Representative/random
Large samples can be just as biased as small samples, depending upon how they are selected. For example, you want to do a survey to see how popular the President is, but you only interview men, refusing to interview women. No matter how many men you interview, this bias still exists. A sample of a million men is still biased if you have excluded women. (Although the data are still significant as long as you recognize that the bias exists.)
Reagent Blank : Take reagent and add deionised water (in place of sample to be tested). Now measure the OD at specific wavelength --> this OD is your reagent blank. Substract this OD from your test result (with sample) to avoid any false +ve effect due to colour of reagents itself.Sample Blank : Take sample and measure the OD without adding reagents --> this OD is your sample blank. Substract this OD from your test result to avoid any false +ve effect due to colour and turbidity of sample itself. As it is the fact that colour and turbidity of each sample would vary from one to another.So now it is clear that Reagent blank is used to avoid bias due to colour of reagents and Sample blank is used to avoid bias due to sample itself.
a sample is a sample sized piece given... a sample size is the amount given in one sample
The larger your sample size, the less variance there will be. For instance, your information is going to be much more substantial if you took 1000 samples over 10 samples.
A representative sample is one where the statistics of the sample are the same as the statistics for the parent population.
bias
it is non-random and prone to bias unrepresentative of target population
The standard deviation. There are many, and it's easy to construct one. The mean of a sample from a normal population is an unbiased estimator of the population mean. Let me call the sample mean xbar. If the sample size is n then n * xbar / ( n + 1 ) is a biased estimator of the mean with the property that its bias becomes smaller as the sample size rises.
Large samples can be just as biased as small samples, depending upon how they are selected. For example, you want to do a survey to see how popular the President is, but you only interview men, refusing to interview women. No matter how many men you interview, this bias still exists. A sample of a million men is still biased if you have excluded women. (Although the data are still significant as long as you recognize that the bias exists.)
What? Bias is a one sided opinion
Bias
Reagent Blank : Take reagent and add deionised water (in place of sample to be tested). Now measure the OD at specific wavelength --> this OD is your reagent blank. Substract this OD from your test result (with sample) to avoid any false +ve effect due to colour of reagents itself.Sample Blank : Take sample and measure the OD without adding reagents --> this OD is your sample blank. Substract this OD from your test result to avoid any false +ve effect due to colour and turbidity of sample itself. As it is the fact that colour and turbidity of each sample would vary from one to another.So now it is clear that Reagent blank is used to avoid bias due to colour of reagents and Sample blank is used to avoid bias due to sample itself.
To ensure validity of test, one should prepare a table of specification to describe the topics to be covered in a test and the number of items or points which will be associated with each topic and to identify the achievement domains being measured and to ensure that a fair and representative sample of questions appear on the test.
The velocity of light in a liquid sample is always less than the light in air The velocity of light in a liquid sample is always less than the light in air
bias - favouring one point of view.
This is the diagram that shows where everything is going. You will need to make one up for your business to ensure accuracy.
No, bias is from people siding with one side on purpose.