You ask the following: What is the difference between Taught and Research based PhD?
May be due to an English language problem, your question is not much clear to me. So, my answer can, say, miss the point. I wonder wheter you are asking for the differences between a Ph D based on teaching or based on research. As I see it, a Ph H always requires that we perform a research on a given topic. This topic can be the process of teaching/learning. So, I see no dichotomy in your question because a Ph H dissertion or thesis can be about teaching/learning. I think that your question asks us to say what is better as soon as a student gets his/her Ph H: To teach or to perform research? As I see it, once one gets a Ph D and remains at a college or university, one should teach and resarch at the same time. This aspect notwithstanding, there are, say, teaching-oriented colleges/universities and research-orietend colleges/universities. The former values more teaching than research, whereas the laltter values more research than teaching. As for my case, during my academic career I always taught at both the undergraduate and graduate level and performed empirical and concptual research.
I agree with you . I should have written : PhD by research only OR, PhD by coursework and research.
Sorry, I did not get what you are explaining.
I found similar discussion done a year ago. Please, find the link: https://www.researchgate.net/post/Which_is_better_and_why_PhD_by_research_or_coursework_and_research.
For some countries and in some disciplines, esp. in the humanities, a PhD by research only is often considered to be too narrow a qualification for an academic position that involves substantial undergraduate teaching duties. In fact many schools also require comprehensive exams to ensure that their PhDs have sufficient breadth in the discipline.
I am much in agreement with our colleague Karl Pfeifer's perspective. In my dept.of Psychology a Ph D does is not sufficient enough to to be promoted to the rank order of Assistant Professor. For this to be the case, Ph D students should teach at the undergraduate level and continue to perform research. After that, their work is assessed by the Scientific Committee of the Dept. If this assessment is considered to be positive, those Ph H are promoted to the position of Assistant Professor. In the case of a negative evaluation, Ph D students have to leave the Dept and look for a job outside the University. This is too a demanding procedure. However, I am in favor that Universities want their staff to be higly qualified.