
	Where results make sense

Topic: Sample error

	Sampling Error
		Sampling error of a mean value estimated from a sample is equal to the estimated standard deviation of the variable divided by the square root of the sample size.
		If we have computed a sample mean of household size of 2.6 and we determine that the sampling error on this value 0.01, then this means that we have 95 percent confidence that the estimated value of 2.6 is within 0.02 of the population value.
		Because sampling error is a function of the method used to draw the sample, extracting subsets of the data may have the effect of invalidating the error estimation, if the subsets are drawn in such a way as to introduce a substantial non-random element into the subset.
	npts.ornl.gov /npts/1995/courseware/Useable_Nav3_18_27.html (1090 words)

	[No title] (Site not responding. Last check: 2007-10-03)
		Sampling error may be interpreted as a range or interval of percentage values around the sample estimate within which the true population percentage may with confidence be expected to lie.
		In this type of application of the table, the "percent in error" indicators of quality level represent the 4-4 August 22, 1966 M20-2 population percentage to be estimated, and the control limits represent limits of sampling error to be associated with the expected sample estimate.
		Although this sample percent is in excess of 15%, the "standard," it is not in excess of 22.58%, the upper limit of the range within which sample percents may be expected to fall when samples of 200 units are drawn from a process in which the true underlying proportion is 15%.
	www.warms.vba.va.gov /admin20/m20_2/ch04.doc (5537 words)

	eBMJ -- Statistics at Square One: The t tests
		It is therefore unlikely that the sample with mean 3.2 came from the population with mean 2.5, and we may conclude that the sample mean is, at least statistically, unusually high.
		Sample 1 contains 15 patients who are given treatment A, and sample 2 contains 12 patients who are given treatment B. The transit times of food through the gut are measured by a standard technique with marked pellets and the results are recorded, in order of increasing time, in Table 7.1.
		A random sample of patients with disease of comparable severity and aged 20-44 is chosen and the two treatments administered on two successive occasions, the order of the treatments also being determined from the table of random numbers.
	www.bmj.com /collections/statsbk/7.shtml (3412 words)

	Salford Systems (Site not responding. Last check: 2007-10-03)
		Error rates from each of the V cross- validation trees are combined and mapped to the nodes in the original maximal tree.
		If you had used a test sample instead of cross validation, you would have been presented with "test sample relative cost." The resubstitution relative cost depicts the error rate that would be estimated had you used a copy of the learn sample as your test sample.
		The cross validation error rate is derived from one cross-validation procedure, whereas a test sample error rate is derived from one test sample.
	www.salford-systems.com /carttechfaq18.php (1010 words)

	Sample Error Messages
		ERROR X0Y55: The number of rows in the base table does not match the number of rows in at least 1 of the indexes on the table.
		Error when trying to retrieve row location '(1,6)' from the table.
		ERROR X0X61: The values for column 'C10' in index 'T1_C10' and table 'APP.T1' do not match for row location (1,7).
	db.apache.org /derby/manuals/admin/hubprnt40.html (202 words)

	Methodology
		In most research projects, the sample size is determined by the level of acceptable error.
		While the first two sources of error are independent of the sample size, the third source of error is directly correlated with it.
		Therefore all surveys that draw a sample of people from the total population are subject to sampling error.
	www.bridgeratings.com /method_sample.htm (196 words)

	eBMJ -- Statistics at Square One: Differences between means: type I and type II errors and power (Site not responding. Last check: 2007-10-03)
		We saw in Chapter 3 that the mean of a sample has a standard error, and a mean that departs by more than twice its standard error from the population mean would be expected by chance only in about 5% of samples.
		The sample mean may happen to be identical with the population mean but it more probably lies somewhere above or below the population mean, and there is a 95% chance that it is within 1.96 standard errors of it.
		If the sample comes from the same population its mean will also have a 95% chance of lying within 196 standard errors of the population mean but if we do not know the population mean we have only the means of our samples to guide us.
	www.bmj.com /collections/statsbk/5.shtml (2015 words)

	A note on sampling error
		Margin of sampling error for the overall results is plus or minus 4 percentage points and plus or minus 6 percentage points for the white and fl subsamples." Chicago Sun-Times October 8, 1995, p.
		Note however, that all of the sampling errors reported and calculated in the above table are based on a critical assumpltion that is in all likelihood known to be false.
		In general a poll's response rate is a far better indicator of the reliability of the poll than the sampling error measure that is reported.
	lilt.ilstu.edu /gmklass/pos138/datadisplay/sampling.htm (1111 words)

	California Survey Research Services
		In most research projects, the number of people that must be sampled is determined by the amount of error that is willing to be tolerated.
		The first two sources of error are independent of the number of people in the sample.
		The third source of error is very much dependent on the number of people in the sample.
	www.calsurvey.com /resources.htm (270 words)

	Sampling Design Issues
		Sampling frame is the computer file of items that could be sampled, such as accounts payable ledger or sales register.
		Sample leverage is the amount the projected total error will change as the result of an error in one sample item.
		When very few errors exist in a stratum, the estimated variance and mean have a higher risk they do not represent the true variance and mean in the population.
	www.willyancey.com /sampling-design.htm (1253 words)

	Out-of -sample tests of forecasting accuracy: an analysis and review
		Unless the sample size is small, these effects may be more substantial than the changes that arise from recalibrating the regression coefficients.
		He then compared forecast errors for (a) years in which cyclical turning points occurred and (b) years in which the overall direction of the economy did not change.
		Error statistics that are calculated by applying every method to every time series may give misleading results.
	www.forecastingeducation.com /archive/2000/ijfoct-outofsampletests.htm (6872 words)

	baudline solution - sample rate stability
		The output error is less than 5 PPM for all of the sample rates, and it is less than half that for the majority of them.
		For the sample rates { 11025, 22050, 44100 } the i/o PPM error is { 6.135, 9, 23 } which is an unusual progression.
		The 48000 to 44100 sample rate conversion is a difficult ratio for polyphase filter generation but this is an unrelated problem since it doesn't explain why the ADC and the DAC clocks would need to be different.
	www.baudline.com /solutions/sample_rate (2600 words)

	Questionnaire Design and Surveys Sampling
		A pilot or preliminary sample must be drawn from the population and the statistics computed from this sample are used in determination of the sample size.
		Observations used in the pilot sample may be counted as part of the final sample, so that the computed sample size minus the pilot sample size is the number of observations needed to satisfy the total sample size requirement.
		Note, incidentally, that as long as the sample is a small fraction of the total population, the actual size of the population is entirely irrelevant for the purposes of this calculation.
	home.ubalt.edu /ntsbarsh/stat-data/Surveys.htm (7163 words)

	(Cover Story: Packaging) Sample Size Selection Using a Margin of Error Approach (MDDI archive, Oct 06)
		Important factors to be considered when determining an appropriate sample size include the possible risks associated with a given failure, the likelihood of the failure, relevant consequences associated with the failure, and any relevant sterile barrier system history.
		If the sample were pulled appropriately (i.e., throughout the run), and the process were in control, some reasonable assumptions can be made about the portion of the population that was not sampled.
		The sample mean should be tested using any one of a number of tests to ensure that the normal probability assumption has been met before proceeding with this approach.
	www.devicelink.com /mddi/archive/06/10/002.html (3187 words)

	SAMPLE HANDLING STRATEGIES FOR ACCURATE LEAD-IN-SOIL MEASUREMENTS - Title
		In the case of a sampling error of 14.1% and a subsampling error of 14.3%, the total error is 20.1%.
		While this analytical error is far worse than that of laboratory atomic spectrometry, the overall error of the methods may be fairly similar after taking into account sampling, sample handling, and sample preparation.
		To assess field based error (that is, error caused by sampling and sample handling), the sampling program should include field duplicates and replicates taken as early as possible in the sampling process.
	www.niton.com /shef01.html (6560 words)

	Sample Size, Error Rate, Minitab
		Since the area you are most concerned about is whether the error rate at the branch is representative of all branches, you might want to start at the data from the distribution center.
		Gather error rate and volume data for each of the branches and use a Chi Squared Contengency Table to test the hypothesis that the error rate is the same across the sampled branches.
		As for sample size here, one of the limitations of the contingency table is that you have to have at least 5 errors from each branch so you will need to ensure that your samples are high enough from each branch to yield at least 5 errors.
	www.isixsigma.com /forum/showthread.asp?messageID=58100 (1532 words)

	SPSS Complex Samples - Sampling Error, Stratified Sample, Random Sampling, Cluster Sample, Multistage Sampling (Site not responding. Last check: 2007-10-03)
		If you're working with complex sample designs, such as stratified, clustered or multistage sampling, you need specialized statistical techniques to account for the sample design and its associated standard errors.
		Stratified sampling—increase the precision of your sample or ensure a representative sample from key groups by choosing to sample within subgroups of the survey population.
		Multistage sampling—select an initial or first-stage sample based on groups of elements in your population; then create a second-stage sample by drawing a sub-sample from each selected unit in the first-stage sample.
	www.spss.com /nz/complex_samples (625 words)

	DSS Research: Sample Error Calculator
		The DSS tool calculates the finite population correction factor when appropriate to adjust the sampling error upward to account for measuring a significant portion of the population universe.
		Enter the size of the sample drawn from the population being studied.
		If the total population you are studying is small or your sample makes up at least 5% of the entire population, entering the population here will reduce the sampling error calculated.
	www.dssresearch.com /toolkit/secalc/error.asp (202 words)

	DOC: Code Sample Error in Documentation for RowTop Method
		When you execute the sample code, an "Expected End of Statement" error occurs and the following line of code is highlighted:
		This error occurs because the RowValue argument for the RowTop method is not enclosed in parentheses.
		This documentation error was corrected in Visual Studio 97 Service Pack 3.
	support.microsoft.com /kb/150469 (173 words)

	[No title]
		Nearly 60,000 sample ballots sent to area voters inadvertently omitted the Republican Central Committee District 4 contest featuring 12 candidates running for nine committee seats, county registrar of voters Jill LaVine said.
		After the error was discovered Thursday, all the candidates for the affected contest were personally contacted and alerted to the error, LaVine said.
		In light of the error, LaVine said officials also checked all absentee ballots as well as ballots available at polling places June 6 and found no errors.
	www.news10.net /storyfull2.aspx?storyid=17302 (308 words)

	Estimating misclassification error with small samples via bootstrap cross-validation -- Fu et al. 21 (9): 1979 -- ...
		sample size n is small, the data in S are sparse.
		3 Densities of conditional misclassification errors in relative scale estimated by different methods from 1000 runs of generating random sample S of size n from the breast cancer prognosis data and testing on the remaining data.
		Efron, B. (1983) Estimating the error rate of a prediction rule: improvement on cross-validation.
	bioinformatics.oxfordjournals.org /cgi/content/full/21/9/1979 (3358 words)

	Sample Size, Error Rate, Minitab
		Sample Size, Error Rate, Minitab by Robin Sarac on Thursday, 28th October 2004
		Re: Sample Size, Error Rate, Minitab by Bob J on Friday, 29th October 2004
		Re: Sample Size, Error Rate, Minitab by sqe on Friday, 29th October 2004
	www.isixsigma.com /forum/showmessage.asp?messageID=58100 (595 words)

	Windows SDK WPF Sample Error..
		Channel 9 Forums » The Coffeehouse » Windows SDK WPF Sample Error..
		I was hoping for better samples than this, especially with the animation.
		I've blogged about the issue with samples here.
	channel9.msdn.com /ShowPost.aspx?PostID=138698 (128 words)

	xml sample compilation error - dBforums
		If you would prefer not to see any double-underlined words and corresponding advertisements, please click here.
		I am using ASE 12.5 eval copy in WINNT 4.0 I have installed java and when i am trying to workout XML in sample given in sybase java manual i am getting the following error
		can anybody help me to solve the problem pls also help with some sample code to transfer data from sql to xml and viceversa.or a reference to a web site of sample will be helpful
	www.dbforums.com /t587454.html (252 words)

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