Statistics Flashcards
How do you know to use a x2 test (chi)?
Involves finding the number of individuals in particular categories
How do you know to use the t test?
Investigation involves looking for differences between mean values
Investigation involves taking measurements
How do you know if it’s spearman’s rank?
Involves taking measurements
Looks at associations between different measurements from the same sample
What is a null hypothesis?
What are you don’t think will happen
What does p=0.05 mean
There’s a 5% probability results are due to chance
When do you accept the null hypothesis?
P>0.05
More than 5% probability results due to chance we accept the null hypothesis and results on significant
When do you reject the null hypothesis?
P<0.05
Less than 5% probability resort due to chance
We reject the null hypothesis
Results are significant
Describe the chi squared test
FaceTime Kate in the value of X squared from the equation (equation in notes)
Describe critical value
Is the borderline between accepting and rejecting our null hypothesis?
What is the calculation for degrees of freedom?
Number of categories minus one
If the chi squared value is small, what happens to the null hypothesis?
There’s a small difference between the observed and expected value so the normal hypothesis is accepted
If thechi squared value is large, what happens to the null hypothesis?
Huge difference between observed and expected so the no hypothesis is rejected
How do you calculate standard deviation?
Set up, six stats equals Com 2, input data equals after each data port, AC, option, 2, scroll down, SX is standard deviation
How are errors bars calculated?
By plotting the highest value in the lowest value they show the extremes of data
What can error bars show?
How spread the data are around the mean
How accurate the mean value represents the data
If there are overlap, it shows that there is no significant difference between the two data set
