Instructions: Please read through the following description of the scientific method, watching videos, and following links where indicated. After the lab introduction, you will get to Lab Activity 1. As you complete the activities and reflection questions, please fill out your answers on the answer sheet provided in Blackboard. All activities and questions you need to complete have been highlighted. You may submit them as digital assignments, or as hard copies in class.
The scientific method is a process for empirically testing possible answers to questions about natural phenomena in ways that may be repeated and verified. The questions arise from our observations of the world around us. The answers that result from the testing are added to the body of knowledge we have about the natural universe. Scientific explanations are always subject to updates and modifications based on further testing.
The scientific method generally has the following steps:
- Observation. A researcher may make observations directly from nature with his or her own senses, or from the written words of other investigators who have published scientific articles that are available in university libraries. Either way, the observed phenomenon must be repeatable – something that can be observed more than once.
- Research. Collect enough data about your observation so that you can create an accurate, informed hypothesis.
- Hypothesis. A hypothesis is a proposed explanation for the observed phenomena. You must formulate your hypothesis based on the research you’ve collected on your observation. Hypotheses provide a general answer statement to your observation question.
- Experiment. All hypotheses must be testable. The testing, or experimental, stage produces more information (data) about the original observation that may or may not support the hypothesis. This stage is often repeated multiple times, by different researchers, who may not have been involved in the original observations.
- Conclusion. After running your experiment, you need to form a conclusion or explanation.This may or may not support the original hypothesis. It is based on your analysis of the data collected and tested in your experiment and has some validity, or support.
- Disseminate Information. Since an experiment must be repeatable, you need to share your conclusions with the greater community.
Sometimes, repeated testing by numerous researchers working in many different countries all support the same conclusion and stand the test of time. In these cases, the validity of the results is generally accepted by the scientific community and the conclusion may be considered a scientific theory. All scientific theories have been rigorously and exhaustively tested and are supported by a significant body of data.
Experimental or Research Design.
Experiments or observations are used to test hypotheses. Specifically, they test the relationships between two (or more) variables. Often, scientists develop “Test Implications” or a series of “if…then” statements for testing with specific observations.
There are two ways of conducting scientific tests:
- Controlled experiments. These occur when the investigator designs an experimental situation, usually in a laboratory, allowing the researcher to alter one variable and see what effect it has on the other variable. You can learn more about controlled experiments here: Controlled Experiment
- Natural ‘experiments’ or observations. The researcher has little or no control over any of the variables in natural experiments, but uses observation to test generalizations. Such experiments are common in animal behavior studies, where an investigator spends a considerable amount of time in the field observing subjects and taking careful notes of their observations.
Inductive vs. Deductive Reasoning
In analyzing data acquired from observations and experiments, there are two types of logical reasoning that can be used—inductive or deductive reasoning.
- Inductive Reasoning. In its simplest form, this reasoning strategy uses specifics to induce a generality. In other words, using specific pieces of data—single observations—to arrive at a general conclusion. For example, by thinking about phenomena such as how apples fall and how the planets move, Newton induced a theory of gravity.
This is the form of reasoning most suited to biological anthropology and almost always, the only form of reasoning used in biological anthropology. This is because of the data that we have available to work with in this field. Biological anthropologists are able to observe just a few groups of primates or collect one bone from an ancient hominid. These are specifics.
- Deductive Reasoning. In its simplest form, this reasoning strategy uses general principles to deduce specifics. An example of this would be 19th century physicists applying Newton’s theory (general principle) to deduce the existence, position, and orbit of Neptune (specific conclusions) from observations of Uranus’s orbit (specific data).
We are very rarely able to use deductive logic in anthropology because our general principles/theories are all derived from specific evidence (ex. All of the early hominid fossil finds are bipedal. Thus, early hominids were bipedal). Every time we find new specific data (like a new fossil) we have to adjust these general principles. As such, biological anthropologists cannot deduce that just because ‘early hominids were bipedal’, every hominid fossil find will be of a bipedal specimen. The next one (specific data) might not be, and thus make us rethink our general principle or bipedality.
Now you are ready to test out your powers of employing the scientific method. Four observations that have been made by a physical anthropologist are listed below. Please choose one of the observations, come up with a hypothesis to explain the observation, and design a testable experiment. Note: you have been awarded a fantastic grant from the National Science Foundation for your research, so money is no object here.
- In most humans, the right humerus (upper arm bone) is larger than the left humerus.
- In 2011, students on the UofSC campus noticed that the noise produced by cicadas was much louder than previous years, and has not been as loud since.
- Orangutans living in zoos tend to be overweight when compared to their wild counterparts.
- A species of tree frogs comes in shades of brown and green. In some places, brown frogs are more common, and in others green frogs are more common.
- Which observation are you analyzing?
- Hypothesis. What explanation can you come up with to explain the phenomena observed?
- Design your experiment. How would you test whether or not your hypothesis is correct?
Now that you’ve practiced explaining someone else’s observations, you’re ready to test the process out on your own. Look around your house (or wherever you happen to be completing this lab) and note an observation or question that you want to test. These do not have to be large-scale phenomena—simple, testable observations will do. Examples: my dog tries to eat meat off my plate but not fruit, white socks get dirty faster than black socks, my baby sister cries if everyone leaves the room, etc. Then, fill out the scientific method flow chart on the next page and answer the reflection questions. In this activity, you will need to actually run your experiment, not just describe it. (NOTE: depending on your software capabilities, you can either type your answers directly in the boxes or create new headings and list all your answers below.) You may need to reference the short YouTube video above for explanation of some of the terminology.
End of lab reflection questions
- In designing your experiment/research design, did you take ethical issues into account? If not, how might ethical concerns have caused you to change your experiment design?
- Did your data support your hypothesis? If not, how might you adjust your hypothesis in a second round of inquiry?
- Were your research designs repeatable? Could someone else have conducted the same experiment and obtained the same results?
- Why do you think it is important to follow a strict methodology in conducting scientific experiments?
- Do you have any questions about the scientific method, or this lab in general?