Sampling and stats

Question 1

What does spearman’s rank determine?

Answer 1

The correlation coefficient- the correlation between species

Question 2

What is standard deviation?

Answer 2

How spread out data is- the greater the spread the greater the standard deviation.

Question 3

Give 4 characteristics of a normal distribution curve.

Answer 3

1. Mean, mode and median are the same
2. Bell shape curve
3. 50% of values are below/above the mean
4. Most values lie closely to the mean value.

Question 4

Define random sampling.

Answer 4

Selecting individuals by chance.

Question 5

Name the three types of non random sampling

Answer 5

1. Opportunistic- uses organisms that are conveniently available
2. Stratified- population are divided into strata based on characteristics and a random sample is taken from each strata based on size
3. Systematic- different areas in an overall habitat are identified and sampled separately

Question 6

What do we use to calculate biodiversity?

Answer 6

Simpson’s index of biodiversity

Question 7

What does Simpsons index range to?

Answer 7

A value in between 0 and 1, where 1 is infinitely biodiverse.

Question 8

How do we find the degree of freedom?

Answer 8

Sum of both samples - number of data sets

Question 9

What does degree of freedom determine?

Answer 9

The critical value that should be used