BIOL2022 L22 nMDS and hypothesis testing

Question 1 of 10

2

Label the steps appropriately (please).

Drag an answer into the correct orange point.

(dis)similarity matrix

nMDS

ANOSIM

SIMPER

ANOVA

PERMANOVA

Explanation

Question 2 of 10

2

Species diversity indexes:
Different diversity indices emphasise different things. Two examples are the following. Which emphasises what?

Drag an answer into the correct orange point.

Emphasises common species

Emphasises rare species

Emphasises non-zero correlations

Emphasises zero-correlations

Emphasises similarities

Emphasises dissimilarities

Explanation

Question 3 of 10

1

In either the Simpson’s index or the Shannon-Weiner index, despite their differences, they both have high index values if:

Select one or more of the following:

Evenness is high
Evenness is low
There are few species
There are many species
None of the above

Explanation

Question 4 of 10

2

Select from the dropdown lists to complete the text.

In a(n) ( nMDS, ANOSIM, PERMANOVA, SIMPER, Bray-Curtis dissimilarity matrix ), a ( Low, High ) stress value means the model is good.

Explanation

Question 5 of 10

1

In a Bray-Curtis dissimilarity matrix, a low number means:

Select one or more of the following:

High dissimilarity
Low dissimilarity
High similarity
Low similarity

Explanation

Question 6 of 10

5

Select from the dropdown lists to complete the text.

ANOSIM is ANalysis Of SIMilarities.
Retains philosophy underpinning ( nMDS, ANOVA, PERMANOVA, SIMPER ), driven by ( Information theory, Hypothesis testing ).
Hands ( Simple, Complex ) designs best.
( Non-parametric, Parametric, Metric, Non-metric ) permutation test combined with randomisation approach to generate significance levels (Monte Carlo tests)
Null – no difference in assemblage composition ( Within, Between ) sites.

Explanation

Question 7 of 10

1

Select from the dropdown list to complete the text.

Steps for ANOSIM:
1. Test statistic – reflects difference among sites to differences within sites. Based on rank similarities in the underlying triangular matrix, generates ( Global R, Stress value, P value, Pearson's correlation ).
2. Recompute [above] under permutations of sample labels. If null is true there should be little change to [above] if labels arbitrarily assigned.
3. Significance value – refer the observed value of [above] to permutation distribution. If it is unlikely (<5%) to fall in this distribution, reject null H

Explanation

Question 8 of 10

1

Which statistical test works with any distance measure that is appropriate to the data, and uses permutations to make it distribution free?

Select one of the following:

PERMANOVA
ANOSIM
ANOVA
SIMPER

Explanation

Question 9 of 10

1

Which statistical test calculates % contribution of each species to the dissimilarities between all pairs of sampling units in different groups and % contribution to similarities between all pairs within groups?

Module 3, Lecture 4 Headings: • Hypothesis testing • nMDS • ANOSIM • SIMPER

BIOL2022 L22 nMDS and hypothesis testing

Question 1 of 10

Label the steps appropriately (please).

Drag an answer into the correct orange point.

Explanation

Question 2 of 10

Species diversity indexes:
Different diversity indices emphasise different things. Two examples are the following. Which emphasises what?

Drag an answer into the correct orange point.

Explanation

Question 3 of 10

In either the Simpson’s index or the Shannon-Weiner index, despite their differences, they both have high index values if:

Select one or more of the following:

Explanation

Question 4 of 10

Select from the dropdown lists to complete the text.

In a(n) ( nMDS, ANOSIM, PERMANOVA, SIMPER, Bray-Curtis dissimilarity matrix ), a ( Low, High ) stress value means the model is good.

Explanation

Question 5 of 10

In a Bray-Curtis dissimilarity matrix, a low number means:

Select one or more of the following:

Explanation

Question 6 of 10

Select from the dropdown lists to complete the text.

Explanation

Question 7 of 10

Select from the dropdown list to complete the text.

Explanation

Question 8 of 10

Which statistical test works with any distance measure that is appropriate to the data, and uses permutations to make it distribution free?

Select one of the following:

Explanation

Question 9 of 10

Which statistical test calculates % contribution of each species to the dissimilarities between all pairs of sampling units in different groups and % contribution to similarities between all pairs within groups?

Select one of the following:

Explanation

Question 10 of 10

Which one is capable of working with more complex designs?

Select one of the following:

Explanation

	Created by Michael Jardine about 6 years ago

Module 3, Lecture 4 Headings: • Hypothesis testing • nMDS • ANOSIM • SIMPER

BIOL2022 L22 nMDS and hypothesis testing

Question 1 of 10

Label the steps appropriately (please).

Drag an answer into the correct orange point.

Explanation

Question 2 of 10

Species diversity indexes: Different diversity indices emphasise different things. Two examples are the following. Which emphasises what?

Drag an answer into the correct orange point.

Explanation

Question 3 of 10

In either the Simpson’s index or the Shannon-Weiner index, despite their differences, they both have high index values if:

Select one or more of the following:

Explanation

Question 4 of 10

Select from the dropdown lists to complete the text.

In a(n) nMDS ANOSIM PERMANOVA SIMPER Bray-Curtis dissimilarity matrix( nMDS, ANOSIM, PERMANOVA, SIMPER, Bray-Curtis dissimilarity matrix ), a Low High( Low, High ) stress value means the model is good.

Explanation

Question 5 of 10

In a Bray-Curtis dissimilarity matrix, a low number means:

Select one or more of the following:

Explanation

Question 6 of 10

Select from the dropdown lists to complete the text.

Explanation

Question 7 of 10

Select from the dropdown list to complete the text.

Explanation

Question 8 of 10

Which statistical test works with any distance measure that is appropriate to the data, and uses permutations to make it distribution free?

Select one of the following:

Explanation

Question 9 of 10

Which statistical test calculates % contribution of each species to the dissimilarities between all pairs of sampling units in different groups and % contribution to similarities between all pairs within groups?

Select one of the following:

Explanation

Question 10 of 10

Which one is capable of working with more complex designs?

Select one of the following:

Explanation

Species diversity indexes:
Different diversity indices emphasise different things. Two examples are the following. Which emphasises what?

In a(n) ( nMDS, ANOSIM, PERMANOVA, SIMPER, Bray-Curtis dissimilarity matrix ), a ( Low, High ) stress value means the model is good.