Qualitative vs Quantitative

Quantitative methods is using numbers, and evaluating the numbers using standard statistical techniques. The data is characterized with averages, standard deviations, variances, outliers identification among others. Typically opinion data is converted to numbers using a Likert scale. For example any survey that asks you to rank things using "strongly agree", "agree", "neither agree nor disagree" etc. is converting your opinion into numbers, which then can be evaluated using quantitative methods. In theory this type of analysis should be generalizable to broader populations.

Qualitative methods uses descriptions, notes from interactions, and dialogue to create an understanding of the experience. This methodology is relatively foreign to engineering and physical science (chemistry, physics, mathematics) researchers, but is more common in the social sciences. These methods are aimed at understanding experiences, relationships, events or people in general. There is an entire vocabulary associated with qualitative methods just like there is a vocabulary associated with quantitative methods such as variance or standard deviation. The terms are probably less familiar to most engineering faculty and students and the first step in getting involved in qualitative methods is to learn some of the vocabulary such as "narrative inquiry", or "ethnography".

So which is better? Before getting involved in Engineering Education research I was strongly in favor of Quantitative methods. It seemed more objective and generalizable. This may be the case for measurable physical events, such as this force results in this acceleration, however, when doing research that involve people, especially aimed at getting an understanding of their experience, this is not necessarily the case. While the Likert Scale survey may seem objective, depending on how the survey questions are written, a bias can be built into the data.

To push forward advanced in education I believe that a mixed methods of evaluation is needed. The quantitative methods are very useful in understanding student performance on assessment items (exams, quizzes, homework), however, qualitative methods are just as useful at understanding the student experience and impact of the new pedagogy.