Title: Confidence interval - Simple English Wikipedia, the free encyclopedia
Headings: Confidence interval
Confidence interval
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Meaning of the term "confidence"
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Content: Confidence interval - Simple English Wikipedia, the free encyclopedia
Confidence interval
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In statistics, a confidence interval, abbreviated as CI, is a special interval for estimating a certain parameter, such as the population mean. With this method, a whole interval of acceptable values for the parameter is given instead of a single value—together with a likelihood that the real (unknown) value of the parameter will be in the interval. Thus, if we're not sure of the exact number of vehicles that crossed a bridge, we can say 400 plus or minus 10 instead of just saying 400. The confidence interval is based on the observations from a sample, and hence differs from sample to sample. The likelihood that the parameter will be in the interval is called the confidence level, and the end points of the confidence interval are referred to as confidence limits. Very often, this is given as a percentage (for example, the 95% confidence interval). The confidence interval is always given together with the confidence level.