The steps in the scientific method guide researchers in planning, conducting and interpreting research studies. However, it is important to recognize some limitations of such a "disciplined inquiry" approach. For example, it cannot provide answers to questions that seek to determine what should be done. Some questions are not answerable by research studies because collecting data will not resolve the question, or because the answer is also influenced by personal philosophy, values and ethics. Secondly, research studies can never capture the full richness of the individuals and sites that they study. Although some research approaches lead to deeper understanding of the research context than others, no approach provides full comprehension of a site and its inhabitants. No matter how many variables one studies or how long one is immersed in a research context, there will always be other variables and aspects of a context that were not examined. Thus, all research gives us a simplified version of reality, an abstraction from the whole. Thirdly, there are limits to our research technologies. Our data collection instruments and the available theories are primitive in comparison to the instruments and theories of, say, medicine. Our measuring instruments always have some degree of error. The variables we study are often proxies for the real behavior we seek to examine. For example, we use a multiple choice test to assess a person's values. Finally, educational research is carried out the co-operation of participants who agree to provide researchers with data. Because researchers deal with human beings, they must consider a number of ethical concerns and responsibilities to the participants. For example, they must shelter participants from real or potential harm. They must inform participants about the nature of the planned research and address the expectations of the participants.