The Scientific Method SOME HISTORY ABOUT THE USE OF THE SCIENTIFIC METHOD Observations and no scientific method For centuries, people based their beliefs on their interpretations of what they saw going on in the world around them without testing their ideas to determine the validity of these theories in other words, they didnt use the scientific method to arrive at answers to their questions. Rather, their conclusions were based on untested observations. Among these ideas, since at least the time of Aristotle (4th Century BC), people (including scientists) believed that simple living organisms could come into being by spontaneous generation. This was the idea that non-living objects can give rise to living organisms. It was common knowledge that simple organisms like worms, beetles, frogs, and salamanders could come from dust, mud, etc., and food left out, quickly swarmed with life. For example:

Observation: Every year in the spring, the Nile River flooded areas of Egypt along the river, leaving behind nutrient-rich mud that enabled the people to grow that years crop of food. However, along with the muddy soil, large numbers of frogs appeared that werent around in drier times. Conclusion: It was perfectly obvious to people back then that muddy soil gave rise to the frogs.

Observation: In many parts of Europe, medieval farmers stored grain in barns with thatched roofs (like Shakespeares house). As a roof aged, it was not uncommon for it to start leaking. This could lead to spoiled or moldy grain, and of course there were lots of mice around. Conclusion: It was obvious to them that the mice came from the moldy grain.

A really early scientific experiment One of the first recorded use of the scientific method to conduct an experiment occurred in about 587 BCE. OK, they didnt call it an experiment, but just see if you think this could be an experiment. To give a bit of historical perspective, in 587 BCE the Babylonians under Nebuchadnezzar won a victory over the kingdom of Judah, and the people of Judah were assimilated into the Babylonian empire or at least that was the Babylonian plan. It was the policy of the Babylonians after conquering another nation to do away with those peoples cultural identity by assimilating/absorbing those people into their own culture. Some of the newly conquered people were forced to migrate to other areas of the Babylonian empire, including Babylon itself, while people from other areas of the Babylonian empire

were sent to live and mingle with those of the newly conquered people who were left behind. Young male relatives of the conquered ruling family were often taken to King Nebuchadnezzars palace in Babylon, where they were taught Babylonian history, culture, language, and astrology/science, and in general, assimilated into the lower ranks of Babylonian royalty, serving in various roles within the palace. As part of this assimilation process, these young men were also fed the rich food that was the typical diet in Nebuchadnezzars palace. However, in the case of the newly conquered Judeans, the plan did not work and the Judeans found ways to maintain their own cultural heritage despite the attempted assimilation. The story is told of four young Judean noblemen whose Hebrew names were Daniel, Hananiah, Mishael, and Azariah. They were given new, Babylonian names of Belteshazzar, Shadrach, Meshach, and Abednego, respectively and were brought into Nebuchadnezzars palace. Determined to not eat anything that was not in accord with the dietary rules of Judean religious culture, they requested that they be given a vegetarian diet. The palace official in charge of them was skeptical of their request, knowing that if they began to look less robust and healthy than the young men who were also in training, he would be killed for not taking good care of them. Daniel suggested that they try an experiment. He asked that for ten days, the four of them be fed a vegetarian diet, and at the end of that time, be compared with the other young men to see who looked healthier. So, lets look at the experiment Question: Will eating a vegetarian diet make us unhealthy? Hypothesis: Eating a vegetarian diet is healthy (or as healthy as or more healthy than a

rich-food diet). Prediction: After eating a vegetarian diet for ten days, we will look at least as healthy by

visual examination, if not healthier, than those who consume a diet of rich foods. Testing: For ten days, we will eat a vegetarian diet, while the other young men eat their

normal rich-food diet. They are, thus, the control group, and the four of us are the experimental group. The four of us makes for both a true group and makes sure there is adequate replication in this experiment.

Data: Here, by our modern standards, the experiment is a bit weak. All that is specified

data-wise is a general physical inspection at the end of the ten days to see who, subjectively, looks the most robust. Today, we would expect some concrete, numerical data to be gathered, perhaps weight, blood pressure, pulse, etc., and averages calculated for each group. However, in 587 BCE, sphygmomanometers and stethoscopes hadnt been invented yet, so they did the best they could. Based on the physical inspection at the end of the ten days, the data were that the four Judean young men appeared healthier and better nourished (Dan. 1:15) than those who had consumed the rich-food diet.

Conclusion: Based on the data (the observed differences in appearance), it was

concluded that not only was the vegetarian diet not harmful to their health, but that, in fact, it made them healthier than those in the control group, and thus it was not only safe but advantageous to continue feeding them the vegetarian diet they had requested.

STEPS AND KEY ELEMENTS OF THE SCIENTIFIC METHOD The scientific method is a set of techniques used by the scientific community to investigate natural phenomena by providing an objective framework in which to make scientific inquiry and analyze the data to reach a conclusion about that inquiry. The steps of the scientific method are as listed.

1. Observe the world around you. A good scientist is observant and sees, hears, or in some other way notices whats going on in the world and becomes curious about whats happening. This often includes studying what others have learned. Scientific knowledge is cumulative.

2. Ask a question about what you see. The scientist then raises a question about their observation. The question raised must have a simple, concrete answer that can be obtained by performing an experiment. For example, How many students came to school today? could be answered by counting the students present on campus, but Why did you come to school today? couldnt really be answered by doing an experiment.

3. Propose a hypothesis as an answer. This is a tentative answer to the question: a testable explanation for what was observed. The scientist tries to explain what caused what was observed. There are several important things to remember about the hypothesis:

a. In a cause and effect relationship, what you observe is the effect, and hypotheses are possible causes or tentative explanations for the observation.

b. Hypotheses are based on previous knowledge and facts. Your answer to the question of what caused the observed effect is based on that previous knowledge, either yours or that of others (from a literature review).

c. Multiple hypotheses should be proposed whenever possible. d. Hypotheses should be testable by experimentation and deductive

reasoning. e. Hypotheses can be proven wrong/incorrect, but can never be proven or

confirmed with absolute certainty. It is impossible to test all given conditions, and someone with more knowledge, sometime in the future, may find a condition under which the hypothesis does not hold true.

Next, the scientist uses deductive reasoning to test the hypothesis. Generally, if a particular hypothesis/premise is true and X experiment is done, then one should expect (predict) a certain result. This involves the use of if-then logic. A prediction is the expected results if the hypothesis and other underlying assumptions and principles are true and an experiment is done to test that hypothesis.

4. Design an experiment to see if the predicted results are obtained. If the expected results are obtained, that supports (but does not prove) the hypothesis. The experimental design explains what will be done in the experiment and includes:

a. the persons or samples that will be tested; i. a control group the group that is not being manipulated by the

experiment. ii. experimental group(s) A group of subjects that are exposed to the

variable of the experiment. iii. replication there should be more than one sample/person in each

group. b. the variables that will be manipulated

i. independent variable the one condition that you change in an experiment.

ii. dependent variable the variable that you measure or observe. The dependent variable gets its name because it is the factor that is dependent on the state of the independent variable.

5. Test your hypothesis and come to some conclusions from the results obtained. This is an investigation of whether the real world behaves as predicted by the hypothesis. As part of the testing, you will do the following.

a. Gather data. b. Analyze the data. (This is where your math and graphing skills will come in

handy.) c. Present conclusions that state what you learned from the experiment, any

weaknesses of the experiment (and/or the design), and other questions for future research.

A FEW MORE THOUGHTS A scientific experiment must be a controlled experiment. The scientist must contrast an experimental group with a control group. The two groups are treated EXACTLY alike except for the ONE variable being tested. Sometimes several experimental groups may be used (but only that one thing may vary among the groups). In an experiment quantitative data is gathered from the subjects. For example, its not enough to say, Im going to see how the dog reacts in this situation. Thats too vague, so rather, in that experiment, the scientist might have a list of certain behaviors, and record how often each of the dogs tested exhibits each of those pre-defined behavior patterns. Data for each of the groups are then averaged and compared statistically. Its not enough to say that the average for group X was one thing and the average for group Y was another, so they were different or not. The scientist must also calculate the standard deviation or some other statistical analysis to document that any difference is statistically significant. In most of the experiments we will do in this class, we will not be completing this step. You would need a class in statistics or someone familiar with statistics to help with this. Research is cumulative and progressive. Scientists build on the work of previous researchers, and one important part of any good research is to first do a literature review to find out what previous research has already been done in the field. Science is a process new things are being discovered and old, long-held theories are modified or replaced with better ones as more data/knowledge is accumulated. A theory is a generalization based on many observations and experiments; a well-tested, verified hypothesis that fits existing data and explains how processes or events are thought to occur. It is a basis for predicting future events or discoveries. Theories may be modified as new information is gained. This definition of a theory is in sharp contrast to colloquial usage, where people say something is just a theory, thereby intending to imply a great deal of uncertainty.

Discoveries not as part of an experiment Serendipity On occasion discoveries dont happen within the confines of the scientific method. Sometimes serendipity (Serendib = former name for Ceylon) happens. The Persian fairy-tale The Three Princes of Serendip illustrates the principle known as serendipity. In this story, three princes make discoveries by insight into accidents pertaining to things they were not seeking. Serendipity is not discovery just by accident alone, but includes the idea that the investigators have intuition, or knowledge, which enables them to recognize and take advantage of unexpected events unrelated to their original quest. The discovery of aspartame is a good example of serendipity, but also an example of very bad lab technique. A chemist at Searle Chemical Company had his coffee cup sitting on the bench top in the chemistry lab next to his experiment. Somehow in the process of doing his experiment and drinking coffee all at the same time (not a good idea if you value your life), he stuck his fingers in his experiment, then into his mouth. The serendipity comes in when he realized that this sweet-tasting accident could make his company and him rich.

REFERENCES Most of this document was taken from the webpage The Scientific Method listed below. Other sites were also used. Stein, Carter J. The Scientific Method, http://biology.clc.uc.edu/courses/bio104/sci_meth.htm. Accessed: 12-29-13. What is a variable in science. http://chemistry.about.com/od/sciencefairprojects/a/What-Is-A-Variable-In-Science.htm. Accessed: 12-31-13. APPENDIX E: Introduction to the Scientific Method. http://teacher.nsrl.rochester.edu/phy_labs/appendixe/appendixe.html. Accessed: 10-27-13. Scientific method. http://en.wikipedia.org/wiki/Scientific_method. Accessed: 10-27-13.