Total population sampling technique pdf

Freedman department of statistics university of california berkeley, ca 94720 the basic idea in sampling is extrapolation from the part to the wholefrom the sample to the population. Foot measurement study of the population of taiwan. The number of samples selected from each stratum is proportional to the size, variation, as well as the cost c i of sampling in each stratum. The words that are used as synonyms to one another are mentioned. Total population sampling is a type of purposive sampling where the whole population of interest i. Some common sample designs described in the literature include purposive sampling, random sampling, and quota sampling cochran 1963, rao 1985, sudman 1976. Failed in 1936 the literary digest poll in 1936 used a sample of 10 million, drawn from government lists of automobile and telephone. Slovins formula allows a researcher to sample the population with a desired degree of accuracy. Likewise, the module on tabulation module 4 contains instructions for producing standard labour market statistics, such as the unemployment rate, that researchers can use for any number. In the regards, this paper also presents the different types of sampling techniques and methods. Sampling problems may differ in different parts of the population. Simple random sampling in this technique, each member of the population has an equal chance of being selected as subject. We may select all ssus for convenience or few by using a specific element sampling techniques such as simple random sampling. Random sampling without replacement such that every possible sample of n units has the same probability of selection.

I the population is cows of the same breed on dairy farms. History of sampling contd dates back to 1920 and started by literary digest, a news magazine published in the u. It is also the most popular way of a selecting a sample because it creates samples that are very highly representative of the population simple random is a fully random technique of selecting subjects. 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. In sampling, a section of the population that is selected represents the entire population. Assign a number from 1 to 1,125 to each record and randomly select 120 numbers from 1 to 1,125 without. Sampling is one of the most important aspects of research design. I the population is all plantations in costa rica where. Outcome of sampling might be biased and makes difficult for all the elements of population to be part of the sample equally. The manual for sampling techniques used in social sciences is an. A study on purposive sampling method in research neetij rai bikash thapa chapter i.

Study of possible trends in the health status of the population. This technique is more reliant on the researchers ability to select elements for a sample. Quota sampling is a non random sampling technique in which participants are chosen on the basis of predetermined characteristics so that the total sample will have the same distribution of characteristics as the wider population davis, 2005. Could be extremely large if population is national or international in nature. Nonprobability sampling techniques depend on the subjective judgment of the researcher or evaluator to select units from the population for inclusion in the sample. May 10, 2018 total population sampling is a type of purposive sampling where the whole population of interest i. Sampling total population sampling is a type of purposive. Furthermore, as there are different types of sampling techniques methods, researcher needs to understand the differences to select the proper sampling method for the research. The nonprobability sampling procedure might have limited the generalisability of the findings. Population sampling representative subset of a population. Suppose we sample randomly from a real population, for example all births in a given country.

Then, samples are selected within each stratum, either through simple or systematic sampling. Nonprobability population sampling method is useful for pilot studies, case studies, qualitative research, and for hypothesis development. Each of the sampling techniques described in this chapter has advantages and disadvantages. This relationship has been most clearly described in quantitative studies, where the sampling method has a direct bearing on the reliability, validity, replicability, and generalizability of the study. Stratified type of sampling divide the universe into several sub group of population that are individually more homogeneous than the total population the subpopulations differences are called strata and. Multistage sampling this sample is more comprehensive and representative of the population. This is the purest and the clearest probability sampling design and strategy. We say items because the subset of things to include in your study may not always be people. A sampling frame is a list of the actual cases from which sample will be drawn.

Simple random sampling, systematic sampling, stratified sampling fall into the category of simple sampling techniques. To study the consumption pattern of households, the people living in houses, hotels, hospitals, prison etc. According to showkat and parveen 2017, the snowball sampling method is a nonprobability sampling technique, which is also known as referral sampling, and as stated by alvi 2016, it is. Every descriptive measure value shown there is a parameter, as it is computed from information obtained from the entire population. Raj, p4 all these four steps are interwoven and cannot be considered isolated from one another. Pros of simple random sampling one of the best things about simple random sampling is. Sample for each category selected randomly from the population age group population 000s sample male female total male female total 04 830 772 1602 41 38 79 59 1005 945 1950 50 47 97 1014 1016 958 1974 51 48 99 1519 929 885 1814. The method of selecting samples from a population is known as sampling. It is most practical when the total population is of manageable size, such as a welldefined subgroup of a larger population. The entire process of sampling is done in a single step with each subject selected independently of the other members of the population. A sample is a portion of the population selected for analysis.

The population parameters are presented in table 91, along with the simple data array from which they were derived. Slovins formula gives the researcher an idea of how large the sample size needs to be. Sampling survey census it is also known as population survey and complete enumeration survey. A subgroup of the whole population is selected for data collection e. Sampling frame a list of all the elements in the population from which the sample is drawn. Sampling techniques we can say that there are three types of sampling. Digest successfully predicted the presidential elections in 1920, 1924,1928, 1932 but. Divide the population into strata mutually exclusive classes, such as men and women. The primary goal of sampling is to get a representative sample, or a small collection of units or cases from a much larger collection or population, such that the researcher can study the smaller group and produce accurate generalizations about the larger group. Sample units tcyr vbtcyr btsrs vbbtsrs 1 1,2 265 8 260 72 2 1,3 263.

Whilst total population sampling is infrequently used, there are specific types of. Distinguishing between a sample and a populat ion before describing sampling procedures, we need to define a few key terms. The term population means all members that meet a set of specifications or a specified criterion. Sampling methods chapter 4 it is more likely a sample will resemble the population when. The random sampling can also be of different types. Unlike the population mean or proportion, estimating the population total requires that we know the number of sampling units in a population, n. I the sample is the three sites where data was collected.

Appendix iii is presenting a brief summary of various types of nonprobability sampling technique. Estimating population mean and total under simple random sampling. In a research context, sampling refers to the process of selecting a subset of items from a defined population for inclusion into a study. Subsequently, a random sample is taken from these clusters, all. This paper presents the steps to go through to conduct sampling. Cluster sampling is where the whole population is divided into clusters or groups. A sampling and recruitment method in which existing study subjects or a small group of known contacts helps to recruit future subjects from among their acquaintances. We may select the psus by using a specific element sampling techniques, such as simple random sampling, systematic sampling or by pps sampling. The proper choice of the sampling units depends on a number of factors.

Thus, the mean number of intrave nous drug injections in th e population shown in figure 33 is. Estimating the population total like the population mean, the total number of entities in the population is another attribute estimated commonly. The individuals are selected from different stages for constituting the multistage sampling. The population is sometimes rather mysteriously called the universe. A manual for selecting sampling techniques in research 5 of various types of probability sampling technique. Sampling the process of selecting a group of people, events, behaviors, or other elements with which to conduct a study. Sampling techniques basic concepts of sampling essentially, sampling consists of obtaining information from only a part of a large group or population so as to infer about the whole population. Sampling process 6 target population the enumeration of objects that possess the necessary information, which needs to be collected e.

When random sampling is used, each element in the population has an equal chance of being selected simple random sampling or a known probability of being selected stratified random sampling. Purposive sampling in this technique, sampling units are selected according to the purpose. Sampling is a technique procedure or device employed by a researcher to systematically select a relatively smaller number of representative items or individuals a subset from a predefined population to serve as subjects data source for observation or experimentation. The selection of a sample has a profound effect on the ultimate quality of the research. Example if we are interested in studying population of 40 percent of females and 60 percent of males. This type of sampling is also known as nonrandom sampling.

In the case of longitudinal data there is a special problem. This sample would not be reflective of the whole hospital population. Stages of a population are usually available within a group or population, whenever stratification is done by the researcher. Total population sampling is a type of purposive sampling technique that involves examining the entire population i. A manual for selecting sampling techniques in research. Some researchers prefer this sampling technique because it is cheap, quick and easy. A manual for selecting sampling techniques in research munich. This sampling method is usually employed in studies that are not interested in the parameters of the entire population. Sampling in qualitative research sage research methods. The sample is referred to as representative because the characteristics of a properly drawn sample represent the parent population in all ways. For total intravenous drug injections, th e mean in the population is derived using formula 3. Sampling and its relevance for sound data collection. Harvey goldstein, peter lynn, graciela munizterrera, colm o.

Sampling technique there are two ways in which the information is collected during statistical survey. Comparison of convenience sampling and purposive sampling. Samples and populations samples and populations 7 21 samples and populations cont. Advantages a it is a good representative of the population.