The first scenario is one in which the scientist is not trying to measure a response to change, but rather he or she may be trying to understand the similarities and differences between two subjects. For example, Tyson was not observing a change in his "pygmie" in response to an experimental treatment.
Instead, his research was a comparison of the unknown "pygmie" to humans and apes in order to determine the relationship between them.
A second scenario in which comparative studies are common is when the physical scale or timeline of a question may prevent experimentation. For example, in the field of paleoclimatology, researchers have compared cores taken from sediments deposited millions of years ago in the world's oceans to see if the sedimentary composition is similar across all oceans or differs according to geographic location. Because the sediments in these cores were deposited millions of years ago, it would be impossible to obtain these results through the experimental method.
Research designed to look at past events such as sediment cores deposited millions of years ago is referred to as retrospective research. A third common comparative scenario is when the ethical implications of an experimental treatment preclude an experimental design.
Researchers who study the toxicity of environmental pollutants or the spread of disease in humans are precluded from purposefully exposing a group of individuals to the toxin or disease for ethical reasons. In these situations, researchers would set up a comparative study by identifying individuals who have been accidentally exposed to the pollutant or disease and comparing their symptoms to those of a control group of people who were not exposed.
Research designed to look at events from the present into the future, such as a study looking at the development of symptoms in individuals exposed to a pollutant, is referred to as prospective research.
Comparative science was significantly strengthened in the late 19th and early 20th century with the introduction of modern statistical methods. These were used to quantify the association between variables see our Statistics in Science module.
Today, statistical methods are critical for quantifying the nature of relationships examined in many comparative studies.
The outcome of comparative research is often presented in one of the following ways: And numerous studies have contributed to the determination that the risk of developing lung cancer is 30 times greater in smokers than in nonsmokers NCI, Scientists may opt for comparative research where it would be unethical to conduct an experiment. Louis, asked all of the third- and fourth-year medical students at the teaching hospital to observe an autopsy of a man with a disease so rare, he claimed, that most of the students would likely never see another case of it in their careers.
With the medical students gathered around, the physicians conducting the autopsy observed that the patient's lungs were speckled with large dark masses of cells that had caused extensive damage to the lung tissue and had forced the airways to close and collapse. Alton Ochsner, one of the students who observed the autopsy, would write years later that "I did not see another case until , seventeen years later, when in a period of six months, I saw nine patients with cancer of the lung.
The American physician Dr. Isaac Adler was, in fact, the first scientist to propose a link between cigarette smoking and lung cancer in , based on his observation that lung cancer patients often reported that they were smokers. Adler's observations, however, were anecdotal, and provided no scientific evidence toward demonstrating a relationship.
However, the study had a number of problems. First, it relied on the memory of relatives of deceased individuals rather than first-hand observations, and second, no statistical association was made.
Soon after this, the tobacco industry began to sponsor research with the biased goal of repudiating negative health claims against cigarettes see our Scientific Institutions and Societies module for more information on sponsored research. Beginning in the s, several well-controlled comparative studies were initiated.
Their study showed that 1. Both of these comparisons proved to be statistically significant differences. The statisticians who analyzed the data concluded:. Wynder and Graham also suggested that there might be a lag of ten years or more between the period of smoking in an individual and the onset of clinical symptoms of cancer.
This would present a major challenge to researchers since any study that investigated the relationship between smoking and lung cancer in a prospective fashion would have to last many years. In their discussion, Doll and Hill raise an interesting point regarding comparative research methods by saying,. This is not necessarily to state that smoking causes carcinoma of the lung. The association would occur if carcinoma of the lung caused people to smoke or if both attributes were end-effects of a common cause.
They go on to assert that because the habit of smoking was seen to develop before the onset of lung cancer, the argument that lung cancer leads to smoking can be rejected. They therefore conclude, "that smoking is a factor, and an important factor, in the production of carcinoma of the lung.
Despite this substantial evidence , both the tobacco industry and unbiased scientists raised objections, claiming that the retrospective research on smoking was "limited, inconclusive, and controversial. Wilhelm Hueper of the National Cancer Institute, a scientist with a long history of research into occupational causes of cancers, argued that the emphasis on cigarettes as the only cause of lung cancer would compromise research support for other causes of lung cancer.
The research question , ethics , budget and time are all major considerations in any design. This is before looking at the statistics required, and studying the preferred methods for the individual scientific discipline.
Every experimental design must make compromises and generalizations , so the researcher must try to minimize these, whilst remaining realistic. For biology, psychology and social sciences, there can be a huge variety of methods to choose from, and a researcher will have to justify their choice. The first method is the straightforward experiment, involving the standard practice of manipulating quantitative, independent variables to generate statistically analyzable data.
Generally, the system of scientific measurements is interval or ratio based. The researcher is accepting or refuting the null hypothesis. The results generated are analyzable and are used to test hypotheses , with statistics giving a clear and unambiguous picture. This research method is one of the most difficult, requiring rigorous design and a great deal of expense, especially for larger experiments. The other problem, where real life organisms are used, is that taking something out of its natural environment can seriously affect its behavior.
It is also the biggest drain on time and resources, and is often impossible to perform for some fields, because of ethical considerations. The Tuskegee Syphilis Study was a prime example of experimental research that was fixated on results, and failed to take into account moral considerations. In other fields of study, which do not always have the luxury of definable and quantifiable variables - you need to use different research methods.
These should attempt to fit all of the definitions of repeatability or falsifiability , although this is not always feasible. Opinion based research methods generally involve designing an experiment and collecting quantitative data. For this type of research, the measurements are usually arbitrary, following the ordinal or interval type. Questionnaires are an effective way of quantifying data from a sample group, and testing emotions or preferences.
This method is very cheap and easy, where budget is a problem, and gives an element of scale to opinion and emotion. These figures are arbitrary, but at least give a directional method of measuring intensity. By definition, this experiment method must be used where emotions or behaviors are measured, as there is no other way of defining the variables. The biggest advantage of the naturalistic method of research is that researchers view participants in their natural environments.
This leads to greater ecological validity than laboratory observation, proponents say. Proponents of laboratory observation often suggest that due to more control in the laboratory, the results found when using laboratory observation are more meaningful than those obtained with naturalistic observation.
Laboratory observations are usually less time-consuming and cheaper than naturalistic observations. Of course, both naturalistic and laboratory observation are important in regard to the advancement of scientific knowledge.
Case study research involves an in-depth study of an individual or group of indviduals. Case studies often lead to testable hypotheses and allow us to study rare phenomena.
Case studies should not be used to determine cause and effect, and they have limited use for making accurate predictions. There are two serious problems with case studies — expectancy effects and atypical individuals.
Describing atypical individuals may lead to poor generalizations and detract from external validity. In survey method research, participants answer questions administered through interviews or questionnaires. After participants answer the questions, researchers describe the responses given. In order for the survey to be both reliable and valid it is important that the questions are constructed properly.
Questions should be written so they are clear and easy to comprehend. Another consideration when designing questions is whether to include open-ended, closed-ended, partially open-ended, or rating-scale questions for a detailed discussion refer to Jackson,
Comparison as a scientific research method. Comparative research represents one approach in the spectrum of scientific research methods and in some ways is a hybrid of other methods, drawing on aspects of both experimental science (see our Experimentation in Science module) and descriptive research (see our Description in Science module).
The research methods are often confused with research methodology, which implies the scientific analysis of the research methods, so as to find a solution to the problem at hand. Hence, it seems apt to clarify the differences between research method and research methodology at this juncture, have a look.
The methods used in this quantitative research, and this study in particular, are in stark contrast to the staple of qualitative analysis. The subjects were clinically diagnosed PTSD patients, recruited over an month timeline during which 13 of the 17 subjects admitted completed the testing protocols. Pope and Mays COMPARING AND CONSTRASTING RESEARCH METHODOLOGIES 4 () also agree that qualitative research is meant to discover the meanings perceived by the subjects rather than the point of the researcher (p. 6).
Compare and Contrast Qualitative and Quantitative Research Methods Qualitative research methods are complex meaningful analysis characterised by processes and meanings that are not experimentally examined or measured in terms of mathematical measurements (Lincoln, ; Sarantakos, ). Compare and contrast two of the following five research methods in psychology described in your text or on the internet. These research methods include: Case study, Naturalistic observation, Correlation research, Survey research, and Experimental method.