If we hope to teach students science practices, then we first have to define what we mean by the term. What does it mean to be a capable scientist? How does an expert practice science, and how does a novice student think it should be practiced?
Basically, science practices are the means by which a scientist discovers new truths about the physical world around us. The Rutgers Physics and Astronomy Education Research group, headed by professor of physics education Eugena Etkina, states the following:
“Science practices are ’habits of mind’ of scientists and engineers, things that they do on a regular basis in their work.”
Science practices are simply those things expert scientist do!
Fundamentally, as science educators focused on teaching good practice, our goal is to move students’ views about how science is done from what we call “novice-like” views to “expert-like” views. We want students to do and think about science similarly to how a professional scientist thinks about and carries out their job. Decades worth of research has gone into studying both how experts approach science, and how students think science is done. Not surprisingly, these views and approaches are very, very far apart. How do we take a novice and get them to act more like an expert? Can we teach the types of practices scientists use in their daily work in a classroom environment? What exactly are these science practices?
In this post, I will describe the general consensus from the research literature on what constitutes expert-like science practice. In my book Creating Scientists, I go into more detail and specifically outline how the Next Generation Science Standards deals with science practice. Educated science teachers will probably not be surprised by the types of practices put into place by professional scientists and their views about the discipline; however, they may be surprised by how students view science and its practices.
How do experts practice science?
Over the decades, there has been some debate among science philosophers and historians about what exactly science is and how it is done. The typical science textbook will usually start with a description of the “scientific method,” generally with an illustration similar to that shown in Figure 1.
The scientist makes an observation of a “strange” phenomenon, generates tentative theories, deduces specific predictions to test those theories through experimentation, carries out the experiment, makes a judgement based on the result, and then repeats if necessary. This is what we might call the “traditional” view of what constitutes science practice. This view is so ingrained in the culture of science education, that an internet search on the key words “scientific method” will produce over 9 million results with most leading to pages displaying images similar to Figure 1.1.
In my classrooms, I never show students this science method map, because it is entirely too simple, and will only serve to reinforce their novice-like views. We are going to approach science in a more sophisticated and authentic manner, because all of the research is beginning to show that if we want to excite students and teach them how to actually do real science, then we need to be authentic. They need to learn how to do science by actually doing it, and doing it the way real science is done. Keep these words in mind as we go: “authentic science.”
As a quick example, Figure 2 shows a cyclical representation of the scientific method, taken from the Wikipedia entry.
Science as deduction
What is authentic science? There is some debate on the details, but there is also tremendous agreement about what constitutes authentic science and what practices the scientist uses. The science education theorist Anton Lawson has suggested that scientific reasoning and its practice fundamentally has the more traditional structure from the textbooks, which he describes as being “hypothetico-deductive” in nature. This means we make hypotheses and deduce the consequences. In this view, science is primarily deductive. There are laws from which we deduce results. If the results are shown in reality, then the law is valid, otherwise the law must be revised. The types of abilities needed to carry-out this process include the ability to properly identify and control variables, and proportional, probabilistic, and correlation thinking.
In this area of science practice, students of science must be taught to design, conduct, and evaluate what are called “hypothesis-testing” experiments in the research literature. I am going to refer to them simply as “testing experiments.” You are probably very familiar with the basic structure of the testing experiment, because most traditional laboratory activities we have students complete in our schools can be described as such, specifically within the physical sciences. For example, the middle school student might melt ice in a cup and measure the change in temperature as a function of the mass of the ice to demonstrate the already taught “law” that heat transfer is proportional to the mass. The high school student might use this same data to determine the heat capacity of the material. The student may drop items of varying weight from the bleachers to determine that they truly do fall at the same rate. These are examples where the answer is already known. Typically, the experiment is given to the student, too!
There is no doubt that deductive process is at the heart of much of science practice; however, many practicing scientists, science philosophers, and education theorists and practitioners have concluded that this traditional view of science practice is just too simplistic a model of science alone to describe how science is done. Real, authentic science is much messier than our simple textbook flow chart. Inductive processes are also critical to the successful practice of science. Furthermore, it may even be academically dangerous to imply to our students that the traditional deductive view is all there is to science practice, since this plays to their already existing novice view that science is a collection of facts and equations to reach for when faced with a problem.
There is no real discovery for the student dropping items from the bleachers. It sure is fun, but the student is merely demonstrating a “fact” that they probably already learned in class. The hypothesis was set for them from the beginning, and the task itself dictated. If the teacher does attempt to have students come up with their own hypotheses and experiments, then they will usually find students have a great deal of difficulty without some prior knowledge and coaching. How do scientists come up with hypotheses? How do they come up with experiments that test them? That is the key part missing from our simple scientific method schematic. Without significant attention paid to that process, students can have reinforced their novice view that science is a collection of facts to learn and remember.
Induction in science
Clearly actual scientists do more than just test hypotheses, they must also come up with them. How does that happen? Historian and philosopher Douglas Allchin found that throughout the modern history of science, much of scientific discovery can be described as inductive in nature. What this means is that often scientists have absolutely no clue why or how certain phenomena occur, such that hazarding a guess, or hypothesis, would be of little value. Instead, scientists developed useful tools for identifying regularities, patterns, and associations. Instead of identifying a hypothesis to test, observations can be made where patterns in the resulting data are used to devise a hypothesis. “Proper” science can be done even when limited theory or prior concepts exist to guide initial observations. This type of investigation is called a “hypothesis-generating” experiment, or more simply an “observation experiment.”
Of course, everyone is right! The practice of science requires both deductive and inductive reasoning abilities, and the types of specific practices required to successfully use both to make new discoveries. In general, scientists make observations, identify evidence, generate and test hypotheses, and draw conclusions. We want our students to do all of that, too. I do not ask you to discount the method described in Figure 1 because it does not describe some of what a scientists does. I want you to discount it because it fails to describe all that a scientist does. A traditional deductive-only view of science combined with worksheet labs having pre-existing hypotheses and a checklist procedure will result in a student maintaining an unsophisticated understanding of science practice. We want to expose students to the “messy” side of science, where sometimes we do not know the answers. Sometimes we are wrong, and we have to re-evaluate our thinking. Sometimes we just have to play, twiddling a knob to see how it affects something else and trying to find some pattern.
Metacognition in science
One often overlooked aspect of what a scientist does involves how they think. Psychology and education professor Deanna Kuhn has further enriched our understanding of science practice by looking at how scientists think about their own thinking, or what we call metacognition. My own research and that of my colleagues over the past decade has shown that fundamentally, the major distinction between the novice and the expert is in the way they think about and view science and its practice. In particular, Kuhn suggests that the distinction is most clear by how the individuals coordinate evidence with theory, and through their “epistemological appreciation” of how new knowledge is formed.
The “expert” consistently evaluates their own thinking and utilizes multiple resources towards solving a problem, making an observation, coming up with a hypothesis, and conducting experiments. The “novice” is typically “stuck” in one type of framing and rarely evaluates their own reasoning. Therefore, we find that metacognition, the simple act of thinking about thinking, is also a defining practice of the expert scientist.
So what does a scientist do?
Putting all of this together, we find that the scientist must first know how to observe the world around them, then be able to design controlled observation experiments, recognize patterns within the resulting data, devise a hypothesis or even competing hypotheses based on these patterns, develop testing experiments that could potentially falsify and/or distinguish between hypotheses, carry out the experiment, analyze and evaluate the data, make conclusions, and communicate their finding being ready to incorporate any new evidence. The entire time they are doing all of this, they must constantly self-evaluate themselves, their methods, and their results by constantly looking for errors, bias, and/or better practices.
Basically, science practice looks a lot more like Figure 2.
That is a quite a lot to handle, which is why the expert scientist has gone through extensive schooling, and typically many years of apprenticeship. Obviously, we do not expect our students to leave high school prepared to immediately tackle the great scientific questions of our age. However, we can begin by placing the student on the right path, with those so inclined being ready for more schooling and apprenticeships. The rest will hopefully be better informed citizens with an appreciation of how scientific knowledge is created.
In Creating Scientists, I get more specific about science practice and look at what the NGSS expects students should be able to do with respect to science practices throughout grade school. I define science practices more explicitly, as they are outlined in the National Research Council’s excellent document A Framework for K-12 Science Education. I also examine how science practices are integrated within the Student Learning Outcomes (SLOs) in the NGSS.