Click on the following links. Please note these will open in a new window.

Pew Research Center Internet, Science & Tech Project
Click on “Datasets” at the above site to get current statistics on Internet use and on the characteristics of Internet and other technology users.

Pew Research Center U.S. Politics and Policy
Click on “Methodology” for discussions of survey sampling.

Research Randomizer
One online site for generating random numbers.

Sample Size Calculators

NSS Sample Size Calculator
Sample Size Calculator
Sample Size Calculator
The above three websites will help you calculate a sample size given your inputs such as standard error, confidence interval, and homogeneity of the sample. Commercial survey sites such as SurveyMonkey can also help with sample size calculations.

StatPac
A commercial survey software site with tutorials on sampling and other survey procedures.

Survey Sampling International
A commercial site providing sampling services internationally

WebSM
A European site on web survey methods and sampling.

World Association for Public Opinion Research (WAPOR)
Provides a code of professional ethics and practices at http://wapor.org/wapor-code-of-ethics/.

Council of American Survey Research Organizations (CASRO)
Provides basic information on surveys and survey sampling.