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Topic: Interval estimation


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In the News (Sat 25 Oct 14)

  
  Parameter estimation   (Site not responding. Last check: 2007-10-13)
The distinction between these two types of estimation is moot when the parameters in the mathematical expression of the family are properties of the distribution, as it is the case for example of the normal distribution (mean and variance).
In a binormal distribution, the empirical correlation coefficient is a biased estimator of the coefficient of correlation of the distribution.
An estimator is a statistic whose properties as a random variable let us expect that its value for the sample at hand (the estimate) is close to the true value of the parameter that is being estimated.
www.aiaccess.net /English/Glossaries/GlosMod/e_gm_estimation.htm   (2380 words)

  
 Chapter 7: Confidence Interval Estimation   (Site not responding. Last check: 2007-10-13)
When a sample is selected and a confidence interval estimate developed, we usually can't determine whether the interval correctly estimates the population parameter.
When developing a confidence interval estimate for the mean, if s is known, we use the normal distribution, and if s is unknown we use the t distribution.
The number of degrees of freedom in a confidence interval estimate of the mean with s unknown is the sample size n minus one.
myphliputil.pearsoncmg.com /student/levine/chap7.html   (291 words)

  
 BioMed Central | Full text | Interval estimation of genetic susceptibility for retrospective case-control studies
The prevalence of the hypersensitivity reaction is estimated to be between 0.03 and 0.06 [16].
The estimate of φ using (1) and the midrange w (that is equal to 0.045) is 0.382.
Haldane JBS: The estimation and significance of the logarithm of a ratio of frequencies.
www.biomedcentral.com /1471-2156/5/9   (4759 words)

  
 ED230A Interval Estimation
Estimating the population mean by using the sample mean is called point estimation.
A confidence interval for a parameter is an interval computed from sample data containing the true value of the parameter with a certain level of confidence.
With a 95% confidence interval for a sample mean, 95% of all sample of the same size will contain the true population mean.
www.gseis.ucla.edu /courses/ed230a2/notes2/interval.html   (685 words)

  
 Confidence Intervals
Use the value of the sample statistic to estimate the value of the population parameter in question.
whose value is used to estimate the true value of a population parameter.
Choose a statistic (usually this is one of the parameter-estimators we use to give point-estimates for the population parameter in question) and compute its value from the observed sample data.
www.marin.cc.ca.us /~npsomas/Confidence_Intervals.htm   (544 words)

  
 Research Methods - Research Error in AllPsych Online
In point estimation, the value of a sample statistic or achieved score is used as a best guess or quick estimate of the population statistic or true score.
The major concern of point estimation is the lack of concern for error; the achieved score is assumed to be the true score.
Interval estimation goes a step further and assumes that some level of error has occurred in the achieved score, which is almost always the case.
allpsych.com /researchmethods/researcherror.html   (886 words)

  
 Chapter 5: Sampling Distributions and Interval Estimation
Interval Estimation: Part of being honest with statistics is to admit you could be wrong, then to estimate the likelihood you're wrong, and to estimate how far wrong you most likely are.
Interval Estimation Using Estimated Standard Error of the Mean: All of the examples thus far deal with populations whose standard deviation is known; but, in real life, we know this is often not the case.
Interval Estimation When N is Small AND the Population Standard Deviation is Unknown: This can happen, and it involves remembering to deal with both problems, one at a time.
www.angelfire.com /sd/ma243/enotes5.html   (6283 words)

  
 ESTIMATION
The purpose of estimation is to estimate an unknown population parameter based on information gathered from a sample.
Point Estimation is a procedure in which a precise value for the population parameter is calculated.
Interval Estimation is a procedure in which a range of values, called a confidence interval, is calculated.
otel.uis.edu /yoder/est_h.htm   (581 words)

  
 Interval estimation of the attributable risk in case-control studies with matched pairs -- Lui 55 (12): 885 -- Journal ...
However, the research on interval estimation of the AR under this design is limited.
This paper demonstrates that the interval estimator derived from a quadratic equation developed here is generally preferable to the one based on Wald's statistic.
Interval estimation of the attributable risk for multiple exposure levels in case-control studies.
jech.bmjjournals.com /cgi/content/full/55/12/885   (2610 words)

  
 Estimation Sg
in which it is estimated that the parameter is contained.
An estimator is said to be unbiased when the “long run” average of the estimator equals the
The discussion of estimation procedures has so far involved only instances where the parameter being estimated is a population mean, With slight modifications, however, the procedures and their interpretations are equally valid when estimating other population parameters, such as p.
www.wcu.edu /cob/faculty/schreib/mgt235/topics/Estimation/sg-004.htm   (1977 words)

  
 Basics of parameter estimation
From using the normal approximation of the sampling distribution of the sample proportion, we know that the sample proportion will be within 1 SE of the population proportion about 68% of the time (i.e., for about 68% of samples of size n).
Bigger interval is less likely to miss the parameter, but it doesn't pin it down as tightly.
Smaller interval pins down the most plausible/consistent values of the parameter more precisely, but is more likely to miss covering the parameter.
www.sscnet.ucla.edu /ssc/labs/brenner/econ40/estimation.htm   (1345 words)

  
 bp_berenson_bbs_9|Confidence Interval Estimation|Multiple Choice
It is possible to construct a 100% confidence interval estimate for the population mean.
When estimating the population mean with a small sample, the t distribution may be used with ______ degrees of freedom.
A confidence interval was used to estimate the proportion of statistics students that are female.
wps.prenhall.com /bp_berenson_bbs_9/0,,576057-,00.utf8.html   (515 words)

  
 Lecture 10: Point and Interval Estimation
is the estimator whereas the estimate is 10.
When we choose an estimator to be used to make a point estimate of a particular population parameter, all we can do is compare the sampling distributions of the various estimators.
a statistic is a consistent estimator of a parameter if the probability that the statistic's value is very near the parameter's value increasingly approaches 1 as the sample size increases.
www.unc.edu /~knhighto/econ70/lec10/lec10.htm   (659 words)

  
 BioMed Central | Full text | Interval estimation and optimal design for the within-subject coefficient of variation for ...
The maximum like estimation and sample size estimation based on pre-specified width of confidence interval are novel contribution to the literature for the binary variable.
We note that the 95% confidence interval is somewhat relatively wide, and this may be due to the fact that the sample size is not large enough.
In this paper we have dealt with the issue of sample size estimation of the WSCV from continuous and binary scale measurements focusing on random measurement error, in the conventional way that reliability is usually discussed.
www.biomedcentral.com /1471-2288/6/24   (4519 words)

  
 CSI Math
The most widely seen use of confidence intervals is the estimation of population proportion through surveys or polls.
The fact that not all confidence intervals contain the true value of the parameter is often illustrated by plotting a number of random confidence intervals at once and observing.
For this data, the confidence interval is enormous as the size of the sample is small and the range is huge.
www.math.csi.cuny.edu /Statistics/R/simpleR/stat010.html   (1942 words)

  
 Interval Estimation
Valid interval estimation typically requires a method of estimating the variance of the point estimator
This relation involves three parameters, estimator for mean, estimator for variance, and the degree of freedom.
Estimator for the variance and for the degree of freedom has to consider two separate cases
www.eg.bucknell.edu /~xmeng/Course/CS6337/Note/master/node80.html   (228 words)

  
 OECD Glossary of Statistical Terms - Estimation
Estimation is concerned with inference about the numerical value of unknown population values from incomplete data such as a sample.
If an interval is calculated within which the parameter is likely, in some sense, to lie, the process is called interval estimation.
Estimation is the means by which this inflation occurs.
stats.oecd.org /glossary/detail.asp?ID=860   (144 words)

  
 Interval Estimation
Set estimation refers to the process of constructing a subset of the parameter space, based on observed data from a probability distribution.
In this chapter, we explore the basic method of set estimation using pivot variables.
We study set estimation in some of the most important models: the single variable normal model, the two-variable normal model, and the Bernoulli model.
www.math.uah.edu /stat/interval   (93 words)

  
 Interval estimation - Search Results - MSN Encarta
Interval estimation - Search Results - MSN Encarta
In Western music, the names of intervals reflect the number of tones of the diatonic scale (the...
Search for books about your topic, "Interval estimation"
encarta.msn.com /encnet/refpages/search.aspx?q=Interval+estimation   (138 words)

  
 Power Analysis
An increasing number of influential statisticians are suggesting that confidence interval estimation should augment or replace traditional hypothesis testing approaches in the analysis of experimental data.
The figure shows confidence intervals for the difference between means for 3 experiments, all performed in the same domain, using measures with approximately the same variability.
In spite of the obvious advantages of interval estimates, they are seldom employed in published articles in many areas of science.
www.statsoft.com /textbook/stpowan.html   (5356 words)

  
 Module 5.2: Confidence Interval Estimation and Hypothesis Testing for a Proportion   (Site not responding. Last check: 2007-10-13)
One of the most popular applications of confidence intervals for the population proportion is the manner in which public opinion polls are reported.
A confidence interval for the true population parameter being estimated is the sample estimate of that parameter plus/minus the sampling error.
Note that the confidence interval confirms the result of the test of hypothesis, which will always be the case with a not equal, two-tailed alternative hypothesis.
ruby.fgcu.edu /courses/tharring/80890/m5_2.htm   (1733 words)

  
 A robust approach to reference interval estimation and evaluation -- Horn et al. 44 (3): 622 -- Clinical Chemistry
estimate of reference intervals with a small number of samples.
estimator for skewed populations as its upper endpoint (9).
interval for each of the point estimators (10).
www.clinchem.org /cgi/content/full/44/3/622   (3358 words)

  
 Confidence Interval Estimation   (Site not responding. Last check: 2007-10-13)
A 95% confidence interval for the hourly income of the UB work-study students has an upper limit of 6.902777778 + 0.231678109 and a lower limit of 6.902777778 - 0.231678109.
is the interval coefficient providing an area of a/2 in the upper tail of a t distribution with n-1 degrees of freedom which can be found from a t distribution table (for example the interval coefficient for a 90% confidence level is 1.833 if the sample is 10).
Now, like the calculation of the confidence interval for the large sample, calculate the confidence interval of the population based on this small sample information.
www.cs.engr.uky.edu /~rdbai/links/stat_confide.html   (810 words)

  
 Interval Estimation of a Normal Process Mean from Rounded Data
Elementary methods of point estimation of distribution parameters and the construction of confidence intervals are based on an implicit assumption that observed data are essentially "exact." It is of interest to know what happens to the statistical properties of these methods when, in fact, the available data are produced by relatively crude gaging.
Our main purpose in this paper is to investigate the properties of interval estimators of the parameter µ based on rounded normal data.
One is the traditional t interval (appropriate for exact normal data), and the other is obtained from inversion of (rounded data) likelihood ratio tests for µ.
www.asq.org /pub/jqt/past/vol33_issue3/qtec_33_3_335.htm   (353 words)

  
 Chapter 7 Statistical Inference: Interval Estimation and Hypothesis Testing
Confidence intervals and sample size are basic principles that are drummed in all undergraduate stat's courses, so we are not going to spend time on them.
Basically it demonstrates the confidence interval, or error values must determine for a mean generated from sample data in order to be certain that the true mean is contained within the confidence interval.
Note the assumptions concerning either the distribution of the Population to be sampled or the size of the sample.
www.ac.wwu.edu /~patrick/geo510/studC7.htm   (1118 words)

  
 Interval estimation
Answer 7.2 We don't always want to use a very high confidence, because the interval would be very long.
We have to trade off the length of the interval against the confidence percentage.
is very small then it becomes more difficult to obtain intervals with approximately a 95% confidence.
stats.lse.ac.uk /knott/tiger.links/stats2/selftest/node7.html   (163 words)

  
 STATISTICA Power Analysis
Modern statistical practice has placed renewed emphasis on confidence interval estimation, both in planning studies and evaluating their meaning.
STATISTICA Power Analysis is unique among programs of its type in that it calculates confidence intervals for a number of important statistical quantities such as standardized effect size (in t-tests and ANOVA), the correlation coefficient, the squared multiple correlation, the sample proportion, and the difference between proportions (either independent or dependent samples).
These capabilities, in turn, may be used to construct confidence intervals on quantities such as power and sample size, allowing the user to utilize the data from one study to construct an exact confidence interval on the sample size required for another study.
www.statsoft.com /products/power_an.html   (1154 words)

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