A sampling error occurs when a sample drawn from a population deviates fro🍸m representing the true or entire population.
What Is a Sampling Error?
Sampling is an analysis performed by selecting several observations from a 🎃larger population. The method of selection can produce both sampling errors and non-sampli🍒ng errors. A sampling error is a deviation between the sampled value and the true population value.
Key Takeaways
- 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.
- The prevalence of sampling errors can be reduced by increasing the sample size.
- In general, sampling errors can be placed into four categories: population-specific error, selection error, sample frame error, or nonresponse error.
Understanding Sampling Errors
A sampling error is a deviation in the sampled value vs. 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 iꦍs onlyꩲ an approximation of the population from which it is drawn.
Calculating a Sampling Error
The 澳洲幸运5开奖号码历史查询:sampling error formula is used to calculate the overall sampling error in statistical analysis. The sampling error is calculated by dividing the 澳洲幸运5开奖号码历史查询: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×nσwhere:Z=Z score value ౠbased on the confidence interval (approx=1.96)σ=Population standard deviationn=Size of the sample
Types of Sampling Errors
Ther🐼e are different categories of sampling errors.
Population-specific error
A population-specific error occurs when a res♎earcher doesn’t understand who to survey.
Selection error
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 error𒈔s by finding ways to encourage participation.
Sample frame error
A sample frame error occurs when a sample is selected from the wrong population data.𒁏
Nonresponse error
A nonresponse error occurs when a useful response is not obtained from the🍸 surveys because researchers were unable𝔍 to contact potential respondents (or potential respondents refused to respond).
Eliminating Sampling Errors
The 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 popu💎lation.
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 s𒁏ubjꦬect or multiple groups, or undertaking multiple studies.
Random sampling is an additional way to minimﷺize 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, 40꧂th, and so on, on the list.
Fast Fact
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 U.S. 澳洲幸运5开奖号码历史查询: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.
How Do Sampling Errors Apply to Real Life?
Sampl🌼ing is often used by businesses and governments and in finance. It is relied on to make critical decisions and is particularly common in economic research.
Sampling helps companies predict customer behavior, estimate future demand, and set prices. It also helps financial institutions detect fraud by auditing transactions.
Sampling errors can affect the validity of their research findings and the ⭕quality of their data. They also won’t be as confident in their decision-making.
Examples of Sampling Errors
Assume that XYZ Company provides a subscriptio🐠n-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 who pay for an existing video streaming service. XYZ wants to dete𓃲rmine 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 occ꧒ur.
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 ages 15 to 25, 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 respon🐟d. 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 Error
Different types of errors can occur when gathering statistical data. Sampling errors are the seemingly random differences between the characteristics of a sa♋mple 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.)
Important
A sampling error can result even when no mistakes of any kind are made; samp🔯ling errors occur because no sample will ever perfectly match the data in the universe from which the sample is taken.
XYZ Company will also want to avoid non-sampling errors. These are errors that result during data co🎀lle🌠ction 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 biased questions is another type of error.
What Is Sampling Error vs. Sampling Bias?
In statistics, sampling means select♔ing the group that you will collect data from in your research🦹.
Sampl💟ing errors are statistical errors that arise when a sample does not represent the whole population once analyses have been undertaken.
Sampling bias is🅠 the expectation, which is known in advance, that a sample won’t be representative of the true population—for instance, if the sample ends up having proportionally more women or young people♈ than the overall population.
Why Is Sampling Error Important?
Being aware of the presence of sampling e𒅌rrors is important because it can be an indicator of the level of confidence that can be placed in t𒅌he results. Sampling error is also important in the context of a discussion about how much research results can vary.
How Do You Find the Sampling Error?
In survey rese♏arch, sampling errors occur because all samples are representative samples: a smaller group that stands in for the whole of your research population. It’s impossible to survey the entire group of people you’d l♐ike to reach.
It’s not usually possible to quantify the degree of samp🐼ling error in a study, since it’s impossible to collect the relevant data from the entire population you are studying. This is why rese༒archers collect representative samples (and representative samples are the reason why there are sampling errors).
What Is Sampling Error vs. Standard Error?
Sampling error is derived from the 澳洲幸运5开奖号码历史查询:standard error (SE) by multiplying it by a Z-score value to produce a 澳洲幸运5开奖号码历史查询:confidence interval.
Thꦿe standard error is computed by divi🌱ding the standard deviation by the square root of the sample size.
The Bottom Line
Sampling error occurs when a𝕴 sample drawn from a population deviates somewhat from that true population. Large sampling err๊ors can lead to incorrect estimates or inferences made about the population based on statistical analysis of that sample.
In general, sampling errors can be placed into four categories: population-specific error, selection error, sample frame error, or nonresponse error. A population-specific error occurs when the researcher does not understand who they should survey. A selection error occurs when respondents self-select their participation in the study. (This results in only those who are interested in responding, which 🐈skews the results.) A sample frame error occurs when the wrong subpopulation is used to select a sample. Finally, a nonresponse error occurs when potential respondents are not successfully contacted or refuse to respond.