Measurement & Data Reliability Flashcards
What is the drug analysis process?
1- Select sample 2- extract analyte 3- purify analyte 4- characterisation 5- data validity
How many sig figs to round to in decimals?
3 sig figs
RULES for rounding in + & - ?
Round to the no decimal as the value with the least sig figs
RULES for rounding in division & multiplication?
Round to same no sig figs as the value with least sig figs
Is the 0 before a decimal sig fig?
NO
Is 0 after decimal sig fig?
YES
Which value to write from digital scales
The whole value you see
Which value to write from scaled instruments?
One more figure than you can read with certainty
What is precision?
How close values are to each other
What is accuracy?
How close values are to target
What is an intermediate / random error?
It affects precision more than accuracy
What is determinate / systematic error?
Affects accuracy more than presiding
Can systematic error be improved?
YES
What is a gross error?
Big mistake- outlier
How to calculate precision?
Range
highest - lowest value
Difference between SD and relative SD?
Relative SD removed units- can be compared globally
What can be the origins of systematic errors?
1- instrumental
2- method
3- personal E.g. height
What is the T test used for?
Used to compare 2 averages and calculate confidence intervals when SD not present
Reject null hypothesis if?
If difference in values
