1 Nature of Science
Andrea Bierema
Learning Objectives
- Identify aspects and misconceptions regarding the nature of science and scientific inquiry.
- Explain how the commonly taught “scientific method” aligns with the setup of a research paper.
- Describe the processes of science.
- Identify scientific research questions.
- Construct scientific observations and inferences.
- Describe the main parts of a scientific argument.
- Explain how evidence, including graphs, supports a claim.
- Given a description of an investigation, describe the type of study, the research question, and control and experimental variables, when appropriate.
An Introduction to the Nature of Science
To understand what science is, just look around you. What do you see? Perhaps your hand on the mouse, a computer screen, papers, ballpoint pens, the family cat, the sun shining through the window, etc. Science is, in one sense, our knowledge of all that: all the stuff that is in the universe from the tiniest subatomic particles in a single atom of the metal in your computer’s circuits to the nuclear reactions that formed the immense ball of gas that is our sun, to the complex chemical interactions and electrical fluctuations within your own body that allow you to read and understand these words. But just as importantly, science is also a reliable process by which we learn about all that stuff in the universe. However, science is different from many other ways of learning because of the way it is done. Science relies on testing ideas with evidence gathered from the natural world.
Given the way that science is often taught—memorizing facts from a thick textbook based on research done decades ago and completing lab activities in which there is one known answer—many students have misconceptions about what science is and how it works. Complete the following interactive to learn more about the real side of science!
Exercise
Scientific Practices
Exercise
The above quiz mentioned that there really is no one scientific method. So why is “the scientific method” so often taught?
Simply put, it is easier to follow something in an organized, familiar format than to follow along the actual process of any given investigation. This is why the standard setup of a scientific article is organized in a similar way as “the scientific method” and likely why it is often taught in grade school (and even college).
See the chapter “Information Communication” to learn more about scientific articles.
Science Flowchart
As you learned from the activity above, scientists do not follow one Scientific Method. Rather, science is complex, but some shared practices among scientists (not just biologists, but all scientists) can be represented as a flowchart. Notice in the flowchart below, for instance,
- it is non-linear; every study is unpredictable and follows a different path,
- the research is not “done” after one investigation. Results often lead to new questions or new ways to investigate a similar question, and
- one of the main elements is “Community Analysis and Feedback.” Science is a social endeavor and scientists talk to each other about their research before, during, and after an investigation is done and even published.
Exercise
At first glance, scientific practices, as demonstrated in the science flowchart, might seem overwhelming. Even within the scope of a single investigation, science may involve many different people engaged in all sorts of different activities in different orders and at different points in time—it is simply much more dynamic, flexible, unpredictable, and rich than many other representations. Let’s break it down by looking at an example. The video below explains how an investigation of past climate change fits into the elements of the science flow chart.
For closed captioning or to view the full transcript see the video on YouTube. or click on the “YouTube” link in the video.
Testable Research Questions
What makes something science? The checklist below provides a guide for which sorts of activities are encompassed by science, but because the boundaries of science are not clearly defined, the list should not be interpreted as all-or-nothing. Some of these characteristics are particularly important to science (e.g., all of science must ultimately rely on evidence), but others are less central. For example, some perfectly scientific investigations may run into a dead-end and not lead to ongoing research. Use this checklist as a reminder of the usual features of science. If something doesn’t meet most of these characteristics, it shouldn’t be treated as science.
- Science focuses on the natural world
- Science aims to explain the natural world
- Science uses testable ideas
- Science relies on evidence
- Science involves the scientific community
- Science leads to ongoing research
- Science benefits from scientific behavior
Example
Most of us have probably wondered how other animals think and experience the world (e.g., is Fido really happy to see me or does he just want a treat), but can that curiosity be satisfied by science? After all, how could we ever test an idea about how another animal thinks? In the 1940s, psychologist Edward Tolman investigated a related question using the methods of science. He wanted to know how rats successfully navigate their surroundings—for example, a maze containing a hidden reward. Tolman suspected that rats would build mental maps of the maze as they investigated it (forming a mental picture of the layout of the maze), but many of his colleagues thought that rats would learn to navigate the maze through stimulus-response, associating particular cues with particular outcomes (e.g., taking this tunnel means I get a piece of cheese) without forming any big picture of the maze.
Here’s how Tolman’s investigation measures up against our checklist:
So is it science? Though less stereotypically scientific than splitting atoms, this psychological research is very much within the realm of science.
Exercise
As seen in the above exercise, only testable ideas that are regarding the natural world are within the purview of science.
Additional Example
Some topics initially appear to be scientific, but actually are not. For example, the Intelligent Design movement promotes the idea that many aspects of life are too complex to have evolved without the intervention of an intelligent cause—assumed by most proponents to be a supernatural being, like God. Promoters of this idea are interested in explaining what we observe in the natural world (the features of living things), which aligns well with science aims. However, because Intelligent Design relies on the action of an unspecified “intelligent cause,” it is not a testable idea. The Understanding Science website has more information.
Observations and Inferences
Figure. A collage of examples of how scientists can make observations. Hover over each image for a description. All images from pexels.com
We typically think of observations as having been seen “with our own eyes,” but in science, observations , humans cannot directly sense many of the phenomena that science investigates (no amount of staring at this computer screen will ever let you see the atoms that make it up or the UV radiation that it emits).
What do we do once we have these observations? The next thing is to infer what those observations could mean concerning our research question. This is where prior knowledge and creativity can come into play. What we believe the observations mean is called an “inference.”
Exercise
Try this exercise to practice identifying observations, inferring what those observations mean, and developing conclusions. Although the “investigation” is not science-based, the skills that you will practice model what scientists do.
Scientific Arguments
We can extend this idea of observations and inferences to scientific arguments.
In this case, the term argument refers not to a disagreement between two people, but to an evidence-based line of reasoning; so scientific arguments are more like the closing argument in a court case (a logical description of what we think and why we think it) than they are like the fights you may have had with siblings.
There are three main components to a scientific argument:
In the figure above, click on the information (“i”) icon to learn more about the main components of a scientific argument.
Example
Below is an article with the parts of the argument labeled.
Testing Ideas
Ultimately, scientific ideas must not only be testable but must actually be tested—preferably with many different lines of evidence by many different people. This characteristic is at the heart of all science. Now that we have learned about the complexity of science as a process, let’s explore some of the common ways in which scientists test ideas.
The table below describes some general aspects of the selected types of study: experimental studies, observations studies, and modeling studies. “Experiment” is broken down into three main types: true experiments, quasi-experiments, and natural experiments. One of the main aspects that distinguish true experiments from all other studies is having an experimental group) and a control group).
Types of Research Studies
| Type of Study | Does it follow the nature of science tenants explained in this chapter (e.g., science is somewhat subjective)? | Does it examine possible treatment effects? | Does the investigator perform some type of manipulation (e.g., introduce an experimental variable)? | Does it use both a control group and experimental group(s)? | Does it test for cause and effect relationships? | Is the goal of the study to describe a sample's characteristics? | Will the results and/or conclusion include images or drawings? | Example_Research_Questions |
|---|---|---|---|---|---|---|---|---|
| True Experiment | Yes | Yes | Yes | Yes | It may | No | It may | How does the presence of a cowbird (brood parasite) affect foraging behavior of yellow warbler parents? Place a taxidermy cowbird near some yellow warbler nests; observe behavior of birds with and without the cowbird. |
| Quasi-Experiment | Yes | Yes | Yes | No | It may | No | It may | How does temperature affect honey production in honeybees? (create treatment groups exposed to different temperatures, keeping everything else constant) |
| Natural Experiment | Yes | Yes | No | It may have a control | It may | No | It may | How does the size of an island affect the number of plant species? (examine islands with similar environments) |
| Observational Study | Yes | No | No | No | No | It may | It may | How has biodiversity of coral reefs changed in the last 100 years (compare data collected across multiple decades) |
| Modeling Study | Yes | No | No | No | Yes | No | It may | How are wildcat species evolutionarily related to each other (use programs to compare genomes and create a phylogenetic tree) |
A list of different types of research studies and their corresponding characteristics.
To learn more about these types of studies, click on the headings below:
Constants
Ideally, investigations also involve keeping as many other factors as constant as possible to better explain the outcome. This is particularly true in experiments. In experiments, ideally, just one variable will vary between the groups (the experimental variable), and everything else will remain constant (often referred to as “controlled variables”). For instance, if investigating the effects of temperature on honey bees, then the rest of the environment, such as the amount of space or sunlight, should remain the same across the groups. In a natural experiment, though, this is not possible for all variables and this lack of control needs to be considered when examining the results of the study (one of the downfalls of a natural experiment).
In modeling studies, the model is not an exact replica of the system of interest. Rather, it only focuses on the possible causes of the observed phenomenon (i.e., the effects of interest). Although the aspects of the system that are considered irrelevant are not true “controlled variables,” it is, nonetheless, important to consider when developing models.
Controlling variables during an observational study is usually not possible, or even desired as the intention is to describe relationships or patterns.
Are model organisms scientific models?
A model organism is a non-human species that has been widely studied, usually because it is easy to maintain and breed in a laboratory setting and has particular experimental advantages. For example, they may have particularly robust embryos that are easily studied and manipulated in the lab, which is useful for scientists studying development. Or, they may occupy a pivotal position in the evolutionary tree; this is useful for scientists studying evolution.
If a study uses a model organism, is it a modeling study? The answer may seem like an obvious “yes”, but consider how modeling organisms are used. For instance, what if the modeling organism is used in an experimental design in which some individuals are part of an experimental group and others are in a control group. The purpose of doing the research may be ultimately to predict how the treatment may affect humans, but what is the research question? The research question is “how does treatment x affect this model species?” Scientists then use that information to infer how the treatment might affect humans, but it cannot by itself actually answer the question of how humans will be impacted. Instead, it is inferred that humans may be impacted by prior research that connects physiological similarities and differences between the model species and humans.
Therefore, when asking if a study is a modeling study, do not assume it is because it is using a model species. Rather, consider what the research question is, not just the general purpose of doing the research.
Exercise
Now try applying what you have learned about scientific research to a couple of investigations!
For this first investigation, learn how using both ancestral knowledge and western science more greatly informs research.
To view the full transcript see the video on YouTube. Or click on the “YouTube” link in the video.
For closed captioning or to view the full transcript see the video on YouTube. Or click on the “YouTube” link in the video.
Attributions
This chapter is a modified derivative of the following articles:
Understanding Science. 2020. University of California Museum of Paleontology. 11 June 2020 <http://www.understandingscience.org>.
“What are Model Organisms?” by Yourgenome, Genome Research Limited is licensed under CC BY 4.0 License.
Our knowledge of the natural world and the process through which that knowledge is built. The process of science relies on the testing of ideas with evidence gathered from the natural world. Science as a whole cannot be precisely defined but can be broadly described by a set of key characteristics. To learn more, visit A science checklist.
In science, an observation or experiment that could provide evidence regarding the accuracy of a scientific idea. Testing involves figuring out what one would expect to observe if an idea were correct and comparing that expectation to what one actually observes.
Test results and/or observations that may either help support or help refute a scientific idea. In general, raw data are considered evidence only once they have been interpreted in a way that reflects on the accuracy of a scientific idea.
All the components of the physical universe — atoms, plants, ecosystems, people, societies, galaxies, etc., as well as the natural forces at work on those things. Elements of the natural world (as opposed to the supernatural) can be investigated by science.
An idea that is often thought to be true but is actually incorrect.
Capable of being tested scientifically. An idea is testable when it logically generates a set of expectations about what we should observe in a particular situation. Ideas that are not testable cannot be investigated by science.
Not of the natural world. Supernatural entities, forces, and processes cannot be studied with the methods of science. To learn more, visit What's natural?
To note, record, or attend to a result, occurrence, or phenomenon. Though we typically think of observations as having been made "with our own eyes," in science, observations may be made directly (by seeing, feeling, hearing, tasting, or smelling) or indirectly using tools.
A logical description of a scientific claim and the evidence for or against it. In everyday language, an argument usually means a verbal disagreement, but here we use another meaning of the term: a reasoned case for or against a particular viewpoint. Scientific arguments generally have a few basic components: What is the claim? What is the evidence that supports the claim, and why does the evidence support that claim?
A scientific test that involves manipulating some factor or factors in a system in order to see how those changes affect the outcome or behavior of the system. Experiments are important in science, but they are not the only way to test scientific ideas.
In science, the term model can mean several different things (e.g., an idea about how something works, a physical model of a system that can be used for testing or demonstrative purposes, or a mathematical model, which is set of equations that indirectly represents a real system). These equations are based on relevant information about the system and on sets of hypotheses about how the system works. Given a set of parameters, a model can generate expectations about how the system will behave in a particular situation. A model and the hypotheses it is based upon are supported when the model generates expectations that match the behavior of its real-world counterpart. Modeling often involves idealizing the system in some way — leaving some aspects of the real system out of the model in order to isolate particular factors or to make the model easier to work with computationally.
In scientific testing, a group of individuals or cases that receive the experimental treatment or factor. Experimental groups can be contrasted with control groups.
In scientific testing, a group of individuals or cases matched to an experimental group and treated in the same way as that group, but which is not exposed to the experimental treatment or factor that the experimental group is. Control groups are especially important in medical studies in order to separate placebo effects from outcomes of interest. Control groups are sometimes also called control treatments or simply controls. This can be confusing since this use of the term is slightly different from what we mean when talking about controlled variables.
In scientific testing, to keep a variable or variables constant so that the impact of another factor can be better understood.
A non-human species that has been widely studied and is used in experiments to make predictions on how variables may impact humans.
To figure out through logical reasoning. Inferences are often based on established knowledge and/or assumptions.
