MCAT Physics and Math Review

Chapter 11: Reasoning About the Design and Execution of Research

Introduction

In the modern world, there are standard places to search for the answers to questions we have: encyclopedias, academic journals, online databases, and other publications. By perusing current research on a topic, we can figure out whether someone else has already asked and answered our question. This is just as true for scientists and other professionals. In many cases, our searches may take us in different directions. This may be as simple as finding additional resources that confirm the answers to our questions; however, research is often more complicated than that. We may find conflicting answers and have to perform critical analysis to determine which data set (and conclusion) was obtained in the most legitimate, unbiased way. Other times, we’ll have to find the answers on our own through experiment or observation and data analysis.

In order to generate a consistent body of knowledge, the ways in which scientists generate and search for information must be orderly and uniform. In this chapter, we will discuss the premise of basic science, biomedical, and social sciences research. Our examination will include the necessary criteria for causality, different types of error, and the ethical implications of human subjects research. These research methods are core skills that the MCAT tests—in fact, they constitute one of the four Strategic Inquiry and Reasoning Skills on the exam. In addition, their importance will last for the rest of your medical career. As a physician, you will constantly be seeking answers in research to determine prognoses, assess the appropriateness of a treatment modality for a given patient, and answer patients’ questions. You may be a researcher yourself in a basic science, clinical, or translational setting. Regardless of your path, evaluating research is critical to the progress of all fields of medicine and will be a key component of your life as a physician.

11.1 The Scientific Method

The basic paradigm for all scientific inquiry is the scientific method. The scientific method is a set of steps that defines the appropriate order of events to structure and carry out an experiment. As such, the scientific method is the established protocol for transitioning from a question to a new body of knowledge. The steps in the scientific method are:

1.    Generate a testable question. This usually occurs after observing something anomalous in another scientific inquiry or in daily life.

2.    Gather data and resources. Think back to our introduction; this is the phase of journal and database searches and compiling information. At this step, we as scientists must be careful to look for all information, not just that consistent with our views.

3.    Form a hypothesis. A hypothesis is the proposed explanation or proposed answer to our testable question. It is often in the form of an if–then statement, which will be tested in subsequent steps.

4.    Collect new data. This step results from either experimentation, which involves manipulating and controlling variables of interest; or observation, which often involves no changes in the subject’s environment.

5.    Analyze the data. Looking for trends and performing mathematical manipulations will often solidify the connections between variables.

6.    Interpret the data and existing hypothesis. Consider whether the data analysis is consistent with the original hypothesis. If the data is inconsistent, consider alternate hypotheses.

7.    Publish. Publication provides an opportunity for peer review; a summary of what was done during all six prior steps should be included in the publication.

8.    Verify results. Most experiments are repeated to verify the results under new conditions.

BRIDGE

It is easy to focus on research that agrees with our expectations or opinions, and to ignore research that goes against them. This is an example of confirmation bias at work.

Specific types of biases are discussed in Chapter 4 of MCAT Behavioral Sciences Review and later in this chapter.

MCAT EXPERTISE

The MCAT will most often test experimental or logical errors during research. Pay particular attention to the scientific method now in order to recognize each area in which an error may occur.

Formulating a testable question often presents students with a challenge because we tend to overreach, creating all-encompassing broad questions; however, in order to form a good testable question, it must be restricted to a relatively narrow area. The same is true of our hypotheses. One might wonder Why do hot objects cause injury? This is not a testable question. In fact, most questions that begin with Why are too broad to be testable through a single experiment. In this case, a better, more testable question could be How do epithelial cells respond to heat in vivo? Even this question is likely too broad for a single experiment, but it is testable, and we can form related hypotheses. One possible hypothesis would be: if heat is applied to in vivo epithelial cells, then those cells will lyse. Pay attention to the format of the hypothesis, as the if–then format ensures that it is testable. We will examine other components of the scientific method as they pertain to basic science research, biochemical and biomedical research, and social science research in the relevant sections.

THE FINER METHOD

The FINER method for evaluating a research question is a method to determine whether the answer to one’s question will add to the body of scientific knowledge in a practical way and within a reasonable time period. The FINER method asks five questions to make this determination.

·        Is the necessary research study going to be feasible? A question about the response of chemosynthetic bacteria to a particular antibiotic requires access to chemosynthetic bacteria. If the scientist cannot obtain the necessary supplies, then the research is not feasible. Financial or time constraints, or the inability to gather enough subjects are also feasibility concerns.

·        Do other scientists find this question interesting? This is somewhat subjective, but if there is little interest in the outcome of a particular research question, then the research will have little utility.

·        Is this particular question novel? If someone has asked this question before, and answered it to the satisfaction of a peer-reviewed journal, then it’s now in the confirmatory stages of the scientific method. Barring any anomalies, asking this question again isn’t likely to gain new knowledge.

·        Would the study obey ethical principles? Just because we are capable of carrying out a research study does not mean it is ethically or morally acceptable. If there’s an ethical or moral reason not to perform a study, this should dissuade researchers from carrying out the study just as much as an inability to secure funding.

·        Is the question relevant outside the scientific community? The more people that the research will impact in everyday life, the more important it usually is. There are exceptions, of course—many people would agree that curing a rare fatal illness is more important than improving the odor of a popular perfume, although a much larger group may be impacted by the latter study.

MCAT Concept Check 11.1:

Before you move on, assess your understanding of the material with these questions.

1.    Rank the following research questions from 1 (best) to 3 (worst) using the FINER method and explain your rationale:

·        How long does it take for the Earth to complete one revolution around the Sun?

·        How do medical errors relate to sleep deprivation of medical residents?

·        What is the average lifespan of bacteria in Martian rocks?

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2.    Errors or biases during publication of results are most likely to affect which stages of the scientific method?

3.    True or False: Most people with hepatitis C acquired it through IV drug use is an example of a well-formatted hypothesis.