DATA QUALITY Flashcards
defined as a deviation from the
absolute value or from the true
average of a large number of results.
Error
can be classified as systematic
error or indeterminate error
Error
Systematic Errors
- also known as the
determinate errors.
errors that are reproducible and can be
discovered and corrected.
Systematic Errors
Systematic Errors Can be further classified into:
Instrumental Error
- Method Error
- Personal Error
failure to calibrate, degradation of
parts in the instrument, power fluctuations, variation in
temperature.
Instrumental Error
rrors due to no ideal physical or
chemical behaviour, completeness and speed of
reaction,
interfering side reactions, sampling problems.
method Errors
occur where measurements require
judgment, result from prejudice, color acuity problems,
negligence to follow proper procedures
Personal errors
are observed by the same
analyst when the successive measurements are
made with the same identical conditions.
Random Errors
Random Errors also known as the
indeterminate errors .
appear as slight variations in successive
measurements due to causes that the analyst
can not control.
Random Errors
A plot of indeterminate error would show a
normal frequency curve
Minimization of Errors
Proper calibration of the glass ware, pipettes,
burettes, weights, balances, instruments, etc.
* By running the blank with the sample. The blank
solution is defined as the solution by omitting
the sample addition. The blank and the sample
solutions are carried simultaneously to obtain
the accurate results.
* By running the parallel determinations.
* Correctly recording and computing data results
is establishing documented
evidence which provides a high degree of
assurance that a specific process, method, system,
activity or equipment consistently produce a
product meeting its predetermined specifications
Validation
pertains to agreement of an
experimental results with true value
Accuracy
is the measure of reproducibility of
data within a series of results.
Precision
In a normal distribution,
__% of the values should
fall within one standard
deviation in either side of
the mean
68%
In a normal distribution,
68% of the values should
fall within ____ standard
deviation in either side of
the mean
ONE
And __% should fall within
two standard deviations of
the mean
95
And 95% should fall within
___ standard deviations of
the mean
2
So, standard deviation
should be a ____
percentage of the mean.
SMALL
measure of central tendency
Mean
difference between largest/smallest
observations in a set of data
Range
measures the difference of the
actual values with the mean value
Average Deviation