using statistics in biology Flashcards
What are the 2 types of quantitative variables?
Discrete and continuous
What are discrete variables?
Have variables that are only limited to certain numbers
What are continuous variables?
Contain an unlimited number of values
What is the dependent variable?
The variable we measure, the Y axis
What is the independent variable?
The variable we change , the X axis
What does a positive r value suggest?
Positive correlation
What does a negative R value suggest?
Negative correlation
What is the R value?
A number between -1 and 1 that tells you the type of correlation
What is the R value called?
Correlation coefficient
If you are looking for the strength of the relationship or association between IV and DV, what test would you use?
Correlation coefficient
When would you use the correlation coefficient test?
If you are looking for the strength of the relationship or association between IV and DV
What number can the T value be?
Between -3 and 3
What does a t value of 0 mean?
The means are equal
What does a positive or negative T value mean?
One mean is greater or smaller than the other
When would a T value not be appropriate?
When there is one or more outlier in the data
When would you use the student T test?
When comparing two means/sets of data using one number
When would you use chi-squared?
When comparing observed and expected results
What does it indicate if chi-squared is 0?
There no difference between the observed and the expected result
What does a chi-squared value above zero mean?
There’s some difference between the observed results and the expected results
Why can’t chi-squared tell us if the observed results are higher or lower than expected results?
It doesn’t have any negative values
What sort of data uses chi-squared?
Categorical data- where the IV can only take a limited number of values. Can be non numerical or numerical
What is a hypothesis?
A statement we think is correct and can test
What is the P value?
The probability of observing results by chance
What numbers can a P value be?
Between 0 and 1
What does a P value close to 1 mean?
More likely that the results are a coincidence and by chance
What is the critical P value?
A value that decides if the P value is too high
When is a test result not significant? (P)
When the P value is higher than the critical P value
What is the number of the critical P value?
0.05
