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Table 1.

Summary of statistics described in the text.

Type of AnalysisDescription/ApplicationExampleConsiderations
Total abundance Number of arthropods in a collected sample 75 arthropods in a trap Are students limited in how many arthropods they collect?
Number of colonies cultured from an arthropod 200 colonies on a plate Colonies can grow together, or form lawns; students might estimate rather than count
Richness Number of morphologically distinguishable arthropods 6 species of crickets Adults and immatures look different; similar-looking species
Number of morphologically distinguishable colony types 4 different types of colonies on a plate Colonies might look similar; falsely interpreted Gram stains or cell shapes
Shannon index (H’) Index of diversity of a sample; actual index can vary depending on the log base used H’ = 1.5 (colonies on a plate) Easily calculated with Excel formulas; higher H’ means more diversity
Simpson index (D) Index of diversity of a sample D = 0.7 (colonies on a plate) Easily calculated with Excel formulas; higher D means less diversity
Jaccard index (Cj) Index of similarity among a set of samples Cj = 0.7 (two plates have most colony types in common) Some equations for this can be intimidating!
Fisher’s Exact test (P value) Compares two outcomes between two groups (e.g., presence/absence of a microbe cultured from crickets vs. spiders) P = 0.002 (microbe is significantly less likely to be present in one type of arthropod) Only returns a P value; uses factorials; might be intimidating
Type of AnalysisDescription/ApplicationExampleConsiderations
Total abundance Number of arthropods in a collected sample 75 arthropods in a trap Are students limited in how many arthropods they collect?
Number of colonies cultured from an arthropod 200 colonies on a plate Colonies can grow together, or form lawns; students might estimate rather than count
Richness Number of morphologically distinguishable arthropods 6 species of crickets Adults and immatures look different; similar-looking species
Number of morphologically distinguishable colony types 4 different types of colonies on a plate Colonies might look similar; falsely interpreted Gram stains or cell shapes
Shannon index (H’) Index of diversity of a sample; actual index can vary depending on the log base used H’ = 1.5 (colonies on a plate) Easily calculated with Excel formulas; higher H’ means more diversity
Simpson index (D) Index of diversity of a sample D = 0.7 (colonies on a plate) Easily calculated with Excel formulas; higher D means less diversity
Jaccard index (Cj) Index of similarity among a set of samples Cj = 0.7 (two plates have most colony types in common) Some equations for this can be intimidating!
Fisher’s Exact test (P value) Compares two outcomes between two groups (e.g., presence/absence of a microbe cultured from crickets vs. spiders) P = 0.002 (microbe is significantly less likely to be present in one type of arthropod) Only returns a P value; uses factorials; might be intimidating
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