2006-08-13 21:45:21 · 4 answers · asked by Garden Isle Girl 2 in Social Science ➔ Economics
Random selection methods help us in selecting representative and unbiased sample from a large population of units which we want to study. The units could be all persons in a community, all households in a city,all doctors in a country etc.depending on the objectives of our study. As the population is large, we ususally will have neither money, time nor personnel to collect the data we need from all the units in the population. Sample selected from such a large population using random selection method gives us estimates about the the population ( for example, the average annual income of the persons contained in the population we are studying) by using the data collected from the units in the sample. For selection of sample from a population by using random selection method, we have to first prepare a list of all units in the population which is called the sample frame. The random selection method selects a sample from this list--the sample frame--using procedures ensuring that every unit in the population has a chance of being included in the sample. This is called a random sample which gives unbiased information about the population along with an indicator of the margin of error involved in estimating the characteristics of a large population from a sample which is usually quite small in size. The preparation of the sample frame is an essential step in using random selection methods for getting a random sample from a large population.
2006-08-14 02:30:33 · answer #1 · answered by Anonymous · 0⤊ 0⤋
A sampling frame is simply the population from where you can extract your random sample.
For example, if you are interested on the effects women feel when pregnant, then your sampling frame would only consist of women who have been pregnant. On the other hand, if you were interested in why men choose to shave or not, then your sampling frame should include only men of over a certain age, probably 16 or 18.
The sampling frame provides the reference point for you to conduct your sampling and your research.
2006-08-14 01:44:51 · answer #2 · answered by ekonomix 5 · 0⤊ 0⤋
The sample frame is required to get a representative sample resembling the surveyed category.If the sample is not perfect result will not be reliable.Randaom sampling by its name itself makes results not sure because "random"selection.If there no sample frame also is not there result will be unreliable
2006-08-15 17:26:21 · answer #3 · answered by leowin1948 7 · 0⤊ 0⤋
Because u need some data for calculation
2006-08-14 00:23:41 · answer #4 · answered by Anonymous · 0⤊ 0⤋