Published online Apr 12, 2022.
https://doi.org/10.3346/jkms.2022.37.e121
A Practical Guide to Writing Quantitative and Qualitative Research Questions and Hypotheses in Scholarly Articles
Abstract
The development of research questions and the subsequent hypotheses are prerequisites to defining the main research purpose and specific objectives of a study. Consequently, these objectives determine the study design and research outcome. The development of research questions is a process based on knowledge of current trends, cutting-edge studies, and technological advances in the research field. Excellent research questions are focused and require a comprehensive literature search and in-depth understanding of the problem being investigated. Initially, research questions may be written as descriptive questions which could be developed into inferential questions. These questions must be specific and concise to provide a clear foundation for developing hypotheses. Hypotheses are more formal predictions about the research outcomes. These specify the possible results that may or may not be expected regarding the relationship between groups. Thus, research questions and hypotheses clarify the main purpose and specific objectives of the study, which in turn dictate the design of the study, its direction, and outcome. Studies developed from good research questions and hypotheses will have trustworthy outcomes with wide-ranging social and health implications.
INTRODUCTION
Scientific research is usually initiated by posing evidenced-based research questions which are then explicitly restated as hypotheses.1, 2 The hypotheses provide directions to guide the study, solutions, explanations, and expected results.3, 4 Both research questions and hypotheses are essentially formulated based on conventional theories and real-world processes, which allow the inception of novel studies and the ethical testing of ideas.5, 6
It is crucial to have knowledge of both quantitative and qualitative research2 as both types of research involve writing research questions and hypotheses.7 However, these crucial elements of research are sometimes overlooked; if not overlooked, then framed without the forethought and meticulous attention it needs. Planning and careful consideration are needed when developing quantitative or qualitative research, particularly when conceptualizing research questions and hypotheses.4
There is a continuing need to support researchers in the creation of innovative research questions and hypotheses, as well as for journal articles that carefully review these elements.1 When research questions and hypotheses are not carefully thought of, unethical studies and poor outcomes usually ensue. Carefully formulated research questions and hypotheses define well-founded objectives, which in turn determine the appropriate design, course, and outcome of the study. This article then aims to discuss in detail the various aspects of crafting research questions and hypotheses, with the goal of guiding researchers as they develop their own. Examples from the authors and peer-reviewed scientific articles in the healthcare field are provided to illustrate key points.
DEFINITIONS AND RELATIONSHIP OF RESEARCH QUESTIONS AND HYPOTHESES
A research question is what a study aims to answer after data analysis and interpretation. The answer is written in length in the discussion section of the paper. Thus, the research question gives a preview of the different parts and variables of the study meant to address the problem posed in the research question.1 An excellent research question clarifies the research writing while facilitating understanding of the research topic, objective, scope, and limitations of the study.5
On the other hand, a research hypothesis is an educated statement of an expected outcome. This statement is based on background research and current knowledge.8, 9 The research hypothesis makes a specific prediction about a new phenomenon10 or a formal statement on the expected relationship between an independent variable and a dependent variable.3, 11 It provides a tentative answer to the research question to be tested or explored.4
Hypotheses employ reasoning to predict a theory-based outcome.10 These can also be developed from theories by focusing on components of theories that have not yet been observed.10 The validity of hypotheses is often based on the testability of the prediction made in a reproducible experiment.8
Conversely, hypotheses can also be rephrased as research questions. Several hypotheses based on existing theories and knowledge may be needed to answer a research question. Developing ethical research questions and hypotheses creates a research design that has logical relationships among variables. These relationships serve as a solid foundation for the conduct of the study.4, 11 Haphazardly constructed research questions can result in poorly formulated hypotheses and improper study designs, leading to unreliable results. Thus, the formulations of relevant research questions and verifiable hypotheses are crucial when beginning research.12
CHARACTERISTICS OF GOOD RESEARCH QUESTIONS AND HYPOTHESES
Excellent research questions are specific and focused. These integrate collective data and observations to confirm or refute the subsequent hypotheses. Well-constructed hypotheses are based on previous reports and verify the research context. These are realistic, in-depth, sufficiently complex, and reproducible. More importantly, these hypotheses can be addressed and tested.13
There are several characteristics of well-developed hypotheses. Good hypotheses are 1) empirically testable7, 10, 11, 13; 2) backed by preliminary evidence9; 3) testable by ethical research7, 9; 4) based on original ideas9; 5) have evidenced-based logical reasoning10; and 6) can be predicted.11 Good hypotheses can infer ethical and positive implications, indicating the presence of a relationship or effect relevant to the research theme.7, 11 These are initially developed from a general theory and branch into specific hypotheses by deductive reasoning. In the absence of a theory to base the hypotheses, inductive reasoning based on specific observations or findings form more general hypotheses.10
TYPES OF RESEARCH QUESTIONS AND HYPOTHESES
Research questions and hypotheses are developed according to the type of research, which can be broadly classified into quantitative and qualitative research. We provide a summary of the types of research questions and hypotheses under quantitative and qualitative research categories in Table 1.
Table 1
Summary of types of quantitative and qualitative research questions and hypotheses
Research questions in quantitative research
In quantitative research, research questions inquire about the relationships among variables being investigated and are usually framed at the start of the study. These are precise and typically linked to the subject population, dependent and independent variables, and research design.1 Research questions may also attempt to describe the behavior of a population in relation to one or more variables, or describe the characteristics of variables to be measured (descriptive research questions).1, 5, 14 These questions may also aim to discover differences between groups within the context of an outcome variable (comparative research questions),1, 5, 14 or elucidate trends and interactions among variables (relationship research questions).1, 5 We provide examples of descriptive, comparative, and relationship research questions in quantitative research in Table 2.
Table 2
Definitions and examples of quantitative research questions
Hypotheses in quantitative research
In quantitative research, hypotheses predict the expected relationships among variables.15 Relationships among variables that can be predicted include 1) between a single dependent variable and a single independent variable (simple hypothesis) or 2) between two or more independent and dependent variables (complex hypothesis).4, 11 Hypotheses may also specify the expected direction to be followed and imply an intellectual commitment to a particular outcome (directional hypothesis)4. On the other hand, hypotheses may not predict the exact direction and are used in the absence of a theory, or when findings contradict previous studies (non-directional hypothesis).4 In addition, hypotheses can 1) define interdependency between variables (associative hypothesis),4 2) propose an effect on the dependent variable from manipulation of the independent variable (causal hypothesis),4 3) state a negative relationship between two variables (null hypothesis),4, 11, 15 4) replace the working hypothesis if rejected (alternative hypothesis),15 explain the relationship of phenomena to possibly generate a theory (working hypothesis),11 5) involve quantifiable variables that can be tested statistically (statistical hypothesis),11 6) or express a relationship whose interlinks can be verified logically (logical hypothesis).11 We provide examples of simple, complex, directional, non-directional, associative, causal, null, alternative, working, statistical, and logical hypotheses in quantitative research, as well as the definition of quantitative hypothesis-testing research in Table 3.
Table 3
Definitions and examples of quantitative research hypotheses
Research questions in qualitative research
Unlike research questions in quantitative research, research questions in qualitative research are usually continuously reviewed and reformulated. The central question and associated subquestions are stated more than the hypotheses.15 The central question broadly explores a complex set of factors surrounding the central phenomenon, aiming to present the varied perspectives of participants.15
There are varied goals for which qualitative research questions are developed. These questions can function in several ways, such as to 1) identify and describe existing conditions (contextual research questions); 2) describe a phenomenon (descriptive research questions); 3) assess the effectiveness of existing methods, protocols, theories, or procedures (evaluation research questions); 4) examine a phenomenon or analyze the reasons or relationships between subjects or phenomena (explanatory research questions); or 5) focus on unknown aspects of a particular topic (exploratory research questions).5 In addition, some qualitative research questions provide new ideas for the development of theories and actions (generative research questions) or advance specific ideologies of a position (ideological research questions).1 Other qualitative research questions may build on a body of existing literature and become working guidelines (ethnographic research questions). Research questions may also be broadly stated without specific reference to the existing literature or a typology of questions (phenomenological research questions), may be directed towards generating a theory of some process (grounded theory questions), or may address a description of the case and the emerging themes (qualitative case study questions).15 We provide examples of contextual, descriptive, evaluation, explanatory, exploratory, generative, ideological, ethnographic, phenomenological, grounded theory, and qualitative case study research questions in qualitative research in Table 4, and the definition of qualitative hypothesis-generating research in Table 5.
Table 4
Definitions and examples of qualitative research questions
Table 5
Definitions of research hypothesis under qualitative research
Qualitative studies usually pose at least one central research question and several subquestions starting with How or What. These research questions use exploratory verbs such as explore or describe. These also focus on one central phenomenon of interest, and may mention the participants and research site.15
Hypotheses in qualitative research
Hypotheses in qualitative research are stated in the form of a clear statement concerning the problem to be investigated. Unlike in quantitative research where hypotheses are usually developed to be tested, qualitative research can lead to both hypothesis-testing and hypothesis-generating outcomes.2 When studies require both quantitative and qualitative research questions, this suggests an integrative process between both research methods wherein a single mixed-methods research question can be developed.1
FRAMEWORKS FOR DEVELOPING RESEARCH QUESTIONS AND HYPOTHESES
Research questions followed by hypotheses should be developed before the start of the study.1, 12, 14 It is crucial to develop feasible research questions on a topic that is interesting to both the researcher and the scientific community. This can be achieved by a meticulous review of previous and current studies to establish a novel topic. Specific areas are subsequently focused on to generate ethical research questions. The relevance of the research questions is evaluated in terms of clarity of the resulting data, specificity of the methodology, objectivity of the outcome, depth of the research, and impact of the study.1, 5 These aspects constitute the FINER criteria (i.e., Feasible, Interesting, Novel, Ethical, and Relevant).1 Clarity and effectiveness are achieved if research questions meet the FINER criteria. In addition to the FINER criteria, Ratan et al. described focus, complexity, novelty, feasibility, and measurability for evaluating the effectiveness of research questions.14
The PICOT and PEO frameworks are also used when developing research questions.1 The following elements are addressed in these frameworks, PICOT: P-population/patients/problem, I-intervention or indicator being studied, C-comparison group, O-outcome of interest, and T-timeframe of the study; PEO: P-population being studied, E-exposure to preexisting conditions, and O-outcome of interest.1 Research questions are also considered good if these meet the “FINERMAPS” framework: Feasible, Interesting, Novel, Ethical, Relevant, Manageable, Appropriate, Potential value/publishable, and Systematic.14
As we indicated earlier, research questions and hypotheses that are not carefully formulated result in unethical studies or poor outcomes. To illustrate this, we provide some examples of ambiguous research question and hypotheses that result in unclear and weak research objectives in quantitative research (Table 6)16 and qualitative research (Table 7)17, and how to transform these ambiguous research question(s) and hypothesis(es) into clear and good statements.
Table 6
Examples of ambiguous research question and hypothesis that result in unclear and weak research objective in quantitative research, how to transform them into clear and good statements, and points to avoid
Table 7
Examples of ambiguous research question and hypothesis that result in unclear and weak research objective in qualitative research, how to transform them into clear and good statements, and points to avoid
CONSTRUCTING RESEARCH QUESTIONS AND HYPOTHESES
To construct effective research questions and hypotheses, it is very important to 1) clarify the background and 2) identify the research problem at the outset of the research, within a specific timeframe.9 Then, 3) review or conduct preliminary research to collect all available knowledge about the possible research questions by studying theories and previous studies.18 Afterwards, 4) construct research questions to investigate the research problem. Identify variables to be accessed from the research questions4 and make operational definitions of constructs from the research problem and questions. Thereafter, 5) construct specific deductive or inductive predictions in the form of hypotheses.4 Finally, 6) state the study aims. This general flow for constructing effective research questions and hypotheses prior to conducting research is shown in Fig. 1.
Fig. 1
General flow for constructing effective research questions and hypotheses prior to conducting research.
Research questions are used more frequently in qualitative research than objectives or hypotheses.3 These questions seek to discover, understand, explore or describe experiences by asking “What” or “How.” The questions are open-ended to elicit a description rather than to relate variables or compare groups. The questions are continually reviewed, reformulated, and changed during the qualitative study.3 Research questions are also used more frequently in survey projects than hypotheses in experiments in quantitative research to compare variables and their relationships.
Hypotheses are constructed based on the variables identified and as an if-then statement, following the template, ‘If a specific action is taken, then a certain outcome is expected.’ At this stage, some ideas regarding expectations from the research to be conducted must be drawn.18 Then, the variables to be manipulated (independent) and influenced (dependent) are defined.4 Thereafter, the hypothesis is stated and refined, and reproducible data tailored to the hypothesis are identified, collected, and analyzed.4 The hypotheses must be testable and specific,18 and should describe the variables and their relationships, the specific group being studied, and the predicted research outcome.18 Hypotheses construction involves a testable proposition to be deduced from theory, and independent and dependent variables to be separated and measured separately.3 Therefore, good hypotheses must be based on good research questions constructed at the start of a study or trial.12
In summary, research questions are constructed after establishing the background of the study. Hypotheses are then developed based on the research questions. Thus, it is crucial to have excellent research questions to generate superior hypotheses. In turn, these would determine the research objectives and the design of the study, and ultimately, the outcome of the research.12 Algorithms for building research questions and hypotheses are shown in Fig. 2 for quantitative research and in Fig. 3 for qualitative research.
EXAMPLES OF RESEARCH QUESTIONS FROM PUBLISHED ARTICLES
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EXAMPLES OF HYPOTHESES IN PUBLISHED ARTICLES
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EXAMPLES OF HYPOTHESIS AS WRITTEN IN PUBLISHED ARTICLES IN RELATION TO OTHER PARTS
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CONCLUSION
Research questions and hypotheses are crucial components to any type of research, whether quantitative or qualitative. These questions should be developed at the very beginning of the study. Excellent research questions lead to superior hypotheses, which, like a compass, set the direction of research, and can often determine the successful conduct of the study. Many research studies have floundered because the development of research questions and subsequent hypotheses was not given the thought and meticulous attention needed. The development of research questions and hypotheses is an iterative process based on extensive knowledge of the literature and insightful grasp of the knowledge gap. Focused, concise, and specific research questions provide a strong foundation for constructing hypotheses which serve as formal predictions about the research outcomes. Research questions and hypotheses are crucial elements of research that should not be overlooked. They should be carefully thought of and constructed when planning research. This avoids unethical studies and poor outcomes by defining well-founded objectives that determine the design, course, and outcome of the study.
Disclosure:The authors have no potential conflicts of interest to disclose.
Author Contributions:
Conceptualization: Barroga E, Matanguihan GJ.
Methodology: Barroga E, Matanguihan GJ.
Writing - original draft: Barroga E, Matanguihan GJ.
Writing - review & editing: Barroga E, Matanguihan GJ.
References
-
Research.com. How to write a research question: Types, steps, and examples. [Updated 2021]. [Accessed January 2, 2022].https://research.com/research/how-
to- write- a- research- question.
-
-
Chigbu UE. Visually hypothesising in scientific paper writing: confirming and refuting qualitative research hypotheses using diagrams. Publications 2019;7(1):22.
-
-
International Institute of Health Sciences. Developing hypothesis and research question. [Updated 2022]. [Accessed January 3, 2022].
-
-
Excelsior College. Research hypotheses. [Updated 2022]. [Accessed February 3, 2022].
-
-
Wordvice. How to write a hypothesis or research question. [Updated 2021]. [Accessed January 4, 2022].
-
-
SCIENCING. Difference between proposition and hypothesis. [Updated 2017]. [Accessed January 5, 2022].
-
-
Misra DP, Agarwal V. Generating working hypothesis for original research studies. Cent Asian J Med Hypotheses Ethics 2020;1(1):14–19.
-
-
PRESSBOOKS. Developing a hypothesis. [Updated 2022]. [Accessed January 6, 2022].
-
-
STUDYANDEXAM. Hypothesis. [Updated 2022]. [Accessed January 6, 2022].
-
-
Farrugia P, Petrisor BA, Farrokhyar F, Bhandari M. Practical tips for surgical research: Research questions, hypotheses and objectives. Can J Surg 2010;53(4):278–281.
-
-
PRESSBOOKS. Scientific inquiry in social work. Inductive and deductive reasoning. [Updated 2022]. [Accessed January 7, 2022].https://scientificinquiryinsocialwork.pressbooks.com/chapter/6-
3- inductive- and- deductive- reasoning/.
-
-
Creswell J. In: Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. 3rd ed. Los Angeles, CA, USA: SAGE; 2009.
-
-
Bhasin H. What is a research hypothesis and how to write it?. [Updated 2020]. [Accessed January 7, 2022].
-
-
Oka M, Horiuchi S, Shimpuku Y, Madeni F, Leshabari S. Effects of a job aid-supported intervention during antenatal care visit in rural Tanzania. Int J Africa Nurs Sci 2019;10:31–37.
-