As survey is a very useful approach for conducting descriptive research ( Quantitative) one is expected to make predictions by using statistical methods and therefore using an appropriate sample size based on calculations of N (Population size) assumes importance. Even when using non-probability approach using large sample size enables an individual to use multivariate and other techniques for drawing conclusions about unknown population parameters.
Hi Romans, Determination of sample size for survey is very important. It depends on the number of questions and items measured in the survey. In addition, sample size depends on your hypothesis and the type of statistical analyses that you want to undertake. For example, if you want to run multivariate statistical analysis such as regression modelling or structural equation modelling then your sample size needs to be bigger e.g. n=300 & minimum 150-200 cases/participants in your final analysis. Refer to section 3.9 on Sample Size in my PhD thesis available at https://bura.brunel.ac.uk/bitstream/2438/6360/1/FulltextThesis.pdf