Key differences between qualitative and quantitative research methods include their analytical objectives, the questions they employ, the data instruments they use, the forms of data they produce, and most importantly, the degree of flexibility within the study design. The objective of quantitative research methods are primarily to predict casual relationships, describe characteristics of a population, and to quantify variation, whereas the purpose of qualitative research methods include to describe and explain relationships, to describe group norms, and to describe variation. Typically, quantitative research methods use closed-ended questions, such as a multiple choice, true/false, or yes/no type answer format; dissimilarly, qualitative research methods use open-ended questions that require the participant to provide an in-depth response. If one is not given, asking “why?” or “how?” can provoke the participant to expand their answer. The instruments used in quantitative research methods use a more rigid style of eliciting and categorizing responses to questions, while the instruments used in qualitative research use more flexible, iterative style of categorizing responses to questions.
The data received in quantitative research methods is primarily numerical statistics, such as “78% of all women wear makeup,” while the data format of qualitative research methods are textual, i.e. “most women wear makeup.” The most important difference between quantitative and qualitative methods is their degree of flexibility. Quantitative methods are fairly inflexible; the researcher asks all the participants identical questions, thus eliminating suggestibility in their questions. Qualitative methods, being more flexible, allow greater spontaneity in their methods of experimentation. The open-ended questions are not always worded the same way, and participants are allowed to elaborate as much as they please, rather than restricting them to just yes/no answer choices.
To conclude, there are many differences between qualitative and quantitative research methods, differences that a researcher must be aware of before they commence an experiment. One advantage of the inflexibility of the qualitative method of experimentation is the researcher’s ability to directly compare the responses given by the subjects. Furthermore, the data format received is typically more intellectually sound; the rigid format of a number is much more stable than a relative term. For example, when one hears “most women wear makeup,” when one hears the word “most,” a number such as 78% may be the number they think of, but to someone else, the word “most” may mean a number such as 98%. However, qualitative research methods are typically more culturally salient, unanticipated by the researcher, and more explanatory in nature.