A study in which the participants are assigned by chance to separate groups that compare different treatments; neither the researchers nor the participants can choose which group. Using chance to assign people to groups means that the groups will be similar and that the treatments they receive can be compared objectively.
A clinical trial in which the participants are not assigned by chance to different treatment groups. Participants may choose which group they want to be in, or they may be assigned to the groups by the researchers.
A research design in which several age cohort groups are compared at several times of measurement; essentially, a number of longitudinal studies, each starting with a different age group.
Single Subject Experimental
aims to examine whether an intervention has the intended effect on an individual, or on many individuals viewed as one group. The two most common single subject research designs are the A-B-A-B design, and multiple baseline design
A study in which participants, processes, or systems are studied over time, with data being collected at multiple intervals. The two main types are prospective studies and retrospective studies.
Match up patients with same factors. One patient gets controlled other experimental. Problem is matching criteria