Quantitative data analysis or research is an empirical investigation that is very systematic and structured in nature. This kind of research also uses a lot of mathematical investigation hence the term quantitative. There are a lot of numbers involved when gathering quantitative data. The objective of this kind of research is to gather and develop theories and form a hypothesis as to the predicted outcome. These hypotheses are also not always proven but this is the point of research.
Data is gathered in numerous ways such as surveys, questionnaires, and interviews. Sample sizes are also usually large in this kind of research.
Quantitative data is that which can be explained using a number. This number is a measurement usually made by instrumentation but may also be made by counting. Quantitative data is invariably easier to communicate than qualitative data because it is less interpretive, meaning we all can understand what 3.0 mm is versus the term 'small' which is a relative term.