The four research approaches are qualitative, quantitative, pragmatic and participatory. Each of these approaches carries unique procedural advantages and disadvantages.
The quantitative method is closely connected to positivist and post-positivist philosophy. It involves the collection of data and its transmission into numerical models that can be assessed and manipulated to reach conclusions about a given experiment or data set. It places a heavy emphasis on objectivity.
Qualitative methodology attempts to probe the latent meaning beneath human behavior. This is accomplished primarily through observation and record-keeping. It is a much more specific model than the quantitative method, focused more intently on gaining information applicable to a given situation. It does not transfer its finding readily to generalized milieus.
The pragmatic approach sets philosophical considerations aside in favor of taking the most readily accessible avenue. It depends on intuitive and educated guesses at which methods will provide the most finely targeted results. It also sometimes blends or uses interchangeably the qualitative and quantitative methods in order to streamline its processes.
Participatory or advocacy models of research are often politically motivated and attempt to include the voices of oppressed or marginalized groups. This method deals with the inherent privilege of the establishment and with ameliorating that privilege through inclusivism.