HOW TO SET UP, CONDUCT AND REPORT A SCIENTIFIC STUDY
Original Articles
Figure 4a. Graphical display of experimental design( Courtesy of Dr. Uwe Blunck, Berlin).
did etc.) is put in the past tense( e. g. Van Meerbeeck et al reported that self etching adhesives yielded a thinner hybrid layer than etch & rinse adhesives) and only things that are generally accepted should be written in the present tense( eg. saliva is a buffer or chloroform is a solvent). Every statement in an introduction must be backed with a literature quote. At this stage it is recommended to put the literature quotes in parentheses with just the author names and the year. If the same author has published more than one quoted paper in the same year, then the specific article may be identified with letters: a, b, c, etc.). This leads to the question what should be quoted and listed?
• Earlier work in the area
• Methodology used
• Other publications of importance
• ONLY publications actually used in text! Common errors are that the literature search has failed to find relevant papers to the topic. Often secondary literature is quoted instead of the original source( e. g. Roulet described the use
of Silane in composite formulations in his thesis, referring to Pluddemann et al as the inventers of Silane. An author uses Roulet as a reference for Silane). Another error is quoting a paper for a certain fact that was not described in the quoted paper and finally the quote of opinion instead of experimentally based facts is not correct as well. Today more and more publishers use software to detect plagiarism. This reveals yet another common error: that of the simple use of copy paste to insert text fragments from other articles( even your own!) into your own paper without putting the text in“” and quoting the source. Finally not acknowledging work of your competitors and quoting only your own papers is not an error per se, but a fact that sheds a bad light on your person. Once the objective is clear, the author must provide a way to solve the problem. This is described in“ Materials & Methods”. What to do must be described to the smallest detail BEFORE the experimentation begins and once it has been defined it may NOT be changed, because the situation most likely occurs that the results cannot be correlated to the investigated parameters anymore; the change has introduced another variable. This is big trouble. If a standard method is used, it is sufficient to describe it and to refer to its source. Furthermore it is highly advisable to practice it before it is used for the experiment. If this is ignored, bias is introduced, because the inevitable learning curve is included into the results produced. Very often some new equipment or procedures are used to address a research question and the usefulness is not known. Therefore in these situations usually a pilot study should be performed. It should be dealt with identically to the real experiment, but with a substantially smaller sample size( feasibility study). The outcome of the pilot study may lead to modifications of the“ Materials & Methods” of the main study. The report of a pilot study may either be inserted after the“ Introduction” reporting its“ Materials &
Figure 4b. Graphical display of balanced experimental design.
94 Stoma Edu J. 2017; 4( 2): 90-101 http:// www. stomaeduj. com