1, external validity refers to whether (and to what degree) the results of a study can be generalized to a larger population. Unfortunately, all biological systems are profoundly complex, so simple, unambiguous, direct relationships between objects can be difficult to ascertain.The internal validity of a study is judged by the degree to which its outcomes can be attributed to manipulation of independent variables and not to the effects of confounding variables. Therefore, the study protocol must be designed to control (eg, to keep constant) as many extraneous factors as possible so that any potential cause-and-effect relationship between 2 objects can be judged accurately.It is importantto emphasize that confounding variables can never be fully controlled. Furthermore, the influence of these variables may not be fully appreciated by those conducting the research. External validity is primarily determined by how subjects are selected to participate in a study and by the use of randomization procedures that limit potential bias in how subjects are assigned to treatment groups.Content and Writing Style of the Methods Section. Historically, the methods section was writing a research paper methods referred to as the materials and methods to emphasize the 2 distinct areas that must be addressed. Materials referred to what was examined (eg, humans, animals, tissue preparations) and also to the various treatments (eg, drugs, gases) and instruments (eg, ventilators) used in the study.
A confounding or extraneous variable is anything other than the independent variable of interest that may affect the dependent variable. Therefore, a change in a dependent variable may be due wholly or in part to a change in a confounding variable. For example, a change in vena cava pressure can alter intraocular pressure by its effect upon ocular blood drainage.Evaluation of a potential cause-effect relationship between 2 objects writing an essay for a grant is accomplished through the development of the study design. A study design is simply a strategy to control and manipulate variables that provide an answer to the research question regarding potential cause-and-effect relationships. Validity refers to the credibility of experimental results and the degree to which the results can be applied to the general population of interest. Internal validity refers to the credibility of a study and is determined by the degree to which conclusions drawn from an experiment correctly describe what actually transpired during the study.
Once all elements of the writing an essay response methods section are written, subsequent drafts should focus on how to present those elements as clearly and logically as possibly. The description of preparations, measurements, and the protocol should be organized chronologically. For clarity, when a large amount of detail must be presented, information should be presented in sub-sections according to topic. Material in each section should be organized by topic from most to least important.Introduction, the methods section is the most important aspect of a research paper because it provides the information by which the validity of a study is ultimately judged. Therefore, the author must provide a clear and precise description of how an experiment was done, and the rationale for the specific experimental procedures chosen.It must be written with enough information so that: (1) the experiment could be repeated by others to evaluate whether the results are reproducible, and (2) the audience can judge whether the results and conclusions are valid. Basic Research Concepts, the scientific method attempts to discover cause-and effect relationships between objects (ie, physical matter or processes). In the physical sciences objects are regarded as variables, and a variable is anything that can assume different values.Elucidating a cause-and-effect relationship between objects requires that variables are classified as independent, dependent, or confounding. An independent variable is one that, when manipulated, causes a change in another variable. The variable that changes in response to that manipulation is referred to as a dependent variable. For example, intraocular pressure is a dependent variable that responds to manipulations in independent variables such as blood pressure and pupil size.
Summary, the methods section of a research paper provides the information by which a studys validity is erefore, it requires a clear and make my essay longer precise description of how an experiment was done, and the rationale for why specific experimental procedures were chosen. The methods section should describe what was done to answer the research question, describe how it was done, justify the experimental design, and explain how the results were analyzed.Scientific writing is direct and orderly. Therefore, the methods section structure should: describe the materials used in the study, explain how the materials were prepared for the study, describe the research protocol, explain how measurements were made and what calculations were performed, and state which statistical tests were done to analyze.