QUANTITATIVE: research produces data in numerical form, e.g. IQ score, speed estimate etc. QUALITATIVE: rich data that is highly descriptive, research produces data in the form of words, such as number of people, number of cars etc.
Advantages:
rich data
good for investigating complex situations
tends to be more experimentally valid if the individual studied remains in their natural environment
study topics that are unquantifiable
Disadvantages:
time consuming
tons of data therefore analysis can be problematic
researcher immerses themself too much
interpreting results can be affected by researcher