General/other Flashcards
1
Q
What is the difference between quantitative and qualitative?
A
Quanitative - number
Qualitative - no number (e.g. colour)
2
Q
Why do we take repeat measurements?
A
To calculate a more reliable mean
3
Q
What is the acceptable p value? What does the p value mean?
A
- 0.05 / 5%
- the probability the difference in results is due to chance
- if p<0.05 the difference in results is significant
4
Q
How is the running mean useful for taking a representative sample?
A
- re-calculate the mean whenever a new sample is taken
- sample is representative when the mean doesn’t change / shows less fluctuation
5
Q
What is standard deviation
A
- the spread of data around the mean
6
Q
When is spearmans rank used to determine standard deviation?
A
- to determine if there is a significant
- correlation
- between two variables
7
Q
When is chi squared used to determine standard deviation?
A
- to determine if there is a significant difference between
- the numbers
- in categories
8
Q
When is students T test used to determine standard deviation?
A
- to determine if there is a significant
- difference between
- the means of 2 samples
9
Q
What does ot mean if chi squared/spearmans/T test is above or equal to critical value?
A
- is significant correlation
- reject null hypothesis
- less than 5% probability the correlation is due to chance
10
Q
Why is percentage change in mass used?
A
- allows results to be compared
- as initial masses may have been different
