In this module, we're going to begin our adventure into scientific inquiry with the ultimate goal of learning what it means to explore something scientifically and learning to decipher between what is scientific and what is not. We'll spend a little bit of time on this because it can actually be quite tricky to decipher science from pseudoscience, and doing so requires both knowing what to look for and taking the effort to dig deeper, which isn't always easy. Along the way, we'll learn about other methods of inquiry, what their roles are, and why they are not scientific. This will lead us toward our ultimate goal of learning the research process. On that note, let's put this in context. We're here to learn about the research process and how research is conducted. But the goal of the research process, as we've seen in the previous lessons, is to provide explanations through a process of scientific inquiry. In order to understand the research process, we must first have a strong grasp for what scientific inquiry entails. Let's begin by asking a basic question. If we seek explanations through scientific inquiry, what makes an explanation scientific? Well, it turns out we can identify seven specific traits of a scientific explanation. This lesson will be all about exploring those seven essential characteristics. Scientific explanations are empirical, rational, testable, parsimonious, general, tentative, and rigorously evaluated. Now, it's okay if you don't know what all of these terms mean or why they apply to scientific explanations. We're going to spend a little time going through each of them. But it's critical to understand that in order for an explanation to be scientific, it must possess all of these characteristics. Let's dig in. The first characteristic is that a scientific explanation must be empirical. Empirical means that it's based on objective and systematically observed evidence. Note that we say our observations must be objective and systematic. This is intended to take our biases, feelings, beliefs, and intuitions out of the picture. These can serve to mislead us. Instead, scientific observations are often made under conditions that are carefully controlled to remove subjectivity, and it must be possible for others to verify these observations. Secondly, a scientific explanation must be rational. In other words, the explanation must follow logically from the evidence. While perhaps philosophical, the notion of logic is based on the process of making valid inferences, as we'll see in later lessons when we discuss the more mathematical aspects of uncertainty and research. The scientific method is based on a process of inferring an explanation from evidence and reason. A simple way to think about this though is that our explanation must be consistent with known facts. Next, our explanation must be testable. That is, we should be able to verify the explanation through additional observations. While we construct an explanation based on some initial observations, we should be further able to test it by making additional observations. This may lead us to make predictions about what should occur under conditions that we haven't previously observed. If we fail to observe what our explanation predicts, this should lead us to question our explanation. Finally, we should be able to conceive of cases that might disprove our explanation and test to the explanation against these cases. Perhaps the most difficult characteristic to understand is that a scientific explanation should be parsimonious. To be parsimonious means to be stingy or frugal. In the context of scientific explanations, this means that our explanation should be as simple as possible, requiring complexity only where it is strictly necessary. Therefore, we want explanations that don't require us to make assumptions or follow long complex arguments in order to hold it valid. As Einstein famously said, everything should be made as simple as possible, but not simpler. At the same time, a scientific explanation should be general. That is, a good scientific explanation will apply broadly and will not be true only under very specific conditions. Next, and this one is arguably the most important, is that a scientific explanation must always be tentative. When we make a scientific explanation, we must be able to accept the possibility that we're wrong. If we cannot accept this simple possibility, then we violate the most fundamental of scientific principles. There are countless examples in history of scientific hypotheses that prove to be incomplete, faulty, or even downright wrong. For example, for a very long time, it was widely accepted that light must travel through a medium, much the way sound does. This medium was known as the luminiferous aether. But this hypothesis was definitively disproven by the Mickelson Morley experiment in 1887. If scientists had remained adamant about this hypothesis and it had failed to question it, we would be living in a darker world today. A less extreme example is one that we still teach in college physics today, that is Newton's laws of motion. As we now know, Newton's laws are incomplete. While not entirely wrong, they serve only as approximations for the motion of large objects at small speeds. To describe the real physics of motion requires the rather more intricate theories of general relativity and quantum mechanics. Lastly, scientific explanations must be rigorously evaluated. This means that we're continually aiming to reconsider these explanations and testing them against new evidence. We strive to further expand, or in some cases, narrow their scope or replace them altogether as new, plausible alternative explanations arise. These seven essential ingredients make up the foundation of all scientific explanations. Much of this information has been derived from the textbook shown here, where you can go to learn more. Additional reference materials can be found in the following slides.