the children enter school with no English competence. Six schools implemented the TB Language for Learning scripted programme and the Read Well. Two schools implemented the SB instructional model for English language development (SB), and only one of these schools implemented the SB instruction in reading. The results of this study support the efficacy of TB structured language programme as compared to the teacher-designed SB instructional model in all language and reading skills assessed.

show abstract

“…There were significant differences in oxidation rates for all columns at the different temperatures (p < 0.01). Post hoc T-tests with the Bonferonni correction were used to compare oxidation rates at the various temperatures in pairs (Dunn 1961). Oxidation rates for all columns were statistically higher at 31°C than at 22°C; oxidation rates at 22°C were statistically higher than at 4°C.…”

Section: Statisticsmentioning

confidence: 99%

“…P-values are the estimated probability that a null hypothesis should be rejected, where the null hypothesis is that data sets are not significantly different (Montgomery and Runger 2014 When multiple comparisons are made using T-tests, a "Bonferroni correction" is applied to reduce compounding of Type I errors (Dunn 1961). The Bonferroni correction divides alpha by the number of post-hoc comparisons made.…”

Section: Ii) Data Correlationmentioning

confidence: 99%

Pore-gas dynamics in overburden and reclamation soil covers

ScaleKyle

FlemingIan

2019

Environmental Geotechnics

View full text Add to dashboard Cite

Large above-grade overburden landforms comprised of low-grade lean oil sands (LOS) are amassed during the surface mining of oil sands in northern Alberta, Canada. Reclamation soil covers consisting of locally-salvaged soils are subsequently placed above the LOS landforms in single and multi-layered configurations. The soil covers are intended to 1) provide sufficient pore-gas O2 to facilitate the growth of native boreal forest vegetation and to 2) oxidize methane (CH4) produced in the anaerobic zones of the LOS before being exhausted to the atmosphere as a greenhouse gas.Prior to covering the LOS with soil covers, rates of CO2 efflux from the surface of the LOS to the atmosphere ranged from 0.1-7.1 kg/m2/a. Pore-gas concentrations within the uncovered LOS ranged from 0-18% for oxygen (O2), 3-21% for carbon dioxide (CO2), and 0-12% for CH4. Following placement of soil covers, peak rates of CO2 efflux were 2.3 kg/m2/a from the surface of the soil covers to the atmosphere and 1.8 kg/m2/a from the LOS into the soil covers.Peak rates of O2 influx from the atmosphere through the soil covers was 18 kg/m2/a. Poregasses within the overlying soil covers and uppermost LOS were typically below the threshold that poses a risk to the survivability of reclamation vegetation, >10% O2 and <15% CO2. Poregasses deeper than 2 m within the LOS surpassed this threshold with O2 falling to 0% and CO2 rising to >16%.Rates of CH4 oxidation were quantified in batch soil column experiments for the soil cover materials and LOS in single and multi-layered configurations. Oxidation rates were sensitive to variations in temperature, moisture content, and bulk density. The results of the column experiments indicate that CH4 generated deeper than 2 m within the LOS landform will be partially oxidized in both the soil covers and uppermost LOS horizon.Statistical analyses and finite difference numerical modelling were conducted to guide mine operators regarding practical issues involving the construction of LOS landforms, design of soil cover systems, and management of reclamation sites. Based on these exercises, it appears that the characteristics of the LOS landform are more important to pore-gas dynamics than the design of the soil cover systems.iii ACKNOWLEDGEMENTS

show abstract

Multiple Comparisons among Means

Cited by 3,408 publications

References 2 publications

Geographic isolation and larval dispersal shape seascape genetic patterns differently according to spatial scale

Geographic isolation and larval dispersal shape seascape genetic patterns differently according to spatial scale

A comparison of the effects of text-based instruction versus standards-based instruction in the early years

Pore-gas dynamics in overburden and reclamation soil covers

Contact Info

Product

Resources

About