Sample size calculator
The sample size of a market research project is the number of observations or respondents taking part in the project. Typically, a larger sample size leads to increased precision in estimates of various properties of the population. The following tool can be used to calculate what sample size is needed to get the needed precision. An explanation can be found by clicking on the terms used in the calculator.
Confidence level
In statistics, a confidence interval is a particular kind of interval estimate of a population parameter. Instead of estimating the parameter by a single value, an interval likely to include the parameter is given. Thus, confidence intervals are used to indicate the reliability of an estimate. How likely the interval is to contain the parameter is determined by the confidence level or confidence coefficient. Increasing the desired confidence level will widen the confidence interval.
A confidence interval is always qualified by a particular confidence level, usually expressed as a percentage; thus one speaks of a "95% confidence interval". The end points of the confidence interval are referred to as confidence limits. For a given estimation procedure in a given situation, the higher the confidence level, the wider the confidence interval will be.
In market research, often a confidence level of 5% is used.
Source: Wikipedia
Confidence interval
In statistics, a confidence interval is a particular kind of interval estimate of a population parameter. Instead of estimating the parameter by a single value, an interval likely to include the parameter is given. Thus, confidence intervals are used to indicate the reliability of an estimate. How likely the interval is to contain the parameter is determined by the confidence level or confidence coefficient. Increasing the desired confidence level will widen the confidence interval.
A confidence interval is always qualified by a particular confidence level, usually expressed as a percentage; thus one speaks of a "95% confidence interval". For a given estimation procedure in a given situation, the higher the confidence level, the wider the confidence interval will be.
In market research, often a confidence level of 5% is used.
Source: Wikipedia
Population
The population stands for the target group for your market research project. This is not the same as your sample. The sample of a market research project is the number of observations or respondents taking part in the project. The sample is mostly a smaller part of the population. Say you want to perform a client satisfactory research. The company you are working for has 4000 clients. Those 4000 clients form the population. If 300 clients take part in the research project, those 300 form the sample. Typically, a larger sample size leads to increased precision in estimates of various properties of the population.
