Research and hypothesis
There is no formal hypothesis, and perhaps the purpose of the study is e some area more thoroughly in order to develop some specific hypothesis tion that can be tested in future research. A single study may have one or ly, whenever i talk about an hypothesis, i am really thinking two hypotheses. The way we would formally set up the hypothesis to formulate two hypothesis statements, one that describes your prediction and one bes all the other possible outcomes with respect to the hypothesized prediction is that variable a and variable b will be related (you don't care 's a positive or negative relationship). Usually, we call the you support (your prediction) the alternative hypothesis, and we hypothesis that describes the remaining possible outcomes the esis. Sometimes we use a notation like ha or h1 to alternative hypothesis or your prediction, and ho or h0 ent the null case. In this case,You are essentially trying to find support for the null hypothesis and you are opposed your prediction specifies a direction, and the null therefore is the no tion and the prediction of the opposite direction, we call this a esis.
Your two hypotheses might be null hypothesis for this study is:Ho: as a result of the xyz company employee training program, there be no significant difference in employee absenteeism or there will be a is tested against the alternative hypothesis:Ha: as a result of the xyz company employee training program, there will be. The alternative hypothesis -- your prediction that m will decrease absenteeism -- is shown there. You believe (based on theory and the previous research) that the have an effect, but you are not confident enough to hypothesize a direction and drug will reduce depression (after all, you've seen more than enough promising ents come along that eventually were shown to have severe side effects that ed symptoms). In this case, you might state the two hypotheses like this:The null hypothesis for this study is:Ho: as a result of 300mg. Day of the abc drug, there will be no ence in is tested against the alternative hypothesis:Ha: as a result of 300mg. To the tails of the distribution for your outcome important thing to remember about stating hypotheses is that you formulate tion (directional or not), and then you formulate a second hypothesis that ly exclusive of the first and incorporates all possible alternative outcomes case.
If your original prediction was ted in the data, then you will accept the null hypothesis and reject ative. The logic of hypothesis testing is based on these two basic principles:The formulation of two mutually exclusive hypothesis statements that, together, possible testing of these so that one is necessarily accepted and the other , i know it's a convoluted, awkward and formalistic way to ask research it encompasses a long tradition in statistics called the , and sometimes we just have to do things because they're traditions. If all of this hypothesis testing was easy enough so anybody could understand it,How do you think statisticians would stay employed? Trochim, all rights se a printed copy of the research methods revised: 10/20/ble of contentsnavigatingfoundationslanguage of researchfive big wordstypes of questionstime in researchtypes of relationshipsvariableshypothesestypes of dataunit of analysistwo research fallaciesphilosophy of researchethics in researchconceptualizingevaluation researchsamplingmeasurementdesignanalysiswrite-upappendicessearch. Trochim, all rights se a printed copy of the research methods revised: 10/20/ble of contentsnavigatingfoundationslanguage of researchfive big wordstypes of questionstime in researchtypes of relationshipsvariableshypothesestypes of dataunit of analysistwo research fallaciesphilosophy of researchethics in researchconceptualizingevaluation re ncbi web site requires javascript to tionresourceshow toabout ncbi accesskeysmy ncbisign in to ncbisign l listcan j surgv. As surgeons become more aware of the hierarchy of evidence, grades of recommendations and the principles of critical appraisal, they develop an increasing familiarity with research design.
Surgeons and clinicians are looking more and more to the literature and clinical trials to guide their practice; as such, it is becoming a responsibility of the clinical research community to attempt to answer questions that are not only well thought out but also clinically relevant. The development of the research question, including a supportive hypothesis and objectives, is a necessary key step in producing clinically relevant results to be used in evidence-based practice. A well-defined and specific research question is more likely to help guide us in making decisions about study design and population and subsequently what data will be collected and analyzed. Of this articlein this article, we discuss important considerations in the development of a research question and hypothesis and in defining objectives for research. By the end of this article, the reader will be able to appreciate the significance of constructing a good research question and developing hypotheses and research objectives for the successful design of a research study. The following article is divided into 3 sections: research question, research hypothesis and research ch questioninterest in a particular topic usually begins the research process, but it is the familiarity with the subject that helps define an appropriate research question for a study.
1 the challenge in developing an appropriate research question is in determining which clinical uncertainties could or should be studied and also rationalizing the need for their sing one’s knowledge about the subject of interest can be accomplished in many ways. In addition, awareness of current trends and technological advances can assist with the development of research questions. Canadian institute for health research) encourage applicants to conduct a systematic review of the available evidence if a recent review does not already exist and preferably a pilot or feasibility study before applying for a grant for a full -depth knowledge about a subject may generate a number of questions. Additional research questions can be developed, but several basic principles should be taken into consideration. Any additional questions should never compromise the primary question because it is the primary research question that forms the basis of the hypothesis and study objectives. It must be kept in mind that within the scope of one study, the presence of a number of research questions will affect and potentially increase the complexity of both the study design and subsequent statistical analyses, not to mention the actual feasibility of answering every question.
A sensible strategy is to establish a single primary research question around which to focus the study plan. In a study, the primary research question should be clearly stated at the end of the introduction of the grant proposal, and it usually specifies the population to be studied, the intervention to be implemented and other circumstantial factors. And colleagues2 have suggested the use of the finer criteria in the development of a good research question (box 1). The finer criteria highlight useful points that may increase the chances of developing a successful research project. A good research question should specify the population of interest, be of interest to the scientific community and potentially to the public, have clinical relevance and further current knowledge in the field (and of course be compliant with the standards of ethical boards and national research standards). 1finer criteria for a good research questionffeasibleadequate number of subjectsadequate technical expertiseaffordable in time and moneymanageable in scopeiinterestinggetting the answer intrigues investigator, peers and communitynnovelconfirms, refutes or extends previous findingseethicalamenable to a study that institutional review board will approverrelevantto scientific knowledgeto clinical and health policyto future researchview it in a separate windowadapted with permission from wolters kluwer health.
The finer criteria outline the important aspects of the question in general, a useful format to use in the development of a specific research question is the pico format — consider the population (p) of interest, the intervention (i) being studied, the comparison (c) group (or to what is the intervention being compared) and the outcome of interest (o). Knowing the specific population of interest, intervention (and comparator) and outcome of interest may also help the researcher identify an appropriate outcome measurement tool. The more defined the population of interest, and thus the more stringent the inclusion and exclusion criteria, the greater the effect on the interpretation and subsequent applicability and generalizability of the research findings. Is the appropriate follow-up time to assess outcomeview it in a separate windowa poorly devised research question may affect the choice of study design, potentially lead to futile situations and, thus, hamper the chance of determining anything of clinical significance, which will then affect the potential for publication. Without devoting appropriate resources to developing the research question, the quality of the study and subsequent results may be compromised. During the initial stages of any research study, it is therefore imperative to formulate a research question that is both clinically relevant and ch hypothesisthe primary research question should be driven by the hypothesis rather than the data.
2 that is, the research question and hypothesis should be developed before the start of the study. Therefore, a good hypothesis must be based on a good research question at the start of a trial and, indeed, drive data collection for the research or clinical hypothesis is developed from the research question and then the main elements of the study — sampling strategy, intervention (if applicable), comparison and outcome variables — are summarized in a form that establishes the basis for testing, statistical and ultimately clinical significance. For example, in a research study comparing computer-assisted acetabular component insertion versus freehand acetabular component placement in patients in need of total hip arthroplasty, the experimental group would be computer-assisted insertion and the control/conventional group would be free-hand placement. The purpose of hypothesis testing is to make an inference about the population of interest on the basis of a random sample taken from that population. The null hypothesis for the preceding research hypothesis then would be that there is no difference in mean functional outcome between the computer-assisted insertion and free-hand placement techniques. After forming the null hypothesis, the researchers would form an alternate hypothesis stating the nature of the difference, if it should appear.
The alternate hypothesis would be that there is a difference in mean functional outcome between these techniques. There is no difference in functional outcome between the groups in a statistical sense), we cannot reject the null hypothesis, whereas if the findings were significant, we can reject the null hypothesis and accept the alternate hypothesis (i. In other words, hypothesis testing confirms or refutes the statement that the observed findings did not occur by chance alone but rather occurred because there was a true difference in outcomes between these surgical procedures. The concept of statistical hypothesis testing is complex, and the details are beyond the scope of this r important concept inherent in hypothesis testing is whether the hypotheses will be 1-sided or 2-sided. A 2-sided hypothesis states that there is a difference between the experimental group and the control group, but it does not specify in advance the expected direction of the difference. A 2-sided hypothesis should be used unless there is a good justification for using a 1-sided hypothesis.
As bland and atlman 8 stated, “one-sided hypothesis testing should never be used as a device to make a conventionally nonsignificant difference significant. The research hypothesis should be stated at the beginning of the study to guide the objectives for research. Whereas the investigators may state the hypothesis as being 1-sided (there is an improvement with treatment), the study and investigators must adhere to the concept of clinical equipoise. A research hypothesis is supported by a good research question and will influence the type of research design for the study. Acting on the principles of appropriate hypothesis development, the study can then confidently proceed to the development of the research ch objectivethe primary objective should be coupled with the hypothesis of the study. Study objectives define the specific aims of the study and should be clearly stated in the introduction of the research protocol.
From our previous example and using the investigative hypothesis that there is a difference in functional outcomes between computer-assisted acetabular component placement and free-hand placement, the primary objective can be stated as follows: this study will compare the functional outcomes of computer-assisted acetabular component insertion versus free-hand placement in patients undergoing total hip arthroplasty. Note that the study objective is an active statement about how the study is going to answer the specific research question. 7 it is the precise objective and what the investigator is trying to measure that is of clinical relevance in the practical following is an example from the literature about the relation between the research question, hypothesis and study objectives:study: warden sj, metcalf br, kiss zs, et al. Hypothesis: pain levels are reduced in patients who receive daily active-lipus (treatment) for 12 weeks compared with individuals who receive inactive-lipus (placebo). To investigate the clinical efficacy of lipus in the management of patellar tendinopathy sionthe development of the research question is the most important aspect of a research project. A research project can fail if the objectives and hypothesis are poorly focused and underdeveloped.
Designing and developing an appropriate and relevant research question, hypothesis and objectives can be a difficult task. The critical appraisal of the research question used in a study is vital to the application of the findings to clinical practice. Focusing resources, time and dedication to these 3 very important tasks will help to guide a successful research project, influence interpretation of the results and affect future publication 3tips for developing research questions, hypotheses and objectives for research studiesperform a systematic literature review (if one has not been done) to increase knowledge and familiarity with the topic and to assist with research about current trends and technological advances on the careful input from experts, mentors, colleagues and collaborators to refine your research question as this will aid in developing the research question and guide the research the finer criteria in the development of the research that the research question follows picot p a research hypothesis from the research p clear and well-defined primary and secondary (if needed) that the research question and objectives are answerable, feasible and clinically = feasible, interesting, novel, ethical, relevant; picot = population (patients), intervention (for intervention studies only), comparison group, outcome of interest, tescompeting interests: no funding was received in preparation of this paper. Pubmed]articles from canadian journal of surgery are provided here courtesy of canadian medical s:article | pubreader | epub (beta) | pdf (147k) | authors and ations > journals > exploratory research and hypothesis in medicine > journal ction for atory research and hypothesis in . Christopher ne therapeutics, sity medical center of princeton/rutgers ch and hypothesis in medicine (erhm) al exploratory research articles and state-of-the-art reviews that novel findings and the most recent scientific advances that support eses in medicine. The exploratory hed in erhm does not necessarily need to be comprehensive and conclusive,But the study design must be solid, the methodologies must be reliable, s must be true, and the hypothesis must be rational and justifiable es and encourages article submission of original exploratory research as novel and timely state-of-the-art full reviews, mini-reviews, and es from leading scientists and scholars around the world.
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