what is a sampling error 
a sampling error is a statistical error that occurs when an analyst does not select a sample that represents the entire population of data as a result the results found in the sample do not represent the results that would be obtained from the entire population sampling is an analysis performed by selecting a number of observations from a larger population the method of selection can produce both sampling errors and non sampling errors understanding sampling errorsa sampling error is a deviation in the sampled value versus the true population value sampling errors occur because the sample is not representative of the population or is biased in some way even randomized samples will have some degree of sampling error because a sample is only an approximation of the population from which it is drawn calculating sampling errorthe sampling error formula is used to calculate the overall sampling error in statistical analysis the sampling error is calculated by dividing the standard deviation of the population by the square root of the size of the sample and then multiplying the resultant with the z score value which is based on the confidence interval sampling error z n where z z score value based on the confidence interval approx 1 96 population standard deviation n size of the sample begin aligned text sampling error z times frac sigma sqrt n textbf where z z text score value based on the qquad text confidence interval approx 1 96 sigma text population standard deviation n text size of the sample end aligned sampling error z n where z z score value based on the confidence interval approx 1 96 population standard deviationn size of the sample types of sampling errorsthere are different categories of sampling errors a population specific error occurs when a researcher doesn t understand who to survey selection error occurs when the survey is self selected or when only those participants who are interested in the survey respond to the questions researchers can attempt to overcome selection error by finding ways to encourage participation a sample frame error occurs when a sample is selected from the wrong population data a non response error occurs when a useful response is not obtained from the surveys because researchers were unable to contact potential respondents or potential respondents refused to respond eliminating sampling errorsthe prevalence of sampling errors can be reduced by increasing the sample size as the sample size increases the sample gets closer to the actual population which decreases the potential for deviations from the actual population consider that the average of a sample of 10 varies more than the average of a sample of 100 steps can also be taken to ensure that the sample adequately represents the entire population researchers might attempt to reduce sampling errors by replicating their study this could be accomplished by taking the same measurements repeatedly using more than one subject or multiple groups or by undertaking multiple studies random sampling is an additional way to minimize the occurrence of sampling errors random sampling establishes a systematic approach to selecting a sample for example rather than choosing participants to be interviewed haphazardly a researcher might choose those whose names appear first 10th 20th 30th 40th and so on on the list one way to reduce the likelihood of sampling error is to use a larger sample size the monthly employment situation report compiled each month by the bureau of labor statistics is calculated from a survey of 119 000 businesses and government agencies due to the enormous sample size these surveys have an extremely low rate of sampling error 1examples of sampling errorsassume that xyz company provides a subscription based service that allows consumers to pay a monthly fee to stream videos and other types of programming via an internet connection the firm wants to survey homeowners who watch at least 10 hours of programming via the internet per week and that pay for an existing video streaming service xyz wants to determine what percentage of the population is interested in a lower priced subscription service if xyz does not think carefully about the sampling process several types of sampling errors may occur a population specification error would occur if xyz company does not understand the specific types of consumers who should be included in the sample for example if xyz creates a population of people between the ages of 15 and 25 years old many of those consumers do not make the purchasing decision about a video streaming service because they may not work full time on the other hand if xyz put together a sample of working adults who make purchase decisions the consumers in this group may not watch 10 hours of video programming each week selection error also causes distortions in the results of a sample a common example is a survey that only relies on a small portion of people who immediately respond if xyz makes an effort to follow up with consumers who don t initially respond the results of the survey may change furthermore if xyz excludes consumers who don t respond right away the sample results may not reflect the preferences of the entire population sampling error vs non sampling errorthere are different types of errors that can occur when gathering statistical data sampling errors are the seemingly random differences between the characteristics of a sample population and those of the general population sampling errors arise because sample sizes are inevitably limited it is impossible to sample an entire population in a survey or a census a sampling error can result even when no mistakes of any kind are made sampling errors occur because no sample will ever perfectly match the data in the universe from which the sample is taken company xyz will also want to avoid non sampling errors non sampling errors are errors that result during data collection and cause the data to differ from the true values non sampling errors are caused by human error such as a mistake made in the survey process if one group of consumers only watches five hours of video programming a week and is included in the survey that decision is a non sampling error asking questions that are biased is another type of error 