Statistical Analysis Flashcards
Beginning unit on how to analyze biological statistics
What is an average?
The sum of all the numbers in each cohort divided by the number of members in each cohort
What is standard deviation?
a measure that is used to describe how tightly your data is clustered around the average
What does standard deviation tell us?
Reproducibility, precision, reliability of the data collection measures
Low precision = _______ std dev
high
High precision = _____ std dev
low
Consequence of low precision
The experiment might have to be redone.
How is standard deviation represented on a graph?
Error bars, which are required whenever averages are displayed
Equation for determinng the level of standard deviation
((std dev/avg) x 100)
What value of level of standard deviation is too high?
at 20% of the average
T-test
a statistical test used to evaluate the size and significance of the difference between two means
What does t-test tell us
how different the averages of the two sets really are
What value does Excel give us for the t-test?
a p (probability) value
If p is less than or equal to 0.05…
the averages are different from each other (greater than 95% confident)
If p is greater than or equal to 0.05
the averages are the same
If p is between 0.05 and 0.1
it suggests a potential difference, and should be repeated with larger sample sizes for each cohort.
