Calculating sample size for stratified random sample. For the love of physics walter lewin may 16, 2011 duration. Slovin 1960 presents a formula to determine the size of a sample as follows. Slovins formula is used to calculate the sample size n given the population size n and a margin of error e. Aug 30, 20 for the love of physics walter lewin may 16, 2011 duration. This formula uses to determining the number of sample from this population. It is also usually necessary to make an allowance for dropouts. Sampling theory chapter 4 stratified sampling shalabh, iit kanpur page 5 now 1 1 1 1 k stii i k i i i ey ney n ny n y thus yst is an unbiased estimator of y. November 20, analysis of sample size in consumer surveys, gfk polonia 18 sample size analysis of impact on quality measures sample size correlation bcs with ref. If the population to be sampled has obvious subgroups, slovins formula could be applied to each individual group instead of the whole group. The famous book on sampling techniques by cochran has three editions. Mar 15, 2011 slovin s formula sampling techniques by steph ellen, ehow contributor when it is not possible to study an entire population such as the population of the united states, a smaller sample is taken using a random sampling technique. Raj, p10 such samples are usually selected with the help of random numbers. The research locals this portion of the presentation contains a description of the place where the respondents are to be obtained.
We will illustrate with the above formula to determine the sample size from a given population. Advantages a it is a good representative of the population. Sampling is a research method where subgroups are selected from a larger group known as. Gonzales sampling sampling process of selecting members or elements of a sample from a given population. Slovins formula minimum acceptable sizes descriptive research 10 percent of the population. Slovins formula sampling techniques by stephanie ellen. To estimate the design effect, an estimate of either. Sample size for 3%, 5%, 7% and 10% precision levels where confidence level is 95% and p. In some of the stepsthe definition of the population, the determination of the data to be collected and of the methods of measurement, and the. If each stratum is homogeneous, in that the measurements vary little from one unit to another, a precise estimate of any stratum mean can be obtained from a small sample in that. Dalam metode probability sampling, seluruh unsur misalnya. In probability sampling, each unit is drawn with known probability, yamane, p3 or has a nonzero chance of being selected in the sample.
Here is the slovin formula for measuring the sample in this research. For example a population of schools of canada means all the schools built under the boundary of the country. Use slovins formula to find out what sample of a population of 1,000 people you need to take for a survey on their soda preferences. Many investigations are conducted by survey research. Nevertheless, the general features of the above hold. Statquest sample size and effective sample size, clearly explained duration. Slovin s formula is used in statistical analysis as a tool to determine the sample size of a population that must be taken for a specific study. For smaller populations, a minimum of 20 percent may be required. Disadvantages a it is a difficult and complex method of samplings. This formula is only used when the sample size is unknown. Slovin s formula allows a researcher to sample the population with a desired degree of accuracy. Slovin formula sampling techniques margin of error sampling. Population is an accessible group of people who meets a welldefined set of eligibility criteria. Hal ini dikarenakan penelitian dengan menggunakan jumlah populasi secara keseluruhan akan memakan waktu yang lama dan biaya yang sangat besar.
This calculation is based on the normal distribution, and assumes you have more than about 30 samples. Use simple random sampling equations for data from each stratum. This formula was used to calculate the sample sizes in tables 2 and 3 and is shown below. The three will be selected by simple random sampling. She coauthored a statistics textbook published by houghtonmifflin. Desired analysis may not be possible or effective key to good sampling. A probability sampling scheme is one in which every unit in the population has a chance greater than zero of being selected in the. Individual respondents within households taking clustering into account can be done in several ways ad hoc, using the socalled design factor. This list of the steps in a sample survey has been given in order to emphasize that sampling is a practical business, which calls for several different types of skill. Using slovin formula what will be the appropriate way for determining sample size using farmer list in a study involving three communities. If the population to be sampled has obvious subgroups, slovins formula could be. Who is slovin and where and how did the slovins formula. Who is slovin and where and how did the slovins formula for. The sample of this research consisted of 55 teachers taken using simple random sampling technique based on slovins formula from 123 high.
The proper choice of the sampling units depends on a number of factors. Tps 2012 final for printing dd philippine statistical. Slovins formula is used to determine the sample size. Menentukan ukuran sampel dengan formula cochran, w. First of all you should be working with a finite population and if the population size is known, the yamane formula for determining the sample size is given by. The slovin s formula is quite popularly use in my country for determining the sample size for a survey research, especially in undergraduate thesis in education and social sciences, may be because. Specific sampling techniques are used for specific research problems because one technique may not be appropriate for all problems. Slovin s formula calculates the number of samples required when the population is too large to directly sample every member. If you take a population sample, you must use a formula to figure out what sample size you need to take. Slovins formula is used in statistical analysis as a tool to determine the sample size of a population that must be taken for a specific study. If youd like to see how we perform the calculation, view the page source.
Using slovin formula what will be the appropriate way for. Slovins formula sampling techniques by steph ellen, ehow contributor when it is not possible to study an entire population such as the population of the united states, a smaller sample is taken using a random sampling technique. To study the consumption pattern of households, the people living in houses, hotels, hospitals, prison etc. It includes a brief description of the location whether urban or rural.
The slovins formula is quite popularly use in my country for determining the sample. Sampling bias nonrandom differences, generally the fault of the researcher, which. Slovins formula calculates the number of samples required when the population is too large to directly sample every member. When sampling large populations, use slovins formula to determine the necessary sample size. A manual for selecting sampling techniques in research.
Probability sampling a term due to deming, deming is a sampling porcess that utilizes some form of random selection. This is suggested by the name strata, with its implication of a division into layers. Requires time effort money careful planning slovins formula there are scientific ways of determining a representative acceptable sample size from any. Every member of the population is equally likely to be selected.
Apr 07, 2011 statquest sample size and effective sample size, clearly explained duration. Cochran membagi 2 teknik menentukan sampel berdasarkan data populasi yang bersifat kontinu dan bersifat kategori. International journal of education and research vol. In order to obtain reliable of data, researcher has increased sample size to 400 persons. Slovins formula allows a researcher to sample the population with a desired degree of accuracy. Requires time effort money careful planning slovins formula there are scientific ways of determining a representative acceptable sample size from any given population. Probability proportional to size pps takes varying sample sizes into account. The sample of this study is 183 students, by using slovin formula.
Slovins formula calculates the required sample size for simple. Stephanie ellen teaches mathematics and statistics at the university and college level. Sampling is a research method where subgroups are selected from a larger group known as a target population. Slovin formula sampling techniques free download as word doc. Thats when you can use slovins formula to figure out what sample size you. In the absence of data on the subject, a decision taken is just like leaping into the dark. A manual for selecting sampling techniques in research 10 population and a sample population target population refers to all the members who meet the particular criterion specified for a research investigation. If the population to be sampled has obvious subgroups, slovin s formula could be applied to each individual group instead of the whole group. Yakni probability sampling dan nonprobability sampling. Population divided into different groups from which we sample randomly.
Cara menentukan jumlah sampel dengan rumus slovin dalam melakukan penelitian pada suatu populasi, kita sering menggunakan sampel untuk mewakili populasi tersebut. N should always be given, that s what you should first settle before finding the sample. Dalam metode ini, cara pemilihan sampel harus dilakukan secara acak random. Take for example a project a student have a total population of about 400 respondents and wishes to determine the sample size. The technique of sampling and determination of sample size have crucial role in surveybased research problems in applied statistics.
Where n is the sample size, n is the population size, and e is the level of precision. If it is a notable formula and it can be backed up by reliable sources, perhaps an article should be written about it. Sampling techniques introduction many professions business, government, engineering, science, social research, agriculture, etc. For example, you might want a confidence level of 95 percent giving you an alpha level of 0. Sampling problems may differ in different parts of the population. When it is not possible to study an entire population such as the population of the united states, a smaller sample is taken using a random sampling technique. Sampling sample size determination sampling statistics.
The selection of sampling methods and determination of sample. If the sample is correctly chosen the results can be used to represent the target population. Simple random sampling in an ordered systematic way, e. Secara umum, terdapat dua pendekatan dalam metode pemilihan sampel.
315 703 229 451 295 1460 1045 160 359 721 471 661 1642 1660 728 708 216 486 270 1068 886 1036 23 1003 89 1032 1092 1264 528 595 1137 66 962 1297 671 116 1450