On-line statistics

Key for the selection of a test for diversity indices

Are your data to be selected at random from the population you are studying?

Does every data point available have the same chance of being selected and are they independent from each other?

These two points should be set in stone! If not the test results will be biased in one form or another and the conclusions that you make may be completely irrelevant. For example, by sampling a river bed with a net of mesh size 0.5mm, for animals of between 0.25 and 1.3mm, you would be including bias in your sampling by excluding those individuals smaller than 0.5mm.

Use the key by answering the questions in the most relevant way. It is advised that you double check through a good reference guide.

1. Do you wish to calculate diversity indices or assess the similarity of two or more samples?

Calculate diversity indices........see Diversity Indices page

Assess similarities...................go to 2

2. How are your data organised?

Species are present or absent......Søerensen's Quotient

Presence/absence and abundance...Peterson's Homogeneity Index

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Descriptive Stats

Diversity Indices

Comparisons

Correlations

Regression