What is the sample size, this question arises at the time when a researcher until at chapter research metodology. Chapter research methods loaded a couple of important points such as design, variable, population, sample, etc. Therefore, a study should understand each piece in order to research acceptable. This article will explain what is the sample size.
the sample size is the number of individuals, subject or elements drawn from population research, the measure would serve as a sample. Therefore, the sample size should be completely taken care of by a researcher. If the sample is too large or too small, then there is a chance his research would problematic.
a good sample is a representative sample that is able to reflect the population. Furthermore, in order for us to promptly step determines the size of the sample, let us refer to some of the following points:
First, Roscoe (1975) gave views on the appropriate sample size.
1 in General, the research may use the samples as many as over 30 to 500
2 If the study has multiple categories (for example: man-woman), then we recommend using at least 30 samples per category
3 when multivariate research (e.g. multiple regression or correlation;). then, the number of samples of at least 10 of the number of variables (e.g., 5 = 50 sample)
4 when a simple experiment research using experimental and control groups, number of samples could be between 10 to 20 for each.
Second, Malhotra (1993) gives the same thing with Roscoe (1975) (points no. 3) that, the sample size can be determined by means of multiplying by the number of variables. the number of variables multiplied 5, example; If the variable number of 10, then the sample used 50.
Third, the sample size according to slovin. a formula of slovin is given us the follow:
n = a sample size
N = population size
e = desired margin of eror
Fourth, Gay (1976) offers:
1 descriptive research (10% of the population) and for a smaller population (20%)
2 correlational research – 30 samples
3 ex post facto / causal comparatif (15 samples per group)
4 experimental research (15 samples per group)
Malhotra K. Naresh. 1993. Marketing Research An Applied Orientation, second edition, Prentice Hall International Inc, New Jersey
Consuelo G, et all. 1992. Research Mhetods, Revised edition, Quezon City