Stats

• We accept any probability greater than 5% as likely to be just chance, but probabilities of 5% or below show us that the data do differ significantly and there must be a cause influencing the outcome
• fill

  A) measurements

  B) frequencies

  C) associations

  D) differences

  E) genetics

  
• Using standard deviation is better than the range as it uses all the observations, and is less affected by the outliers
• look! theres an overlap with the error bars..

  what does this suggest?

  • it's likely due to chance

  
• If P value is less than 0.05, the different is significant and not due to chance
• Some samples may be too many to count so you dilute but some may be countable so don’t dilute
• its the probabilities that are due to chance not the results
• The student’s t-test is a statistical test used to determine if there is a significant difference between the mean values of a particular variable across two populations.
• The conditions for using student's t-test are:

  • The data must be continuous and normally distributed.
  • The variances of the populations should be equal.
  • The samples must be independent of each other.
• null hypothesis for t test:

  This assumes there is no significant difference between the means of the datasets
• If the t statistic is greater than the critical value:

  • Reject the null hypothesis.
  • This suggests that the means are significantly different.

  If the t statistic is less than the critical value:

  • Accept the null hypothesis.
  • This suggests that there is no significant difference between the means, and any difference is just due to chance.
• ± 2 standard deviations from the mean includes over 95% of the data
• do NOT refer to results being due to chance

  • its the differences or associations in their results being due to chance
• The closer the simpsons index is to one, the more diverse the habitat and the greater its ability to cope with changes with the environment

  The lower the index is to zero, it suggests the habitat is more easily damaged by changes in the environment, making it less stable
• spearmans rank gives you a numerical value to tell you the strength and direction of the correlation