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Your partner for better health, hypothesis in research: definition, types and importance .

April 21, 2020 Kusum Wagle Epidemiology 0

hypothesis research importance

Table of Contents

What is Hypothesis?

Different Types of Hypothesis:

1. Simple Hypothesis:

2. Complex Hypothesis:

3. Working or Research Hypothesis:

4. Null Hypothesis:

5. Alternative Hypothesis:

6. Logical Hypothesis:

7. Statistical Hypothesis:

Although there are different types of hypothesis, the most commonly and used hypothesis are Null hypothesis and alternate hypothesis . So, what is the difference between null hypothesis and alternate hypothesis? Let’s have a look:

Major Differences Between Null Hypothesis and Alternative Hypothesis:

Importance of hypothesis:.

Characteristics of Good Hypothesis:

References and For More Information:

https://ocw.jhsph.edu/courses/StatisticalReasoning1/PDFs/2009/BiostatisticsLecture4.pdf

https://keydifferences.com/difference-between-type-i-and-type-ii-errors.html

https://www.khanacademy.org/math/ap-statistics/tests-significance-ap/error-probabilities-power/a/consequences-errors-significance

https://stattrek.com/hypothesis-test/hypothesis-testing.aspx

http://davidmlane.com/hyperstat/A2917.html

https://study.com/academy/lesson/what-is-a-hypothesis-definition-lesson-quiz.html

https://keydifferences.com/difference-between-null-and-alternative-hypothesis.html

https://blog.minitab.com/blog/adventures-in-statistics-2/understanding-hypothesis-tests-why-we-need-to-use-hypothesis-tests-in-statistics

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Understanding the importance of a research hypothesis

A research hypothesis is a specification of a testable prediction about what a researcher expects as the outcome of the study. It comprises certain aspects such as the population, variables, and the relationship between the variables. It states the specific role of the position of individual elements through empirical verification. When conducting research, there are certain assumptions that are made by the researcher. According to the available information, the goal is to present the expected outcome after testing them.

A hypothesis should be precise and accurate

A hypothesis is a clear statement of the information that the researcher intends to investigate. It is thus a clear statement that is essential before conducting research.

Aspects identified by the hypothesis in a thesis

Based on this aspect, the features of the hypothesis are listed below:

Figure 2: Features of Hypothesis

1. Conceptual

The statement of the hypothesis is based on a certain concept i.e. it could be either related to the theory or the pre-assumption of the researcher about certain variables i.e. educated guess. This leads to linking the research questions of the study. It helps the collection of data and conducting analysis as per the stated concept.

People who shop at speciality stores tend to spend more on luxury brands as compared to those who shop at a department store.

2. Verbal statement

The research hypothesis represents a verbal statement in declarative form. The hypothesis is often stated in mathematical form. However, it brings in the possibility of representing the idea, assumption, or concept of the researcher in the form of words that could be tested.

The capability of students who are undergoing vocational training programs is not different from the students undergoing regular studies.

3. Empirical reference

By building a tentative relationship among concepts, hypothesis testing provides an empirical verification of a study. It helps validate the assumption of the researcher.

The quality of nursing education affects the quality of nursing practice skills.

4. Tentative relationship

It links the variables as per assumption and builds a tentative relationship. A hypothesis is initially unverified, therefore the relationship between variables is uncertain. Thus a predictable relationship is specified.

Sleep deprivation affects the productivity of an individual.

5. Tool of knowledge advancement

With help of a hypothesis statement, the researcher has the opportunity of verifying the available knowledge and having further enquiry about a concept. Thus, it helps the advancement of knowledge.

The effectiveness of social awareness programs influences the living standards of people.

The hypothesis statement provides the benefit of assessing the available information and making the appropriate prediction about the future. With the possibility of verifiability and identifying falsifiable information, researchers assess their assumptions and determine accurate conclusions.

People who are exposed to a high level of ultraviolet light tend to have a higher incidence of cancer.

7. Not moral

The hypothesis statement is not based on the consideration of moral values or ethics. It is as per the beliefs or assumptions of the researcher. However, testing and prediction are not entirely based on individual moral beliefs. For example, people having sample moral values would take the same strategy for business management. In this case, it is not the desired objective to study the business management strategy.

Neither too specific nor too general

A hypothesis should not be too general or too specific.

‘Actions of an individual would impact the health’ is too general, and ‘running would improve your health’ is too specific. Thus, the hypothesis for the above study is exercise does have an impact on the health of people.

Prediction of consequences

The hypothesis is the statement of the researcher’s assumption. Thus, it helps in predicting the ultimate outcome of the thesis.

Experience leads to better air traffic control management.

Even if the assumption of the researcher is proven false in testing, the result derived from the examination is valuable. With the presence of null and alternative hypotheses, each assessment of the hypothesis yields a valuable conclusion.

Separating irrelevant information from relevant information

 A hypothesis plays a significant role ineffectiveness of a study. It not only navigates the researcher but also prevents the researcher from building an inconclusive study. By guiding as light in the entire thesis, the hypothesis contributes to suggesting and testing the theories along with describing the legal or social phenomenon.

Importance of Hypothesis

Navigate research

A hypothesis helps in identifying the areas that should be focused on for solving the research problem. It helps frame the concepts of study in a meaningful and effective manner. It also helps the researcher arrive at a conclusion for the study based on organized empirical data examination.

Prevents blind research

A hypothesis guides the researcher in the processes that need to be followed throughout the study. It prevents the researcher from collecting massive data and doing blind research which would prove irrelevant.

A platform for investigating activities

By examining conceptual and factual elements related to the problem of a thesis, the hypothesis provides a framework for drawing effective conclusions. It also helps stimulate further studies.

Describes a phenomenon

Each time a hypothesis is tested, more information about the concerned phenomenon is made available. Empirical support via hypothesis testing helps analyse aspects that were unexplored earlier.

Framing accurate research hypothesis statements

For the deduction of accurate and reliable outcomes from the analysis, belong stated things should be noted:

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A hypothesis is used to explain a phenomenon or predict a relationship in communication research. There are four evaluation criteria that a hypothesis must meet. First, it must state an expected relationship between variables. Second, it must be testable and falsifiable; researchers must be able to test whether a hypothesis is truth or false. Third, it should be consistent with the existing body of knowledge. Finally, it should be stated as simply and concisely as possible.

Formulating a hypothesis requires a specific, testable, and predictable statement driven by theoretical guidance and/or prior evidence. A hypothesis can be formulated in various research designs. In experimental settings, researchers compare two or more groups of research participants to investigate the differences of the research outcomes. These ...

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Introduction, sources of hypothesis, characteristics of a good hypothesis, types of hypothesis.

Importance of hypothesis

Ezoic

Hypothesis: definition; characteristics; types; difference & importance

A good research question should guide you to formulate the right hypothesis of your study. But before we go in to details, what is hypothesis and what does it entail? Remember we are defining hypothesis NOT research Hypothesis!

There are diverse definitions that refer to hypothesis. Some of them are as follows;

Definition 1: Hypothesis is official uncertain statement that the researcher frames to portray the expected correlational perspective between two or more variables under investigation or being studied.

Definition 2: Hypothesis is a rational forecast of a specific event happening before the researcher carryout any empirical confirmation or evidence to support it.

Definition 3: Hypothesis in scientific expression. It is a tentative theory or testable statement about the association between two or more variables.

 Therefore, a hypothesis will guide the audience on how or why an event happens or occurs in the natural phenomenon. It achieves this objective by giving a clear explanation using facts on the ground or using some reasonable/logical assumptions although not yet tested for approval.

NB: That, a research question should lead the researcher to hypothetical claim of logical expected outcome of the research study.

Therefore, a hypothesis is a scientific suggestion of the expected research finding of the association between or amongst the study variables and this means the hypothesis should be specific, testable and falsifiable . Therefore, these three key aspects drives us to curiously establish the key characteristic indicators of a good research hypothesis.

How does hypothesis come about? Where does this proposition, supposition, suggestion, premises or theory come from? The following are some of the origins of a hypothesis. These are;

1). Premonition or intuition/personal insight;

This is an original idea or a virgin idea that one comes up with. This implies that it is an idea that has never been in existence before. Although virgin ideas may bring in unique contribution(s) to the body of existing knowledge, it may suffer two major challenges, one; the association that is discovered between the two or more variables as per the hypothesis, may fail to be in existence in other studies. Two; the concept or relationship may lack other similar theories to back it up. But they can be a Centre of interest for further research by scholars. In fact, it can translate into an explanatory theory.

2). Research Findings

From other research findings as per past literature review, one can develop a new hypothesis. Once the hypothesis is proven through empirical tests, then this confirms the previous studies. Hence no re-inventing the wheel by the researcher although it will always appear as if it is a replication of past studies which were conducted in distinctly different conditions. In fact this is the reason as to why most of the institutions of higher learning like Universities incorporate a chapter section of SUMMARY, CONCLUSIONS AND RECOMMENDATIONS mostly in chapter four or five of the project and/or thesis work so as to portray that the current hypothesis is in tandem with the existing research findings and so nothing like re-inventing the wheel.

3). Existing Theory or set of Theories

A Theory is a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained.

A THEORY is the natural, observable, logical, realistic and practical working or relation of two or more characteristics or behavior of a particular subject matter whether of a natural person or otherwise.

Therefore, a theory is a logical relationship between or amongst variables and it is also referred to as conceptual framework. Out of the existing conceptual framework/theory, the researcher out of logical deductions may establish a hypothesis.

4). Social cultural setting

Cultural values and beliefs initiate hypothesis development by social researchers/scientists. They carry out careful observations and generates a number of testable suppositions or premises in the format of hypothesis. So, most of the times, hypotheses may carry the same message but in different contextual setting.

5). Analogy

An analogous situation is a case of similarity, equivalence or likeness which the researcher can replicate to form a hypothesis. To achieve this goal, the researcher needs to test the analogy relationship with a similar characteristic in a different setting or environment. It should be noted that the success of this endeavor is pegged on the researcher’s appreciation of the theory underpinning the analogy and its relevance to the new hypothesis. 

6). Personal Experience

Past experience of the researcher may help in designing the hypothesis. From inference due to continuous interactions and exposure by the researcher can lead to a way of forming a hypothesis. The researcher will establish research questions and look for tentative answers (hypothesis) which will solve the problem at hand in the future. So, the researchers unique life history personal exposure influences his/her perception and conceptualization and hypothesizing of issues.

A good hypothesis has the following characteristics

All these viewpoints of high quality for research purposes are as explained as follows;

2.1 Conceptual Clarity

A good quality hypothesis should maintain clarity in terms of concept definition . The researcher has to ensure that the concept and the study variables used in the study carry the intendent implication to avoid any ambiguity or confusion. This is achieved if the process of operationalization of the study variables is firm and distinct. Operationalization means a way of putting a measurement indicator on a variable to make it observable and measurable . For instance, if we want to measure ones intelligence, we can consider class performance based on marks scored in certain subject.

You see, you cannot touch ones intelligence for all heads look alike but what is inside (i.e. intelligence level) is invisible hence cannot be touched or seen. Therefore, with an examination test we can rank those who have highly scored marks like 80% to 90 or 100% as having high level of intelligence. Otherwise, it will mean medium or low intelligence level. In short the researcher must define how the variable will be manipulated and measured in the study. By clearly detailing the specifics of how the variables were measured and manipulated, other researchers can better understand the results and repeat the study if need be.

2.2 Empirical reference Origin

The hypothesis should be anchored on some empirical literature from past studies. A hypothesis cannot be a stand-alone as far as its origin is concerned. In other words am saying that a researcher cannot wake up one morning and decide to formulate a hypothesis from nowhere. A hypothesis should be from other researched work or findings. The researcher should consider drawing hypothesis from previously published research work based on the theory.

2.3 Objectivity

The hypothesis should observe objectivity in various aspects such as data collection to avoid researcher’s biasedness when choosing the study variables.

2.4 Specificity

 A good hypothesis ought to be specific and not general to the contrary so as to be able to straightaway predict the expected correlation between the study variables. In other words, a hypothesis is a specific, testable prediction about what you expect to happen in a study, so buying a leaf from previously published studies which have been based on the theory to develop a hypothesis is much in order.

To achieve the objective of specificity of the hypothesis, one should ask himself or herself the following questions;

The aforementioned questions ensure that your hypothesis is based on a sure underpinning. They can also be useful in guiding you on revising your hypothesis to eliminate any weaknesses therein.

2.5 Relevance

The hypothesis should be aligned to both the research questions and the research objectives to make sense. On the same breath, it should match the theory to be tested for approval or disapproval.

2.6 Testability

There must be a method to test the validity of the hypothesis to ensure that the researcher does not make moral judgment on the study variables. This ensures that the variables are measurable and verifiable. The quality of testability is key for it portrays in a clear manner how the independent variable can be manipulated and how the dependent variable can be measured in a certain population so as to depict the relational links thereof. You see, a good hypothesis will state the cause-effect implications between the predictor variable and the dependent or criterion variables which are inferentially evaluated to prove their validity.

2.7 Consistency:

A good hypothesis should portray an element of constancy, steadiness or uniformity in every way. Such as being underpinned by a body of theories, research findings and other inter-linked hypothesis. It should further show a connection with existing knowledge.

2.8 Simplicity

A hypothesis should be well understood for it is simple to the users. Therefore, the assumptions and conditions operationalizing the hypothesis should be simple.

2.9 Availability of Technique(s)

A scientific method should be identifiable that can be used to test the proposed hypothesis.

2.10 Purposiveness

The established hypothesis should be for a specific purpose. That is, it should be formulated to answer the research problem and meet the specific research objective .  

2.11 Verifiability

It should be possible to practically verify or validate the hypothesis if it represents good features.

2.12 Profundity of Effect

It means a good quality hypothesis should portray philosophical effect upon a variety of study variables. In other words it should portray a level of understandability of a concept.

2.13 Economical

A hypothesis should show cost-benefit picture. Such that the benefits that accrue to the research at hand is more than the financial or non-financial resources used to facilitate the research exercise.

Hypotheses may be of diverse nature based on the criteria used. The various types of hypotheses are categorized as per several distinct criteria such as;

i). Number of independent and dependent variables in an empirical model Criteria

Under this classification, we have simple and complex hypothesis.

1. Simple Hypothesis

This type of hypothesis is also referred to as composite hypothesis. It is characterized by specification of all the parameters used. This hypothesis forecasts the link between two variables, namely; independent and dependent variables.

2. Complex Hypothesis:

As the name implies, this type of hypothesis portrays the link between more than two independent variables on one side and two or more than two dependent variables. You see, for the simple one as it has been discussed earlier on, it only involves one independent variable and one dependent variable. But for complex case, the independent and dependent variables on both sides of the empirical model are more than one.

ii). Level and nature of outcome assurance Criteria

under this perspective, we have research hypothesis and logical hypothesis

3. Research Hypothesis

It is also referred to as empirical or working hypothesis and it represents a more than sure event occurring hence it is a specific, clear predictor of the event to occur in the future. The hypothesis is based on specific factors of the population.

4. Logical Hypothesis

It is a hypothesis which represents a planned elucidation with inadequate proof. In other words, the suggestion has no actual evidence. The argument is only pegged on reasoning or deduction for there is no actual data.

iii). Basis of either population or sample Criteria

Under this perspective, there is only one class known as statistical hypothesis as explained in number 5.

5. Statistical Hypothesis

It is a hypothesis whose basis suggestion is on the sample tested which represent the population. In this case, the statistical evidence (sample data available) is relied upon to make general conclusion of the population. It is a type of hypothesis, which is used for confirmation purposes and that is why it is referred to as confirmatory data analysis, which carry the population parameter assumption.

iv). Direction of the Association/relationship between the variables Criteria

The possible link between the variables can be witnessed in the type of hypothesis used by a researcher. Under this classification, there are both directional and non-directional hypothesis.

6. Directional Hypothesis

This is a type of hypothesis which is biased to a particular direction of a relationship of the participating variables. Such that the hypothesis supports a more than (>) or less than (<)direction of the relationship of the variables of interest. For instance, the researcher postulates that;

“Those students who actively participate in religious activities in their respective religious affiliations perform better in their religious subjects respectively than those who does not. This is a greater than hypothesis which is assessed using right hand tailed test”.

“Those children who does not feed on starch foods are less active in school extra curriculum activities as compared to those who feed on starch foods. This is a less than (<) hypothesis which is assessed using left hand tailed test”.

7. Non-directional Hypothesis

This is a type of hypothesis which is not biased to any particular direction of a relationship of the participating variables. Such that the hypothesis does not support a more than (>) or less than (<) direction of the relationship of the variables of interest. For instance, the two examples used in the case of directional hypothesis can be postulated as;

Case one: “There is no significant difference in respective religious subject performance between those students who actively participate in religious activities in their respective religious affiliations and those who do not. This is a non-directional hypothesis which is assessed using two tailed tests”.

“Those children who does not feed on starch foods and those who does are statistically the same as far as active participation in school extra curriculum activities is concerned.” This is a non-directional hypothesis which is assessed using two tailed tests”.

v). Causal and Correlational Criteria

Under this perspective, there are two common types of hypotheses, namely; associative and causal hypotheses.

8. Associative Hypothesis

This is a hypothesis which portrays the level of strength or weakness of the association between two variables. It postulates the direction and level of strength two variables only. The direction can be a positive or a negative while the level of association can be weak or strong. This type of hypothesis is measured using Pearson product-moment correlation coefficient approach.

a). There exists a strong positive relationship between the weather changes and the level of mango productivity. Implying that the expected relationship is that when the weather is conducive, more mangoes are produced or increase in a large way.

b). The association between customer price and demand level for night dresses is weak and negative. Implying that the expected relationship is that when the price increase, night dresses demanded decrease slightly.

9. Causal Hypothesis

This is a hypothesis which portrays the cause-effect relationship between or amongst two or more variables. It postulates the significant level of the influence of the variables used in the empirical model.  The cause-effect relationship can either be statistically significant or not statistically significant. This type of hypothesis is measured using inferential statistics such as F-test, R-Squared ( R2 ) or t-statistics.

vi). Theory Development Criteria

Majorly, suppositions can be based on how the researcher infer the relationship based on general or specific theory development. Hence we have the inductive and deductive hypothesis.

10. Inductive Hypothesis

This is a type of hypothesis which is postulated by moving from specific to general argument or conclusion. In other words, this hypothesis advocate for Generalizing from the specific observations to the general conclusion. At the end of it all, the outcome is building of a new theory. Inductive hypothesis works well where there is no theory in existence.

11. Deductive Hypothesis

This is a type of hypothesis which is postulated by moving from to general to specific argument or conclusion. In other words, this hypothesis advocate for Generalizing from the specific observations to the general conclusion. At the end of it all, the outcome is falsification or verification of existing theory. Deductive hypothesis works well where there exists a theory which the researcher is either trying to approve or disapprove.

vii). Statistical Significance Criteria

This criteria focuses on the level of statistical significance of the cause-effect relationship between two or more variables in an empirical model. Under this guideline, we have two commonly used hypotheses, that is Null and Alternative Hypotheses.

12. Null Hypothesis

The hypothesis is expressed in a general way with connotation that there exists no relationship between or amongst some variables. It is symbolically expressed as H 0 .

Now, in a study, a prediction on the event to occur is expressed in a manner that no link exists. There are two ways in which the statement should be expressed.

“ There is no significant relationship between X and Z ”.

This is the most common expression used to imply a null hypothesis by most of the researchers or scholars. Caution is needed here for this expression has a shortcoming for it implies that there is an element of pre-emptying the expectations of the researcher.

You see, if you say there is no significant relationship , it means you already know that there are no reliable results expected at the end of it all. In other words, you know your proposition or supposition is not appropriate. Such a statement can be likened with a scenario like that of your friend telling you that he is wishing to visit the boss in his/her office in a certain locality and at the same time he/she has enough information that he is NOT IN THE OFFICE. So, he puts it this way, “ The boss is not in his office and I am going there to meet him. ” This means your friend is simply wasting his resources to make a visit to an office when he pretty knows that the occupant is absent. This takes us to the second expression of null hypothesis.

To rectify this common expression in research, the researcher needs to express null hypothesis as follows;

“ The relationship between X and Z is not statistically significant. ”

This implies that the researcher has first of all appreciated that there is a relationship that exist between X and Z. Then he/she goes ahead and declares that it is not significant. You see, putting it this way is also away of implying relationship aspect is what is taking you to the field to collect data.

This is the way to set the null hypothesis although sometimes it is dictated by the institution’s or sponsor’s format adopted.

13. Alternative Hypothesis

An alternative hypothesis is the opposite of null hypothesis for it is a statement which portrays some statistical significance between two variables and it is usually expressed as H1 or HA .

In any study, the researcher is after rejection of the null hypothesis to accept the alternative hypothesis. When this happens, implies that the researcher’s proposition or proposal was correct. When testing hypothesis in research, the null and alternative hypothesis are commonly utilized.

So, what is the difference between null and alternative hypothesis? The differences are as portrayed by Table1.1 below

Table 1.1: Difference between Null & Alternative Hypothesis

hypothesis research importance

There are numerous roles that a hypothesis plays in a study. This include and not limited to;

hypothesis research importance

Importance of Hypothesis

Some of the factors responsible for the importance of hypothesis are discussed as under.

To the Point Enquiry

Hypothesis makes a research activity to the point and destination, Research without hypothesis is like a sailor in the sea without compass . So, research is to the point enquiry of problem due to the guidance of hypothesis.

Development of Research Techniques

There are various types of social problems which are complex in nature . For this research is very difficult. We cannot cover it with a single technique but it requires many techniques. These techniques are due to hypothesis provided to a researcher.

Separating Relevant From Irrelevant Observation

A Researcher during study will take the observations and facts which are accordance to the condition and situation. While drop out the irrelevant facts from his study. This separation is due to hypothesis formulation which keeps away relevant observation from irrelevant.

Selecting Required Facts

During study a researcher come across many factors but he confined himself to the selection of required facts through formulation of hypothesis. Hypothesis helps him in selection of relevant facts regarding to the problematic situation .

Direction of Research

Hypothesis acts as a guide master in research. It gives new knowledge and direction to a researcher. It directs a scientist to know about the problematic situation and its causes.

Acts as a Guide

Hypothesis gives new wa ys and direction to a researcher. It acts as a guide and a leader in various organizations or society. It is like the investigator’s eye.

Prevents Blind Research

Hypothesis provides lighting to the darkness of research. It gives difference b/w scientific and unscientific, false and true research. It prevents blind research and give accuracy.

Accuracy & Precision

Hypothesis provides accuracy and precision to a research activity. Accuracy and precision is the feature of scientific investigation which is possible due to hypothesis.

Link between Theory & Investigation

Theory is a source of hypothesis which leads to its formulation . Hypothesis leads to scientific investigation. So, hypothesis acts as a bridge b/w theory and investigation.

Link between Assumption & Observation

During formulation hypothesis is in the stage of assumption. In the field it transformed into hypothesis in working form. This transformation is due to observation in the field. So, it creates a link between assumption & observation.

Provide answer for a Question

A hypothesis highlights the causes of a problematic situation. Further solution is also given by a hypothesis which provides answer to a question.

Save Time, Money & Energy

Hypothesis save time, money and energy of a researcher because it is a guide for him and help him in saving these basic things.

Proper Data Collection

Hypothesis provides the basis of proper Data Collection Relevant and correct information collected by a researcher is the main function of a good formulated hypothesis.

Proper Conclusion

A proper formulated hypothesis may lead to a good reasonable, utilized and proper conclusion. If the hypothesis is better than the conclusions drawn by a researcher would be better for solution of a problem.

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Research questions, hypotheses and objectives

Patricia farrugia.

* Michael G. DeGroote School of Medicine, the

Bradley A. Petrisor

† Division of Orthopaedic Surgery and the

Forough Farrokhyar

‡ Departments of Surgery and

§ Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ont

Mohit Bhandari

There is an increasing familiarity with the principles of evidence-based medicine in the surgical community. 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. 1

Objectives of this article

In 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 objectives.

Research question

Interest 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 Questions then arise out of a perceived knowledge deficit within a subject area or field of study. 2 Indeed, Haynes suggests that it is important to know “where the boundary between current knowledge and ignorance lies.” 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 investigation.

Increasing one’s knowledge about the subject of interest can be accomplished in many ways. Appropriate methods include systematically searching the literature, in-depth interviews and focus groups with patients (and proxies) and interviews with experts in the field. In addition, awareness of current trends and technological advances can assist with the development of research questions. 2 It is imperative to understand what has been studied about a topic to date in order to further the knowledge that has been previously gathered on a topic. Indeed, some granting institutions (e.g., 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 trial.

In-depth knowledge about a subject may generate a number of questions. It then becomes necessary to ask whether these questions can be answered through one study or if more than one study needed. 1 Additional research questions can be developed, but several basic principles should be taken into consideration. 1 All questions, primary and secondary, should be developed at the beginning and planning stages of a study. 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. 1 A sensible strategy is to establish a single primary research question around which to focus the study plan. 3 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. 4

Hulley and colleagues 2 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).

FINER criteria for a good research question

Adapted with permission from Wolters Kluwer Health. 2

Whereas 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). 3 , 5 , 6 Often timing (T) is added to PICO ( Box 2 ) — that is, “Over what time frame will the study take place?” 1 The PICOT approach helps generate a question that aids in constructing the framework of the study and subsequently in protocol development by alluding to the inclusion and exclusion criteria and identifying the groups of patients to be included. Knowing the specific population of interest, intervention (and comparator) and outcome of interest may also help the researcher identify an appropriate outcome measurement tool. 7 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. 1 , 2 A restricted study population (and exclusion criteria) may limit bias and increase the internal validity of the study; however, this approach will limit external validity of the study and, thus, the generalizability of the findings to the practical clinical setting. Conversely, a broadly defined study population and inclusion criteria may be representative of practical clinical practice but may increase bias and reduce the internal validity of the study.

PICOT criteria 1

A 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 answerable.

Research hypothesis

The primary research question should be driven by the hypothesis rather than the data. 1 , 2 That is, the research question and hypothesis should be developed before the start of the study. This sounds intuitive; however, if we take, for example, a database of information, it is potentially possible to perform multiple statistical comparisons of groups within the database to find a statistically significant association. This could then lead one to work backward from the data and develop the “question.” This is counterintuitive to the process because the question is asked specifically to then find the answer, thus collecting data along the way (i.e., in a prospective manner). Multiple statistical testing of associations from data previously collected could potentially lead to spuriously positive findings of association through chance alone. 2 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 study.

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. 3 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 investigative team would first state a research hypothesis. This could be expressed as a single outcome (e.g., computer-assisted acetabular component placement leads to improved functional outcome) or potentially as a complex/composite outcome; that is, more than one outcome (e.g., computer-assisted acetabular component placement leads to both improved radiographic cup placement and improved functional outcome).

However, when formally testing statistical significance, the hypothesis should be stated as a “null” hypothesis. 2 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. At the end of the study, the null hypothesis is then tested statistically. If the findings of the study are not statistically significant (i.e., 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.e., there is a difference in mean functional outcome between the study groups), errors in testing notwithstanding. 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 article.

Another 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. For example, we asked whether there is there an improvement in outcomes with computer-assisted surgery or whether the outcomes worse with computer-assisted surgery. We presented a 2-sided test in the above example because we did not specify the direction of the difference. A 1-sided hypothesis states a specific direction (e.g., there is an improvement in outcomes with computer-assisted surgery). 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. According to this principle, a clinical (or surgical) trial is ethical only if the expert community is uncertain about the relative therapeutic merits of the experimental and control groups being evaluated. 9 It means there must exist an honest and professional disagreement among expert clinicians about the preferred treatment. 9

Designing 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 objective.

Research objective

The 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. 7 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. Objectives can (and often do) state exactly which outcome measures are going to be used within their statements. 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 These concepts will be discussed in other articles in this series.

From the surgeon’s point of view, it is important for the study objectives to be focused on outcomes that are important to patients and clinically relevant. For example, the most methodologically sound randomized controlled trial comparing 2 techniques of distal radial fixation would have little or no clinical impact if the primary objective was to determine the effect of treatment A as compared to treatment B on intraoperative fluoroscopy time. However, if the objective was to determine the effect of treatment A as compared to treatment B on patient functional outcome at 1 year, this would have a much more significant impact on clinical decision-making. Second, more meaningful surgeon–patient discussions could ensue, incorporating patient values and preferences with the results from this study. 6 , 7 It is the precise objective and what the investigator is trying to measure that is of clinical relevance in the practical setting.

The 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. Low-intensity pulsed ultrasound for chronic patellar tendinopathy: a randomized, double-blind, placebo-controlled trial. Rheumatology 2008;47:467–71.

Research question: How does low-intensity pulsed ultrasound (LIPUS) compare with a placebo device in managing the symptoms of skeletally mature patients with patellar tendinopathy?

Research hypothesis: Pain levels are reduced in patients who receive daily active-LIPUS (treatment) for 12 weeks compared with individuals who receive inactive-LIPUS (placebo).

Objective: To investigate the clinical efficacy of LIPUS in the management of patellar tendinopathy symptoms.

The 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. Useful tips for surgical researchers are provided in Box 3 . 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 efforts.

Tips for developing research questions, hypotheses and objectives for research studies

FINER = feasible, interesting, novel, ethical, relevant; PICOT = population (patients), intervention (for intervention studies only), comparison group, outcome of interest, time.

Competing interests: No funding was received in preparation of this paper. Dr. Bhandari was funded, in part, by a Canada Research Chair, McMaster University.

Forming a Good Hypothesis for Scientific Research

Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology.

hypothesis research importance

Verywell / Alex Dos Diaz

Formulating a Hypothesis

Falsifiability, operational definitions, types of hypotheses, examples of hypotheses.

A hypothesis is a tentative statement about the relationship between two or more  variables. It is a specific, testable prediction about what you expect to happen in a study.

For example, a study designed to look at the relationship between sleep deprivation and test performance might have a hypothesis that states, "This study is designed to assess the hypothesis that sleep-deprived people will perform worse on a test than individuals who are not sleep-deprived."

This article explores how a hypothesis is used in psychology research, how to write a good hypothesis, and the different types of hypotheses you might use.

The Hypothesis in the Scientific Method

In the scientific method, whether it involves research in psychology, biology, or some other area, a hypothesis represents what the researchers think will happen in an experiment.   The scientific method involves the following steps:

The hypothesis is a prediction, but it involves more than a guess. Most of the time, the hypothesis begins with a question which is then explored through background research. It is only at this point that researchers begin to develop a testable hypothesis. Unless you are creating an exploratory study, your hypothesis should always explain what you  expect  to happen.

In a study exploring the effects of a particular drug, the hypothesis might be that researchers expect the drug to have some type of effect on the symptoms of a specific illness. In psychology, the hypothesis might focus on how a certain aspect of the environment might influence a particular behavior.

Remember, a hypothesis does not have to be correct.   While the hypothesis predicts what the researchers expect to see, the goal of the research is to determine whether this guess is right or wrong. When conducting an experiment, researchers might explore a number of factors to determine which ones might contribute to the ultimate outcome.

In many cases, researchers may find that the results of an experiment  do not  support the original hypothesis. When writing up these results, the researchers might suggest other options that should be explored in future studies.

In many cases, researchers might draw a hypothesis from a specific theory or build on previous research. For example, prior research has shown that stress can impact the immune system. So a researcher might hypothesize: "People with high-stress levels will be more likely to contract a common cold after being exposed to the virus than people who have low-stress levels."

In other instances, researchers might look at commonly held beliefs or folk wisdom. "Birds of a feather flock together" is one example of folk wisdom that a psychologist might try to investigate. The researcher might pose a specific hypothesis that "People tend to select romantic partners who are similar to them in interests and educational level."

Elements of a Good Hypothesis

So how do you write a good hypothesis? When trying to come up with a hypothesis for your research or experiments, ask yourself the following questions:

Before you come up with a specific hypothesis, spend some time doing background research. Once you have completed a literature review, start thinking about potential questions you still have. Pay attention to the discussion section in the  journal articles you read . Many authors will suggest questions that still need to be explored.

To form a hypothesis, you should take these steps:

In the scientific method ,  falsifiability is an important part of any valid hypothesis.   In order to test a claim scientifically, it must be possible that the claim could be proven false.

Students sometimes confuse the idea of falsifiability with the idea that it means that something is false, which is not the case. What falsifiability means is that  if  something was false, then it is possible to demonstrate that it is false.

One of the hallmarks of pseudoscience is that it makes claims that cannot be refuted or proven false.

A variable is a factor or element that can be changed and manipulated in ways that are observable and measurable. However, the researcher must also define how the variable will be manipulated and measured in the study.

For example, a researcher might operationally define the variable " test anxiety " as the results of a self-report measure of anxiety experienced during an exam. A "study habits" variable might be defined by the amount of studying that actually occurs as measured by time.

These precise descriptions are important because many things can be measured in a number of different ways. One of the basic principles of any type of scientific research is that the results must be replicable.   By clearly detailing the specifics of how the variables were measured and manipulated, other researchers can better understand the results and repeat the study if needed.

Some variables are more difficult than others to define. How would you operationally define a variable such as aggression ? For obvious ethical reasons, researchers cannot create a situation in which a person behaves aggressively toward others.

In order to measure this variable, the researcher must devise a measurement that assesses aggressive behavior without harming other people. In this situation, the researcher might utilize a simulated task to measure aggressiveness.

Hypothesis Checklist

The hypothesis you use will depend on what you are investigating and hoping to find. Some of the main types of hypotheses that you might use include:

A hypothesis often follows a basic format of "If {this happens} then {this will happen}." One way to structure your hypothesis is to describe what will happen to the  dependent variable  if you change the  independent variable .

The basic format might be: "If {these changes are made to a certain independent variable}, then we will observe {a change in a specific dependent variable}."

A few examples of simple hypotheses:

Examples of a complex hypothesis include:

Examples of a null hypothesis include:

Examples of an alternative hypothesis:

Collecting Data on Your Hypothesis

Once a researcher has formed a testable hypothesis, the next step is to select a research design and start collecting data. The research method depends largely on exactly what they are studying. There are two basic types of research methods: descriptive research and experimental research.

Descriptive Research Methods

Descriptive research such as  case studies ,  naturalistic observations , and surveys are often used when it would be impossible or difficult to  conduct an experiment . These methods are best used to describe different aspects of a behavior or psychological phenomenon.

Once a researcher has collected data using descriptive methods, a correlational study can then be used to look at how the variables are related. This type of research method might be used to investigate a hypothesis that is difficult to test experimentally.

Experimental Research Methods

Experimental methods  are used to demonstrate causal relationships between variables. In an experiment, the researcher systematically manipulates a variable of interest (known as the independent variable) and measures the effect on another variable (known as the dependent variable).

Unlike correlational studies, which can only be used to determine if there is a relationship between two variables, experimental methods can be used to determine the actual nature of the relationship—whether changes in one variable actually  cause  another to change.

A Word From Verywell

The hypothesis is a critical part of any scientific exploration. It represents what researchers expect to find in a study or experiment. In situations where the hypothesis is unsupported by the research, the research still has value. Such research helps us better understand how different aspects of the natural world relate to one another. It also helps us develop new hypotheses that can then be tested in the future.

Castillo M. The scientific method: a need for something better? . AJNR Am J Neuroradiol. 2013;34(9):1669-71. doi:10.3174/ajnr.A3401

Nevid J. Psychology: Concepts and Applications. Wadworth, 2013.

By Kendra Cherry Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology.

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COMMENTS

  1. Hypothesis in Research: Definition, Types And Importance

    Importance of Hypothesis: · It ensures the entire research methodologies are scientific and valid. · It helps to assume the probability of

  2. Understanding the importance of a research hypothesis

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  3. (PDF) Significance of Hypothesis in Research

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  4. The SAGE Encyclopedia of Communication Research Methods

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  5. Hypothesis: definition; characteristics; types; difference & importance

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  7. Research questions, hypotheses and objectives

    Another 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

  8. What is the importance of hypotheses in research?

    Hypothesis acts as a guide master in research. It gives new knowledge and direction to a researcher. It helps to provide link to the underlying theory and

  9. Generating A Research Hypothesis

    A hypothesis is important because it guides the research. An investigator may refer to the hypothesis to direct his or her thought process toward the

  10. Forming a Good Hypothesis for Scientific Research

    In the scientific method, whether it involves research in psychology, biology, or some other area, a hypothesis represents what the researchers