Research questions hypothesis testing

All clinical trials should have a pre-specified research question, which may be stated in the form of a primary hypothesis (or possibly a few primary hypotheses). An objective outcome measure or measures should also be clearly identified, such as the results of a biochemical test or the score on a validated scale. This allows statistical tests to be applied in order to assess the likelihood that any differences in response between treatment groups resulted from the active treatment and were not due to chance. 

The research question in equivalence trials is structured differently from the research question in superiority trials. The hypothesis testing approach that works so well in superiority trials is of little value in an equivalence trial. As Matthews (2006) commented, Failing to establish that one treatment is superior to the other is not the same as establishing their equivalence. ... 

Formulation of a well-defined research question or study hypothesis that is suitable for testing. 

In this book all research questions are addressed and then answered via the construction of two research hypotheses, commonly called the null hypothesis and the alternate hypothesis. (Although another name for the alternate hypothesis, the research hypothesis, has its own appeal, we employ the commonly used term "alternate hypothesis" in this book.) Both of these hypotheses are key components of the procedure of hypothesis testing. This procedure is a statistical way of doing business. It is described and discussed in detail in Chapter 6, but it is beneficial to introduce the main concept here. 

Statistical hypothesis testing represents a means to formulate and answer the research question in a quantitative manner. The null hypothesis is the hypothesis that is tested. If quantitative data are produced that are not consistent with the null hypothesis, it is rejected. 

Given that the research questions in these trials are different from those used in superiority trials, the formats of the null and alternate hypotheses are also different. The research question associated with an equivalence trial is Does the test drug demonstrate equivalent efficacy compared with the comparator drug The null hypothesis,... 

The research question for a noninferiority trial is stated as Is the test drug not inferior to the control The null hypothesis to be tested in this study is ... 

It is important at the outset to clearly define ones basic goals in the scientific study of living systems. Indeed, these objectives are often difficult to discern from research methodology textbooks. Simply put, this enterprise is primarily concerned with the detection of systematic relationships amidst the morass of variability in biobehavioral responses. This task calls for the partitioning of observed variability into systematic and random components, which in turn will yield patterns of associations such that events can be described, predicted, controlled, and ultimately understood. In the simplest case, a research question or hypothesis is tested by an investigation of the existence, direction, and magnitude of a relationship between an independent or predictor variable (IV) and a DV or criterion variable. 

From this evolution, we come to om research question to what extent have French engineers (not just their official spokespersons) adopted the view of the CNISF/ IFSF Charter In a hypothetico-deductive approach, we propose to observe the relationships between dependent and independent variables corresponding to specific hypotheses that we seek to test or to invalidate (Popper 1973). So, what do we know about the engineering profession in France and what hypothesis can we formulate ... 

Experimental observations are at the heart of chemical research. Many experiments are designed specifically to answer some particular chemical question. Often, the results of these experiments are unexpected and lead to new hypotheses. New hypotheses, in turn, suggest additional experiments. The Chemistry and Life Box describes how the hypothesis of extraterrestrial life can be tested. 

The recent developments and ideas in the field of prebiotic chemistry can be combined with the concepts noted here to produce what we regard as a research outline, rather than a detailed hypothesis, directed toward a coherent theory of the origin of complex self-contained, self-replicating chiral assemblies. In what follows we present one possible scenario that is consistent with our current knowledge of chiral induction and amplification and with the nature of early Earth as well as early life. It is exciting that this fundamental question can be formulated in a way that allows systematic experimental testing as we enter the next century. 

In addition to running control tests, scientists confirm experimental results by repeated testing. The Antarctic researchers, for example, made many food pellets, both experimental and control, so that each test could be repeated many times. Only after obtaining consistent results can a scientist begin to decide whether the hypothesis in question is supported or not. 

The three discoveries helped make Mendeleyevs table more than just a clever way of arranging the elements. His amazingly accurate predictions about the new elements made it clear to other scientists that his table was something more than a fancy list. It was a powerful tool that could be used to hunt down new elements. It was a hypothesis, a scientific statement about the world that researchers could use to test other questions in chemistry. 

The question of iron limitation was brought into sharp scientific focus with a series of public lectures, reports by the US National Research Council, papers, special publications, and popular articles between 1988 and 1991. What was resolved was the need to perform an open ocean enrichment experiment in order to definitively test the hypothesis that iron limits phytoplankton growth and nutrient and carbon dioxide uptake in HNLC regions. Such an experiment posed severe logistical challenges and had never been conducted. 

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