Lab 2 Flashcards
What does a p-value of 0.05 tell us?
Means that the odds of the observed results occurring by chance instead of the variable tested (if the null hypothesis were true) is 5%.
What is p-value?
The odds of the observed results occuring by chance instead of the variable being tested.
How to find degrees of freedom?
The number of environmental conditions (n) minus 1.
What does it mean to have a chi-square value greater than the critical value?
It means that the probability of seeing your observed results if the null were true is less than 0.05, therefore you reject the null hypothesis and support alternate hypothesis.
Reject null??
X2 > critical value
X2 = critical value
X2 < critical value
- Reject null hypothesis.
- Reject null hypothesis.
- fail to reject null hypothesis.
What is the point of replication?
- To demonstrate that results are reproducible.
- To increase you confidence in your results.
What is a hypothesis?
A testable explanation for observed phenomena.
What is a null hypothesis (Ho)?
Study subjects have no preference for conditions of the variable being tested.
What is a alternate hypothesis (Ha)?
Study subjects do have a preference for one condition.
What are abiotic variables?
Nonliving components of environment that affect living creatures.
What are biotic variables?
Living components of environment that affect living creatures.
List 4 biotic variables
- Other animals.
- Plants.
- Bacteria.
- Fungi.
List 5 abiotic variables
- Water.
- Light.
- Food.
- Structure.
- pH.
What is the point of a control? (2)
- The observed results are due only to the variable tested.
- Establish a basis for comparing the observed results.
What are observed values?
What are expected values?
- Total results observed.
- Values that are predicted by the null, even in experimental tests.
