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.
Characteristics of Scientific Research. When researches progress to a certain degree, turning over to think about them in time will contribute to advance their process and make them develop healthily in correct direction. Therefore, let's have a look into the characteristics of our work macroscopically and generally.
One of the key factors in developing and testing scientific theories is the identification and operational definition of the variables that describe phenomena observed in the real world. Variables are measured in a research study, and they can have more than one value. There are several types of variables of interest to the researcher. Independent variables are stimuli that are manipulated in order to determine their effect on the value of dependent variables.