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Ecosystems

Statistical tests in ecology

  • 4 things to know
  • Papers 2 and 3

Overview

Recall questions on when and how to use the t-test and Spearman's rank correlation coefficient, degrees of freedom and critical values, and calculating the mean, median, mode, range and standard deviation of ecological data.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

After ranking both variables for Spearman's rank correlation, what values are calculated for each data pair?

Key term

What conclusion is drawn if the calculated t-value exceeds the critical value?

Key term

After ranking data, what is calculated next for Spearman's correlation?

Key term

What is the purpose of a t-test?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What is the purpose of a t-test?

    Model answer

    To determine whether there is a statistically significant difference between the means of two groups.

  2. 2

    What type of data is required for a t-test?

    Model answer

    Continuous data.

  3. 3

    What assumption about data distribution must be met for a t-test?

    Model answer

    The data must be normally distributed.

  4. 4

    What assumption about variance must be met for a t-test?

    Model answer

    The two groups must have similar variances.

  5. 5

    What must be determined before looking up the critical value for a t-test?

    Model answer

    The degrees of freedom.

  6. 6

    What does Spearman's rank correlation coefficient measure?

    Model answer

    The strength and direction of association between two ranked variables.

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Biological Molecules
Cells, Viruses and Reproduction of Living Things
Classification and Biodiversity
Exchange and Transport

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A base.
nitrogenoussulfurphosphate

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ALag phase shows no increase.
BLog phase shows exponential increase.
CStationary phase shows a plateau.

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Oxidation means loss of electrons or hydrogen.
TrueFalse

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