JP Carrascal jpcarrascal
jpcarrascal
/ survey_sample_size.R
Created
November 18, 2019 16:26
Estimate optimal sample size for a survey given the size of the population, the desired confidence level and margin of error.
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| # Simple function to determine optimum sample size for a survey. | |
| # A lot of websites provide online calculators, but here is the code so you can do it yourself in R. | |
| # Source: | |
| # Krejcie, Robert V., and Daryle W. Morgan. "Determining sample size for research activities." | |
| # Educational and psychological measurement 30.3 (1970): 607-610. | |
| # https://journals.sagepub.com/doi/abs/10.1177/001316447003000308?journalCode=epma | |
| # Downloadable PDF: https://home.kku.ac.th/sompong/guest_speaker/KrejcieandMorgan_article.pdf | |
| # | |
| # The paper provides a table with chi-squared distribution values for 1 degree of freedom. | |
| # R function qchisq() generates the right value from a given confidence level, so the table is not needed. |