Research design hypothesis
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. They are important because they not only help guide the development of the protocol and design of study but also play a role in sample size calculations and determining the power of the study. 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. This page on your website:Often, one of the trickiest parts of designing and writing up any research paper is writing the article is a part of the guide:Select from one of the other courses available:Experimental ty and ical tion and psychology e projects for ophy of sance & tics beginners tical bution in er 44 more articles on this 't miss these related articles:5example of a paper 2. Journal entire experiment revolves around the research hypothesis (h1) and the null hypothesis (h0), so making a mistake here could ruin the whole ss to say, it can all be a little intimidating, and many students find this to be the most difficult stage of the scientific fact, it is not as difficult as it looks, and if you have followed the steps of the scientific process and found an area of research and potential research problem, then you may already have a few is just about making sure that you are asking the right questions and wording your hypothesis statements you have nailed down a promising hypothesis, the rest of the process will flow a lot more easily.. The three-step process it can quite difficult to isolate a testable hypothesis after all of the research and study. The best way is to adopt a three-step hypothesis; this will help you to narrow things down, and is the most foolproof guide to how to write a one is to think of a general hypothesis, including everything that you have observed and reviewed during the information gathering stage of any research design. This stage is often called developing the research example of how to write a hypothesis a worker on a fish-farm notices that his trout seem to have more fish lice in the summer, when the water levels are low, and wants to find out why. His research leads him to believe that the amount of oxygen is the reason - fish that are oxygen stressed tend to be more susceptible to disease and proposes a general hypothesis. Is a good general hypothesis, but it gives no guide to how to design the research or experiment.
There is some directionality, but the hypothesis is not really testable, so the final stage is to design an experiment around which research can be designed, i. Is a testable hypothesis - he has established variables, and by measuring the amount of oxygen in the water, eliminating other controlled variables, such as temperature, he can see if there is a correlation against the number of lice on the is an example of how a gradual focusing of research helps to define how to write a hypothesis. Next stage - what to do with the you have your hypothesis, the next stage is to design the experiment, allowing a statistical analysis of data, and allowing you to test your statistical analysis will allow you to reject either the null or the alternative hypothesis. If the alternative is rejected, then you need to go back and refine the initial hypothesis or design a completely new research is part of the scientific process, striving for greater accuracy and developing ever more refined hypotheses.. Are free to copy, share and adapt any text in the article, as long as you give appropriate credit and provide a link/reference to this ch hypothesis - testing theories and hypothesis - the commonly accepted of a research paper - how to create the structure for e of a research paper - how to write a ch paper question - the purpose of the explorable? Take it with you wherever you research council of ibe to our rss blakstad on chacademicwrite paperfor kidsself-helpsitecodelogintop ign upprivacy policy. 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 re wikipedia, the free to: navigation, article's tone or style may not reflect the encyclopedic tone used on wikipedia. Research design is the set of methods and procedures used in collecting and analyzing measures of the variables specified in the research problem research. The design of a study defines the study type (descriptive, correlational, semi-experimental, experimental, review, meta-analytic) and sub-type (e.
Descriptive-longitudinal case study), research problem, hypotheses, independent and dependent variables, experimental design, and, if applicable, data collection methods and a statistical analysis plan. Research design is the framework that has been created to find answers to research questions. Are many ways to classify research designs, but sometimes the distinction is artificial and other times different designs are combined. In some cases, these types coincide with quantitative and qualitative research designs respectively,[2] though this need not be the case. In fixed designs, the design of the study is fixed before the main stage of data collection takes place. Fixed designs are normally theory-driven; otherwise, it is impossible to know in advance which variables need to be controlled and measured. One reason for using a flexible research design can be that the variable of interest is not quantitatively measurable, such as culture. In other cases, theory might not be available before one starts the choice of how to group participants depends on the research hypothesis and on how the participants are sampled. Treatment") and one "control" condition ("no treatment"), but the appropriate method of grouping may depend on factors such as the duration of measurement phase and participant characteristics:Cross-sectional -sequential matory versus exploratory research[edit]. Research tests a priori hypotheses — outcome predictions that are made before the measurement phase begins. The advantage of confirmatory research is that the result is more meaningful, in the sense that it is much harder to claim that a certain result is generalizable beyond the data set. The reason for this is that in confirmatory research, one ideally strives to reduce the probability of falsely reporting a coincidental result as meaningful.
This probability is known as α-level or the probability of a type i atory research on the other hand seeks to generate a posteriori hypotheses by examining a data-set and looking for potential relations between variables. If the researcher does not have any specific hypotheses beforehand, the study is exploratory with respect to the variables in question (although it might be confirmatory for others). The advantage of exploratory research is that it is easier to make new discoveries due to the less stringent methodological restrictions. Here, the researcher does not want to miss a potentially interesting relation and therefore aims to minimize the probability of rejecting a real effect or relation; this probability is sometimes referred to as β and the associated error is of type ii. In other words, if the researcher simply wants to see whether some measured variables could be related, he would want to increase the chances of finding a significant result by lowering the threshold of what is deemed to be mes, a researcher may conduct exploratory research but report it as if it had been confirmatory ('hypothesizing after the results are known', harking—see hypotheses suggested by the data); this is a questionable research practice bordering on problems versus process problems[edit]. Research designs such as repeated measurements and longitudinal study are needed to address process es of fixed designs[edit]. An experimental design, the researcher actively tries to change the situation, circumstances, or experience of participants (manipulation), which may lead to a change in behavior or outcomes for the participants of the study. The researcher randomly assigns participants to different conditions, measures the variables of interest and tries to control for confounding variables. Therefore, experiments are often highly fixed even before the data collection a good experimental design, a few things are of great importance. First of all, it is necessary to think of the best way to operationalize the variables that will be measured, as well as which statistical methods would be most appropriate to answer the research question. Thus, the researcher should consider what the expectations of the study are as well as how to analyse any potential results. Finally, in an experimental design the researcher must think of the practical limitations including the availability of participants as well as how representative the participants are to the target population.
3] additionally, many researchers employ power analysis before they conduct an experiment, in order to determine how large the sample must be to find an effect of a given size with a given design at the desired probability of making a type i or type ii -experimental research designs[edit]. Experimental research designs do not involve a manipulation of the situation, circumstances or experience of the participants. These designs are also called correlation studies, because correlation data are most often used in analysis. Correlational designs are helpful in identifying the relation of one variable to another, and seeing the frequency of co-occurrence in two natural groups (see correlation and dependence). These designs compare two or more groups on one or more variable, such as the effect of gender on grades. A longitudinal design examines variables such as performance exhibited by a group or groups over time. Case studies are for example the descriptions about the patients of freud, who were thoroughly analysed and (1999) states “a case study approach is particularly appropriate for individual researchers because it gives an opportunity for one aspect of a problem to be studied in some depth within a limited time scale”. Theory research is a systematic research process that works to develop "a process, and action or an interaction about a substantive topic". Upper saddle river, nj: prentice e / traffic sign aphy / type ectural lighting nmental impact y community or ape tive suspension ated box ic guitar re interface ing and raphic lens re interface interaction experience interface c / glass /set lighting ical system ated circuit r weapon ve vity ering design ility of -down and ectual l home design quality onic design t design rial design red society of and industries ational forum research an design design award (chicago). Product design philip designers rise product ts and ries: researchhidden categories: wikipedia articles needing style editing from january 2013all articles needing style logged intalkcontributionscreate accountlog pagecontentsfeatured contentcurrent eventsrandom articledonate to wikipediawikipedia out wikipediacommunity portalrecent changescontact links hererelated changesupload filespecial pagespermanent linkpage informationwikidata itemcite this a bookdownload as pdfprintable version. A non-profit l of the academy of marketing sciencedecember 1974, volume 2, issue 1,Pp 249–261 | cite asstrategy in research design and hypothesis testingauthorsauthors and affiliationsb. Melcherarticleabstractthe efficiency of a research design may be measured in terms of the degree to which knowledge is enhanced within given resource constraints.
Thus, two different types of research design, even though they contain the same number of expected observations, may differ considerably in the amount of information provided. We analyze and compare the relative efficiencies of regression and variance analysis models and their implications to research strategy development. Three major considerations are evaluated: (1) short versus long time horizon (interval until effects of a decision are realized), (2) small versus large cost of erroneous rejection of the null hypothesis and (3) gross versus refined stage of development of the research study. Studies in research methodology vi: the central limit effect for a variety of populations and robustness of z, t and f.