Reading in Science
Reading To Understand Evidence and Draw Conclusions
The goal of most scientific experiments is to determine cause and effect—to establish that one factor (variable) influences or determines another. By establishing cause and effect, insight into underlying mechanisms can be gained in a process that digs deeper and deeper into a problem. The process of breaking problems down into smaller problems to assemble highly detailed explanations is called reductionism. Since reductionism drives most of basic scientific research aimed at discovering new things, students need to become conversant with its goals and methods. However, it is helpful to remind them to periodically consider the broader meaning of the highly focused research. The presence of broader motivating questions and context can also help students who are lost in the weeds, or even bewildered by complex and narrowly focused scientific experiments.
Reflect: From an engineering perspective, it’s clear that you can explain how a hybrid car engine works by describing what each of the engine components do. In this case, the hybrid engine is the sum of its component parts. You can also examine the underlying physical and chemical principles that the hybrid engine is based on, such as the storage of electricity in a battery and the principles of combustion, compression, and friction. Consider asking your students to come up with examples of defining and studying the parts to understand the whole. Encourage diverse examples from medicine, ecology, chemistry, physics, and everyday engineering.
Most important scientific discoveries begin with establishing a correlation. But because correlations can be spurious and misleading, they get a bad rap. For example, data may reveal that the majority of speeding tickets go to cars that have license plates ending in an odd number; however, it is clearly unlikely that the odd number license is either causing the driver to speed or the police to issue the citation. The process of going from intriguing observation, to strong correlation while sifting out the bad correlations, to a good case for cause and effect can take a lot of research and generate many research papers. It would be misleading to leave students with the impression that correlations are negative or to be avoided. But it is good to help them see that correlations are not sufficient as scientific explanations of phenomena.
Reflect: Consider developing breast cancer as a case study in correlation and causality for your students. There are many reputable websites with good information and statistics on breast cancer. Breast cancer research features an exemplary mix of important correlations, established causality, and the benefits and limitations of reductionism. Some aspects to explore include: How many cases of breast cancer are reported each year among woman compared to men? How many cases of breast cancer appear sporadically in the population as opposed to appearing to run in the family? What findings have led to vastly improved diagnosis of breast cancer?