Linked Questions

14
votes
3answers
87k views

Why does the standard deviation not decrease when I do more measurements? [duplicate]

I made 100 measurements of a certain quantity, calculated mean and standard deviation (with MySQL), and got mean=0.58, SD=0.34. The std seemed too high relative to the mean, so I made 1000 ...
4
votes
4answers
17k views

Standard Error vs. Standard Deviation of Sample Mean [duplicate]

I'm having difficulty figuring out the difference between (typically referred to as S.E): A. The Standard Error And B. The Standard Deviation of the Sample Mean (typically referred to as s) Are ...
-2
votes
2answers
4k views

Under what circomstances the sample standard error is likely to equal population standard deviation? [duplicate]

Does it make a difference if we assume that sample standard error for a very large sample-size equals population standatd deviation for a target population ?
3
votes
1answer
373 views

Why do we rely on the standard error? [duplicate]

Possible Duplicate: Difference between standard error and standard deviation I cannot come to terms with the fact that the standard error is used to describe the accuracy of a point estimate. For ...
-3
votes
1answer
127 views

What is the standard error of the mean? [duplicate]

I don't know anything about this topic. Can you explain and describe standard error of the mean?
1
vote
0answers
71 views

Plain words (non-mathematical) explanation of the difference between Confidence Intervals, Standard Error of the Mean, and Standard Deviation? [duplicate]

As the question states, I'm interested in the difference between CIs, SEM, and SD, explained in plain words (so as to be able to communicate it to people without maths/stats background). My current ...
0
votes
0answers
52 views

About Standard Error of the Mean [duplicate]

Standard Error of the Mean I do not clearly understand about 'Standard Error of the Mean'? I tried understanding about it but I failed. How do you calculate in order to retrieve 'Standard Error of ...
0
votes
1answer
31 views

Puzzling contradiction in introductory textbook regarding standard deviation and sample size [duplicate]

I am reading Facts From Figures by MJ Moroney. In one part of the textbook (chapter 10, pages 136-137) he writes of samples taken from a population with a normal distribution, that their "standard ...
159
votes
3answers
188k views

What is the difference between a consistent estimator and an unbiased estimator?

What is the difference between a consistent estimator and an unbiased estimator? The precise technical definitions of these terms are fairly complicated, and it's difficult to get an intuitive feel ...
27
votes
1answer
81k views

Converting standard error to standard deviation?

Is it sensible to convert standard error to standard deviation? And if so, is this formula appropriate? $$SE = \frac{SD}{\sqrt{N}}$$
5
votes
2answers
9k views

ARMA - coefficient interpretation

I would like to interpret my ARMA model. I would like to tell about all those numbers as much as possible. I tried to study it but there as still some issues I am not sure about. I will start by ...
2
votes
2answers
7k views

When do we use S.E.M. and when do we use S.D.?

Put simply, the standard error of the sample mean is an estimate of how far the sample mean is likely to be from the population mean, whereas the standard deviation of the sample is the degree to ...
1
vote
1answer
7k views

Confidence intervals without sample size

I'm calculating confidence intervals for data that I generated myself, so the sample size is very large (about 30,000). Using the standard formula where the sample size is taken into account, my "...
5
votes
1answer
3k views

Usage of Plus-minus sign

I have a question concerning statistical conventions. I want to report the classification rate of a 3-fold cross validated machine learning experiment. Of course I report the mean and some measure of ...
2
votes
1answer
5k views

Standard Error for Sum

I am designing an algorithm for a stratified sampling on a population and then I want to find out what is the error bound for 95% confidence interval, for different sample statistic such as sum of the ...

15 30 50 per page