BIOL2022 L07 Three cardinal sins: Non-independence, Confounding, Pseudoreplication
Description
Module 1, Lecture 7
By the end of this lecture you should understand:
- Why independence is important
- Lack of independence causes pseudoreplication
- Lack of independence causes confounding
- Independence is the single most important thing you can use to do good experiments (both manipulative and mensurative
An bloody uprising of the oppressed population to overthrow the proverbial [or literal] shackles of their masters!
Question 2
Question
Pseudoreplication = “The use of inferential statistics to test for treatment effects with data from experiments where either TREATMENTS ARE NOT REPLICATED (though samples may be), or REPLICATES ARE NOT STATISTICALLY INDEPENDENT.”
True or false: An experiment on a sediment core which has been stratified into 5 sub-samples (n=5) avoids pseudoreplication as measurement bias has eliminated.
Answer
True
False
Question 3
Question
Pseudoreplication = “The use of inferential statistics to test for treatment effects with data from experiments where either TREATMENTS ARE NOT REPLICATED (though samples may be), or REPLICATES ARE NOT STATISTICALLY INDEPENDENT.”
True or false: An experiment on a sediment core which has been split into 5 sub-samples falls into pseudoreplication as only one sediment core (n=1) is being used.
Answer
True
False
Question 4
Question
Experiment: A drug trial using mice is investigating whether drug [x] has an effect on heart rate.
A positive effect is found, but this could be because the injection itself causes tachycardia.
This in an example of: