Final answer:
Evidence from a randomized controlled trial is related to experimental research and involves a controlled experiment. Longitudinal research involves tracking participants over time. Both experimental and quantitative research methods rely on well-designed studies to produce reliable and ethical data.
Step-by-step explanation:
Evidence obtained from at least one well-designed randomized controlled trial (RCT) is an example of experimental research. This involves a controlled experiment where participants are randomly allocated to receive different treatments, one of which is usually a standard treatment or placebo. It's a highly effective method to test the efficacy of interventions in Medical and Health Sciences.
Research that involves following a group of research participants for an extended period of time is known as longitudinal research. This method can provide insights into how variables change over time.
Scientific evidence that supports the choice of a research group designation could include a variety of observational or experimental data, emphasizing the importance of using a well-structured research design to address specific hypotheses and reduce the influence of lurking variables.
The principles that guide research can encompass ethical considerations and methodological approaches to ensure that the experimental design provides reliable data and ethical treatment of participants.
Finally, quantitative research involves the use of hard, specific data that can often be replicated in a controlled environment, forming the primary evidence in the case of studies.