|Understanding and Enjoying Research
IAFC Conference Report: Reading and Interpreting Research
By Len Kravitz, Ph.D.
An important goal of the research scientist is the publication of the results of a completed study. Scientific journals do not allow for literary embellishments and expressions, often seen in other journals, as the purpose is to communicate the scientific findings as clear as possible, in a highly stylized, distinctive fashion. This often makes it difficult for the applied professional to grasp all that the article has to offer. The purpose of this article is to help bridge much of that communication breach in scientific writing.
In almost every research article you read you will see a definite methodology develop that will help you understand the study. Fortunately, most research journals begin each article with an Abstract that summarizes the study for you. In the Introduction the researchers will define their problem or question that was studied, briefly review related research, and perhaps even hypothesize (make a tentative assumption) possible outcomes of their study. Important to the authenticity and replicability of any scientific finding is how it is studied. This is referred to as the Methods and Procedures section in which the researchers will painstakingly explain how they studied their problem: who the subjects were, how and why they were selected, how many subjects were there, how they were tested, what type of equipment was used, what type of research and statistical design was employed, and how they controlled for all extraneous factors that might effect the study results. Of great interest to all readers are the findings. These are presented in a most direct manner in the Results section. This section is invariably the most difficult to understand because it is a straight forward recounting of the statistical results. The Discussion and Conclusions section explains, discusses and concludes the meaning of the study findings and often parallels these findings to similar studies for comparison. Some journals now have a Practical Applications section which synthesizes the applied usefulness to be gained from the study. If not apparently defined in the article, usually the practical application will be addressed in the last couple of paragraphs by the researchers. The challenge to the reader is to evaluate the methodology of the researchers in order to best ascertain the credibility of the study. Fortunately, most primary research journals (a journal where research is first disclosed) have a very strict peer-review process where two or more specialists in the field of study related to the article critically review the article and recommend whether the article should be accepted or rejected for publication. The next sections of this article will delineate the different types of research and define common terminology presented in studies.
Classification of Research
Research can be differentiated into five categories. The following explanations provide a brief overview of each group so that you can determine the type of research you are reading.
Historical research involves understanding, studying, and explaining past events. Its purpose is to arrive at some
conclusions concerning past occurrences that may help to anticipate or explain present or future events. Understanding past research from high-impact aerobics injuries has helped our industry design step and slide programs that offer safer means of achieving similar goals.
Descriptive research often involves collecting information through data review, surveys, interviews, or observation. This type of research best describes the way things are. A review paper of previously reported research is descriptive research. The music and exercise article in this edition of IDEA Today is an example of this type of research. Often new ideas and theories are discovered and presented from this descriptive process.
Correlational research attempts to determine how related two or more variables are. This degree of relation is expressedas a correlation coefficient. For example, a researcher may way to wish to determine the relationship between cardiorespiratory fitness and self-esteem in college females. What is the relationship between college females cardiorespiratory fitness and their level of self-esteem? If the variables are highly related, a correlation coefficient near + 1.00 will be obtained meaning the variables are positively related. If the two variables are not related, a correlation coefficient near .00 will be obtained. If the correlation coefficient is near -1.00, the variables are inversely related.
Causal-comparative research attempts to identify a cause-effect relationship between two or more groups.
Causal-comparative studies involve comparison in contrast to correlation research which looks at relationship. For
instance, a researcher may wish to compare the body composition of persons who have only trained with free weights versus persons who have only trained with exercise machines. In this case the researcher is not manipulating any variables, only investigating the effect of free weights versus exercise machines on body composition. Obviously, since other factors such as diet, training program, aerobic conditioning could effect body composition, casual-comparative research must be reviewed scrupulously to see how these other factors were controlled.
Experimental research is guided by a hypotheses (or several hypothesis) that states an expected relationship between two or more variables. An experiment is conducted to support or disconfirm this experimental hypothesis. For instance, much of this author's research has been involved with the physiological effects of step training with and without handweights. With this type of experimental research, I have randomly selected the group of subjects, decided the exercise program (step training with handweights, step training without handweights, and a control group which remained physically active but did no step training), tried to control all relevant factors (e.g. no other aerobic programs, no change in diet, no additional resistance training, etc.), and then measured the effect of the step training with and without handweights on a number of variables (such as cardiorespiratory fitness, muscular strength, body composition, blood lipids and lipoproteins, etc.). Experimental research, although very demanding of time and resources, often produces the soundest evidence concerning hypothesized cause-effect relationships (Gay, 1987).
Definition of Common Research Terms
Now that we have a grasp of the different types of research and the methodology how research is presented, lets
define some common terms you may see when reading and evaluating research.
The dependent variable is often referred to as the outcome or criterion variable. It is the change or difference in this
variable that the researcher is investigating. In the step training study illustration above, an example of one dependent variable would be cardiorespiratory fitness. How did the subjects aerobic conditioning change over the course of the study?
The independent variable is also referred to as the cause or experimental variable. In the step training study
example, the independent (or manipulated) variable is step training with or without handweights.
Internal validity refers to the condition that observed differences on the dependent variable were a direct result of
manipulation of the independent variable. For instance, if subjects in the step study example were allowed to continue doing aerobic workouts in addition to the study workouts, it would be difficult to assess any improvement in aerobic conditioning due to step training alone. Therefore, how a researcher designs the study is critical to its conclusions, and your evaluation of them.
External validity refers to how generalizable the results of the study are, or how applicable the results can be
applied to groups outside the experimental setting. In the step training example, the female subjects ages ranged
from 18 to 36 yrs. This made it possible for me to generalize my results to females in a fairly wide age range.
Level of Significance:
In the introduction of the study, the researcher proposed (via the hypotheses) a relationship(s) between two or
more variables. The level of significance, or probability level, statistically tells the researcher how confident she/he
is with these results, and whether to reject or support this hypotheses. The level of significance is commonly set at the p < .05 level. This means that if significant, you are 95 percent confident that the results of your study are due to the independent variable and that 5 percent of the time this result could happen by chance. Some studies set the level of significance at p < .01 which means that you have 99 percent confidence in your results and that 1 percent of the time this result could happen by chance.
Reading ResearchA Basis for Professional Development.
Reading research is a valuable skill to develop. Not only will it keep you abreast of the latest scientific findings,
but it will also allow you to be a better fitness educator to your clients and make intelligent decisions as to the
usefulness of various products and programs. Your education and knowledge is an important foundation of who you are as a professional. Your ability to read, synthesize, and apply new and changing scientific knowledge will help define how this foundation is constructed.
Gay, L. R. (1987). Educational research: Competencies for analysis and application (3rd ed.). New York: Merrill.