Dear Md. Ashraf Uzzaman ,

Go to http://www.raosoft.com/samplesize.html and you get immediately the sample you need.

Bests,

Igor Gurkov

Statistically (ISO 2859?)!  There was a discussion on Linkedin.

Depends on how close you wish to be to the 'truth'...

Hi, 

You have many websites that propose to calculte sample size:

• http://www.raosoft.com/samplesize.html
• http://clincalc.com/stats/samplesize.aspx
• https://www.surveysystem.com/sscalc.htm

And here it is a paper answering to your second question: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2876926/

I hope that will help you,

Julian

The sample size must be 5 to 10 % of the popullation and in the case of  a small population (less 100) all the population. 

Which sample size is needed depend on the analyses  you make, and which statistics you focus on. Different statistics from the same research implementatin may require different sample sizes.

If you ar using the Mplus program for you analyses (which are recommended, as this is a very, very flexible and easy program with a lot of support material), you can determine sample size using Monte Carlo techniques.

See: Muthén, L.K. & Muthén, B.O. (2002). How to use a Monte Carlo study to decide on sample size and determine power. Structural Equation Modeling, 4, 599-620.

The following sources are also helpful: 

• Burmeister, E. and Aitken, L. M. (2012). Sample size: How many is enough? Australian Critical Care, 25, 4, pp. 271-274.
• Lenth, R. V. (2001). Some Practical Guidelines for Effective Sample Size Determination. The American Statistician, 55, 3, pp. 187-193. 
• Sample Size Calculation? : https://www.researchgate.net/post/Sample_Size_Calculation 

Dear RG colleague,

Determining the sample sizes involve resource and statistical issues. Usually, researchers regard 100 participants as the minimum sample size when the population is large. However, In most studies the sample size is determined effectively by two factors: (1) the nature of data analysis proposed and (2) estimated response rate.

For example, if you plan to use a linear regression a sample size of 50+ 8K is required, where K is the number of predictors. Some researchers believes it is desirable to have at least 10 respondents for each item being tested in a factor analysis, Further, up to 300 responses is not unusual for Likert scale development according to other researchers.

Another method of calculating the required sample size is using the Power and Sample size program (www.power-analysis.com).

Regards,

Dear RG colleague,

Determining the sample sizes involve resource and statistical issues. Usually, researchers regard 100 participants as the minimum sample size when the population is large. However, In most studies the sample size is determined effectively by two factors: (1) the nature of data analysis proposed and (2) estimated response rate.

For example, if you plan to use a linear regression a sample size of 50+ 8K is required, where K is the number of predictors. Some researchers believes it is desirable to have at least 10 respondents for each item being tested in a factor analysis, Further, up to 300 responses is not unusual for Likert scale development according to other researchers.

Another method of calculating the required sample size is using the Power and Sample size program (www.power-analysis.com).

Regards,

This formula is the easiest way to do it.

Dear Md. Ashraf Uzzaman ,

Go to http://www.raosoft.com/samplesize.html and you get immediately the sample you need.

Bests,

Igor Gurkov

Awesome information. Another helpful calculation table can be found at https://www.surveysystem.com/sscalc.htm

The problem with calculations as the above mentioned is that required sample sizes are different for different types of analyses, and for different types of effects.

In serious research you need to specify the analysis and make the required sample size calculations accordingly.

Hello everyone. I would have a question if you can please help. What would be the most representative sample or the best method to calculate this sample if I want to analyze the impact of Social Media in Tourism among Generation Y who are let's say approximately 3.5 million people? Thanks!

Alma Braimllari Spaho could you please explain why 5 to 10 % is a good sample? I don't seem to be able to find any literature on this regard. Thank you!

Bruce Neagle do you have the link to that discussion by chance? Thank you!

Unfortunately no.

Hi i m following mixed methodology , i will do survey and semi structure interview, whats the sample size should be ?

I am doing a quantitative study. The total population is 2320. What should be the adequate sample size?

with 95% confidence level and 5% error, it should be around 330

Simply, the sample size is related to the accuracy of the result you require. If you require 1% accuracy on the 'true' mean value then you'll need 10000 (random) participants, particles, experiments etc. The standard error is inversely proportional to the square of the number (of whatevers). Or the number of experiments, participants etc is inversely proportion to the variance (or the standard error squared).

Amee Joan For 0.01 (1%) standard error on the mean you'll need to sample them all. For 0.05 (5%) then 1/202 or 400 is a good guideline and in line with Akarsu Bayram above.

Alan F Rawle Thank you

Akarsu Bayram Thank you