Qualitative Methods - Qualitative research is designed to explore the human elements of a given topic, where specific methods are used to examine how individuals see and experience the world. Qualitative methods are best for addressing many of the why questions that researchers have in mind when they develop their projects. Qualitative approaches are typically used to explore individuals’ thoughts, feelings, or interpretations of meaning and process.
Quantitative Methods - Quantitative approaches are appropriate for examining who has engaged in a behavior or what has happened, but these techniques are not designed to explain why certain behaviors occur. Quantitative methods involve the collection of data in numerical form from ratings, incidents, scores, scales, etc.
Mixed Methods - The combined use of both quantitative and qualitative methodoligies to address a single research question.
From Sage Research Methods Online.