What is the difference between quantitative data and qualitative data? As a marketer,how should you utilize both types of research?

Qualitative data are those data that are developed from observation or via textual,verbal,and open-ended responses methods.Qualitative data tend to be subjective and imprecise and are not easily compared or generalized across customers,but qualitative data can provide invaluable depth and vividness.Quantitative data are responses that are provided or can be summarized numerically,and quantitative methods are conducive to statistical analysis,enabling generalization of results across larger groups.The ability to compare data across customers,for example the ability to compare customers across time or across segments,and the ability to "generalize" to all customers in a target population (a segment or a market)support the use of quantitative data in many market research applications.The general flow should be from qualitative research in small,nonrandom samples toward quantitative methods in larger and random samples.