Quick Answer. In some rare cases, excessive stress causes bleeding between periods. It is more common that another condition is responsible, such as pregnancy, polycystic ovary syndrome, infection, pelvic inflammatory disease or side effects of medication, according to WebMD.
Using the scientific method, you can repeat the experiment to find out for yourself whether or not the other researcher's assertions are true. This is a key factor that separates science from dogma! The other important part of scientific research is that a hypothesis must be falsifiable. A falsifiable hypothesis or theory is one where an experiment or another discovery can prove it to be wrong, untrue, and false.
Quantitative research. In natural sciences and social sciences, quantitative research is the systematic empirical investigation of observable phenomena via statistical, mathematical or computational techniques.[1] The objective of quantitative research is to develop and employ mathematical models, theories and hypotheses pertaining to phenomena. The process of measurement is central to quantitative research because it provides the fundamental connection between empirical observation and mathematical