Quantitative research gives analysable data, allowing you to examine the responses and opinions of various groups of participants to a survey.
You may, for example want to know if there is any difference in attitude or experience between younger people and older people.
If you need statistically reliable data for each group of participants, you will need to work out the number of interviews in each group which you will then add together to reach the overall sample size.
You can check out how many interviews you need for a set level of statistical reliability by using our Sample Size Calculator.
Quantitative research interviews can be carried out on line, face to face or over the phone.