Jove
Visualize
Contact Us

Related Concept Videos

McNemar's Test01:23

McNemar's Test

929
McNemar's Test is a nonparametric statistical test used to determine if there is a significant difference in proportions between two related groups when the outcome is binary (e.g., yes/no, success/failure). It is beneficial when we have paired data, such as pre-test/post-test designs, where the same subjects are measured under two different conditions. The test is named after the statistician Quinn McNemar, who introduced it in 1947. It is commonly used in situations where subjects are...
929
Randomized Experiments01:13

Randomized Experiments

9.1K
The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias.
Simple randomization
Simple...
9.1K
Wald-Wolfowitz Runs Test II01:17

Wald-Wolfowitz Runs Test II

588
The Wald-Wolfowitz runs test, commonly referred to as the runs test, is a nonparametric test used to assess the randomness of ordered data. The test evaluates the number of runs, which are consecutive sequences of similar elements within the data. If the number of runs is significantly higher or lower than expected, the data is considered non-random, indicating a detectable pattern or structure.
For binary data, runs are identified using symbols such as + and −, or equivalently, 1s and 0s. In...
588
Test for Homogeneity01:23

Test for Homogeneity

2.5K
The goodness–of–fit test can be used to decide whether a population fits a given distribution, but it will not suffice to decide whether two populations follow the same unknown distribution. A different test, called the test for homogeneity, can be used to conclude whether two populations have the same distribution. To calculate the test statistic for a test for homogeneity, follow the same procedure as with the test of independence. The hypotheses for the test for homogeneity can...
2.5K
Wald-Wolfowitz Runs Test I01:17

Wald-Wolfowitz Runs Test I

987
The Wald-Wolfowitz test, also known as the runs test, is a nonparametric statistical test used to assess the randomness of a sequence of two different types of elements (e.g., positive/negative values, successes/failures). It examines whether the order of the elements in a sequence is random or if there is a pattern or trend present. This nonparametric test applies to any ordered data despite the population and sample data distribution, even if a higher sample size is available.
The test works...
987
One-Way ANOVA: Unequal Sample Sizes01:15

One-Way ANOVA: Unequal Sample Sizes

6.8K
One-way ANOVA can be performed on three or more samples of unequal sizes. However, calculations get complicated when sample sizes are not always the same. So, while performing ANOVA with unequal samples size, the following equation is used:
6.8K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The EU Nature Restoration Regulation offers new opportunities for resilient forests and sustainable forestry.

Ambio·2025
Same author

Where to restore: Connectivity forest for spatial prioritization in forest landscape restoration.

iScience·2025
Same author

To what extent does surrounding landscape explain stand-level occurrence of conservation-relevant species in fragmented boreal and hemi-boreal forest?-a systematic review protocol.

Environmental evidence·2024
Same author

To what extent does surrounding landscape explain stand-level occurrence of conservation-relevant species in fragmented boreal and hemi-boreal forest? - a systematic review.

Environmental evidence·2024
Same author

Multiple drivers of large-scale lichen decline in boreal forest canopies.

Global change biology·2022
Same author

Landscape trajectory of natural boreal forest loss as an impediment to green infrastructure.

Conservation biology : the journal of the Society for Conservation Biology·2018
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Video

Updated: Mar 1, 2026

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity
08:16

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Published on: March 13, 2014

19.5K

A null model for randomization tests of nestedness in species assemblages.

Bengt Gunnar Jonsson1

  • 1Department of Ecology and Environmental Science, Umeå University, 901 87, Umeå, Sweden.

Oecologia
|May 27, 2017
PubMed
Summary

This study challenges current methods for analyzing species nestedness, proposing a new randomization approach. The findings suggest focusing on species frequency for accurate nestedness detection, irrespective of site characteristics.

Keywords:
BiogeographyBootstrappingCommunity structureNested subsets

More Related Videos

Nest Building Behavior as an Early Indicator of Behavioral Deficits in Mice
06:11

Nest Building Behavior as an Early Indicator of Behavioral Deficits in Mice

Published on: October 19, 2019

21.4K
Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

3.8K

Related Experiment Videos

Last Updated: Mar 1, 2026

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity
08:16

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Published on: March 13, 2014

19.5K
Nest Building Behavior as an Early Indicator of Behavioral Deficits in Mice
06:11

Nest Building Behavior as an Early Indicator of Behavioral Deficits in Mice

Published on: October 19, 2019

21.4K
Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

3.8K

Area of Science:

  • Ecology
  • Community Ecology
  • Biodiversity Research

Background:

  • Nested subset analysis is a key method for understanding species assemblage order.
  • Recent studies question the validity of existing randomization procedures for nestedness testing.
  • Current methods often control for species richness per site and species frequencies.

Purpose of the Study:

  • To question assumptions in current randomization methods for nestedness analysis.
  • To propose a revised null model for testing species nestedness.
  • To differentiate nestedness testing from other ecological questions like species co-occurrence.

Main Methods:

  • Proposes a new randomization procedure for species-by-site matrices.
  • Suggests randomizing matrices based solely on species frequency as occurrence probability.
  • Advocates for treating all sites as equal when testing for nestedness.

Main Results:

  • The proposed method is computationally simple.
  • It allows for testing nestedness and comparing species richness range to random expectations.
  • This approach provides a statistically robust test for nestedness.

Conclusions:

  • The choice of null model is critical and depends on the research question.
  • The proposed method is suitable for nestedness analysis.
  • For other analyses, such as pairwise co-occurrence, controlling for site richness is appropriate.