Guidelines for Graduate Study

Scientific Method

1. Explanation of Scientific Method

1.1. Scientific theory - a generally accepted explanation of a concept or a broad explanation of natural phenomena.

1.2. Scientific law or principle - a description of natural phenomena that does not vary.

1.3. Thales of Miletus, who flourished in the 6th century BC, was the first natural philosopher according to Hellenic tradition. In addition to predicting a solar eclipse and formalizing the study of geometry in his demonstration of bisecting of a circle by its diameter, he tried to explain all observed natural phenomena in terms of the changes of a single substance, water, which can be seen to exist in solid, liquid, and gaseous states. By stating that water was the basic element of all matter, Thales inadvertently contributed critical reasoning the development of natural science when his disciple argued that water, which is intrinsically wet, could not represent those things that are dry.

1.4. Aristotle made sense of observed nature by asking of any object or process: what is the material involved, what is its form and how did it get that form, and, most important of all, what is its purpose? The proper means of investigation was observation, not experimentation.

1.5. Copernicus’s daring to place the sun, not the earth, in the center of the cosmos upset a fundamental worldview.

1.6. Newton’s publication of the Principia marks the culmination of the scientific revolution, where from the phenomena of motions he would investigate the forces of nature, and then from these forces demonstrate other phenomena.

1.7. Karl Popper's widely accepted criterion for a scientific question is that it must not simply pass the experimental tests that may be applied but that it must be formulated in such a way that falsification is in principle possible

1.8. Carl Friedrich Gauss theory of errors was the first attempt to allow one to make a quantitative estimate of the reliability of the result.

2. Steps of the Scientific Method:

2.1. State the problem - a problem can't be solved if it isn't understood.

2.2. Form a hypothesis - this is a possible solution to the problem formed after gathering information about the problem. The term "research" is properly applied here.

2.3. Test the hypothesis - an experiment is an organized set of procedures performed to determine if the hypothesis solves the problem or not. Experiments are done to gather data. It is very important that good observations and records are made during an experiment.

2.4. Draw conclusions - after examining the data from the experiment, conclusions can be drawn. In it's simplest form, the conclusion will be "yes" the hypothesis was correct, or "no" the hypothesis was not correct.

2.5. If the hypothesis is proven to be incorrect, you must find out what was wrong with it. This might lead to the formation of a hypothesis about the hypothesis!

3. Background on experimental design:

3.1. The foundation of any scientific investigation is its experimental design, a logical outline that guides the gathering and evaluation of information. It is the researcher's plan for testing the validity of a hypothesis. Much thought and hard work accompany the development of a hypothesis and experiments that will yield clear results. A scientist's ability to ask key questions and to formulate them into testable hypotheses may largely determine the success or failure of a given research project.

3.2. The very nature of some questions requires estimations or assumptions to be made. Whenever estimations or assumptions are part of the experimental design, they must be clearly stated and justified as part of the experiment. Any estimation is based on some type of data. The data must be shown as well as the calculations that lead to the final estimate. An assumption is based on some fact. Any assumptions that are key to the experimental design must be stated as well as the reason for starting with this assumption.

4. Designing the experiment:

4.1. Proper controls must be incorporated into each experiment. A control group receives the same treatment as the experimental group except that the factor being tested is applied to the experimental group only, not to the control.

4.2. Experiments must be repeated enough times to allow comparisons between experimental and control groups. It is through such repetition that data can be compared statistically and a high degree of accuracy obtained.

4.3. Experiments must be designed to avoid bias. A researcher must strive to prevent personal opinion about a hypothesis from influencing how tests are made and must also be award of the bias that any technique or instrument may introduce in the outcome of an experiment.

5. Performing the experiment:

5.1. Researchers are meticulous note takers. They make detailed notes in a record book that becomes a scientific diary of the research project in process. Data, or results, accumulate as tests outlined in the experimental design are completed.

5.2. Two types of data:

5.2.1. Anecdotal data - relate in words what happens in an experiment, recording chance observations as well as describing mistakes and unexpected events.

5.2.2. Numerical data - consists of measurements determined by a person or instrument.

5.3. Collecting data is a time-consuming, tedious process, and patience is an essential ingredient in science. As results accumulate, the researcher tries to find patterns or relationships in the data.

5.4. Interpreting data by asking critical questions is essential to determining the cause and effect of experimental observations. When the results of repeated tests are consistent and patterns become discernible, the next stage of the process is reporting the results.

6. Reporting experimental results:

6.1. Science is a powerful group activity, providing many opportunities for correcting errors. Researchers formulate their ideas from data analysis, then describe these ideas at seminars and meetings pertaining to their particular fields. It is through presentations like these that the researcher has an opportunity to interact with others in the field and to see how well their work stands up to peer scrutiny. The researcher then decides whether more experiments are needed or whether it is time to publish the results.

6.2. Publishing a scientific paper is the next step in the reporting process. Hundreds of professional societies throughout the world publish journals containing articles that describe original research. Work so published is then permanently available to the scientific community. Monitoring current developments and searching literature for pertinent information are ongoing aspects of any scientist's work. Most scientists subscribe to several journals and use abstracting services to find pertinent reports in their filed.