Primary Research vs Secondary Research for 2025: Definitions, Differences, and Examples

by Imed Bouchrika, Phd

Co-Founder and Chief Data Scientist

Share

Research as a discipline employs a wide variety of methods. While scientists conduct experiments, sociologists often conduct interviews and surveys. Archived texts and artifacts are what historians use. To collect data and test hypotheses, researchers may use primary research or secondary research.

Despite the differences between these two research methods, primary vs secondary research both provide advantages that support specific research objectives. These two forms of research help researchers achieve their goals, and both can prove to be helpful in ensuring that a study is well-researched.

Primary Research vs Secondary Research Table of Contents

1. What is Primary Research?
2. Types of Primary Research
3. Common Pitfalls of Primary Research
4. Ethical Considerations of Primary Research
5. What is Secondary Research?
6. Sources of Secondary Research
7. Important Considerations of Secondary Research
8. Examples of Primary Research vs Secondary Research
9. Practical Applications of Research in Education and Career Advancement
10. What are the best practices for assessing research quality?
11. How to Use Primary and Secondary Research
12. How does technology enhance research effectiveness for 2025?
13. Integrating Primary and Secondary Research: Strategies for Effective Research Design in 2024
14. Is further education essential for optimizing research methodologies?
15. What is the impact of your academic pathway on research career success?
16. How can research expertise lead to high paying career opportunities?
17. Can an accelerated online associates degree fortify your research skillset?
18. Is pursuing fast degrees that pay well a reliable strategy for research career advancement?
19. Can an online master's degree solidify advanced research methodologies?

What is primary research?

The primary research definition refers to research that has involved the collection of original data specific to a particular research project (Gratton & Jones, 2010). When doing primary research, the researcher gathers information first-hand rather than relying on available information in databases and other publications.

This type of research is often carried out with the goal of producing new knowledge, which is why primary research is also referred to as original research. By doing primary research, researchers aim to answer questions that haven’t been answered or even asked before. This degree of originality sets primary research apart from secondary research.

Additionally, original research is crucial for researchers aiming to be published in academic journals, which currently number over 40,000. The degree of originality of the research is a major criterion for publication (Callaham, 2002).

Types of Primary Research

Primary research can be done through various methods, but this type of research is often based on principles of the scientific method (Driscoll, 2010). This means that in the process of doing primary research, researchers develop research questions or hypotheses, collect and analyze measurable, empirical data, and draw evidence-based conclusions. If you want to understand more about conducting an empirical study, you can check out the guide on what is empirical research.

The most common types of primary research are outlined below.

• Surveys This is a data-collection approach where individuals are asked to provide answers to particular research questions, such as about their emotions, beliefs, attitudes, and behavior (Mrug, 2012). This form of questioning tends to be less flexible than interviews due to the fixed nature of the questions. However, surveys are useful for collecting information from large groups of people.
• Interviews Interviews are a convenient way of collecting information from individuals or small groups of people. Researchers can also use interviews to get expert opinions on their fields of study.
• Observation This primary research method involves observing people, occurrences, and other variables important to the research or study. Observation entails measuring and recording quantitative or qualitative data. This research method is useful for gaining knowledge without the biased viewpoint sometimes present in interviews.
• Data analysis Data analysis requires collecting data and organizing them according to criteria developed by the researcher. This primary research method is useful for discovering trends or patterns in data.
• Focus groups Researchers can also gather information through focus groups, which typically comprise up to 12 people. Focus groups participate in a guided discussion of the topic, usually facilitated by the researcher. This qualitative data-gathering method is often used to gain a deeper appreciation of social problems (Nyumba et al., 2018).

Research methods used can also vary, depending on the industry for which the research is needed. For instance, the chart below indicates the emerging research methods used in market research.

Common Pitfalls of Primary Research

There are a few pitfalls that researchers encounter when doing primary research. The most common challenges of primary research, along with recommendations to overcome these potential setbacks, are provided below.

Cost, time, and effort

Due to its nature, primary research tends to require more time, especially compared to secondary research. Primary research methods also require the researcher to be more involved, since they carry out the data collection themselves. Additionally, primary research is more expensive compared to secondary research.

Fortunately, technology helps ease the burden of doing original research today. IOT (Internet of Things) technology, for instance, can be leveraged to gain granular visibility into different sets of data (Sharma, 2019). IOT technology is particularly useful to researchers handling big data. For instance, devices with IoT sensors are constantly collecting data from users and transmitting them to the cloud. Companies can, in turn, use the data gathered by these devices to gain a better understanding of their target market and support marketing campaigns and improve customer service levels. 

Biased methodology or sampling

If a survey or interview is based on biased research methodology, the results will be biased as well. A common type is the so-called ‘response bias, which occurs when participants answer survey or interview questions systematically while in a certain perspective (Wilson & Joye, 2019). For instance, researchers can inadvertently structure questions to encourage participants to respond in a particular way. Questions can also be too confusing or complex for participants to answer accurately. One way to avoid using biased questions is to ensure that these questions are clear, straightforward, and properly constructed.

Researchers can also unintentionally use biased sampling in doing primary research. For instance, a researcher who wants to study social media use among high school students may fail to take into account students who participate in homeschooling. To ensure that a study’s participants are truly representative of a population, sampling should be random and as diverse as possible (Simundic, 2013). This means all subjects have an equal probability of being included in the study.

Too much focus on one or two factors

It is understandable that researchers will not be able to study all factors related to their specific topic. However, these factors should still be considered in the data analysis phase. Putting too much focus on only one or two factors that directly affect your study can prevent you from achieving thorough, well-rounded research.

For instance, if you are studying rates of parking shortage on university campuses, it is not enough to consider only university students who own cars. Factors such as students who commute, faculty members who drive, and the accessibility of other transportation methods must also be considered so you can provide a complete view of the issue.

Finding valid, relevant data

Despite the researcher’s best efforts, participants sometimes will not take the study seriously. For instance, survey participants may provide inaccurate, irrelevant answers to survey questions. Such answers have a significant effect on the conclusion in research, so researchers must take extra caution in examining the results of surveys or interviews. You have the option to not include questionable information gathered from these methods. However, this is not to say that responses that go against your hypothesis should be dismissed.

Ethical Considerations of Primary Research

Aside from its pitfalls, primary research also requires careful consideration of research ethics. This is particularly important for research methods that involve human participants. In the United States, for instance, researchers are often held to the Federal Policy for the Protection of Human Subjects. Also called the Common Rule, these regulations require researchers to obtain and document informed consent and include additional protections for vulnerable research subjects, such as children and pregnant women (Federal Policy for the Protection of Human Subjects, 1991).

Various organizations and industries typically have their own set of research ethics to abide by, but these different ethical research guidelines tend to follow the same principles. The following are some commonly followed ethical considerations for primary research:

• Voluntary participation Researchers must obtain and document express consent or permission from participants before they are involved in any aspect of the primary research.
• Confidentiality and anonymity Participants’ identities must be kept anonymous when results are written or published. This is important because participants may disclose personal information in interviews or surveys.
• Safety and dignity Research participants should not be subjected to harm in any way, and respect for the dignity of research participants should be prioritized.

What is secondary research?

Some may confuse the primary and secondary research definitions. While primary research involves active participation from the researcher themselves, secondary research involves the summary or synthesis of data and literature that has been organized and published by others. When doing secondary research, researchers use and analyze data from primary research sources.

Secondary research is widely used in many fields of study and industries, such as legal research and market research. In the sciences, for instance, one of the most common methods of secondary research is a systematic review. In a systematic review, scientists review existing literature and studies on a certain topic through systematic methods, appraising all available studies to synthesize their findings (Fitchburg State University, 2020).

However, what is the difference between primary and secondary research? The following table highlights the key differences between primary research and secondary research.

Sources of Secondary Research

Researchers have plenty of options to explore when it comes to doing secondary research. The following sources can assist researchers in doing secondary research:

• Academic peer-reviewed journals These often include original research undertaken by authors or researchers themselves.
• Published books and articles Many books reference primary-source materials, along with an analysis from the author.
• Government agencies Many government agencies maintain archives or databases of documents and reports, which contain data that can prove to be useful to researchers.
• Educational institutions Colleges and universities do a significant amount of research and produce data that can be requested by researchers.
• Commercial information sources Information sources such as newspapers, magazines, and TV shows can also prove to be useful sources for secondary research. These sources provide firsthand information and insights into political agendas, market research, and economic developments for instance (Bhat, 2020).

The Internet makes secondary research significantly easier for researchers today. Many government agencies and educational institutions, for instance, make their data available online so researchers can easily download information for their use. There are even web applications for creating world clouds to visualize the frequency of keywords for topics in databases. If you are interested in these applications, you can check out our best word cloud generator list.

Important Considerations of Secondary Research

As with primary research, a researcher also stands to encounter certain issues when doing secondary research. The following are the most important considerations of doing such research method:

Careful evaluation of credibility

Secondary sources must always be evaluated carefully to ensure that it not only fulfills the researcher’s requirements but also meets the criteria of sound scientific practices (Hox & Boejie, 2005). A careful evaluation of collected data and sources ensures that the data can be used as the basis for further research.

For instance, available data may have been collected for a different specific purpose, which may result in deliberate or unintentional bias (Stewart & Kamins, 1993). Such data could prove to be detrimental to a research or study.

Relevance and timeliness of data

Another potential problem inherent in the secondary research process is finding data that is relevant to the researcher’s interest. Secondary data may not be appropriate to the researcher’s purposes, a factor that complicates the process of doing secondary research.

In many cases, secondary data is also old data (Stewart & Kamins, 1993). This is particularly true for census data, which may take up to two years to be collected and made available to the general public. As such, researchers must take into consideration the period during which the data was collected and published.

In this regard, one advantage researchers today have is the growing volume of scientific articles being published each year all over the world. The steady growth of published articles ensures that researchers continue to have access to fresh, original research.

The following chart features countries that achieved the highest growth in publication output of science and engineering articles in 2018:

Examples of Primary Research vs Secondary Research

The following table illustrates the differences between primary and secondary research examples. The first column lists examples of topics, while the second column provides primary research examples of methods and materials that researchers can use for collecting data on these topics. On the other hand, the third column lists examples of studies and articles that can be considered as types of secondary research for the corresponding topics.

Practical Applications of Research in Education and Career Advancement

In the realm of academic and professional pursuits, research methodologies like primary and secondary research serve as indispensable tools. Within the field of education, for example, both approaches can be leveraged to assess learning outcomes, optimize curricula, and adapt teaching methods to diverse student needs. Similarly, career advancement strategies benefit from research-based insights, such as analyzing trends in professional development. 

Moreover, research insights can inform educational policy-making and drive the development of resources that enhance learner engagement. Primary research, such as surveys or interviews with students and educators, can provide first-hand insights into specific challenges. Meanwhile, secondary research helps analyze overarching themes in academic literature or global education trends. Together, they create a robust framework for designing solutions that meet both academic and career-oriented goals.

For individuals pursuing higher education or skill acquisition, it can be beneficial to consider programs tailored to their professional objectives. Online education platforms, for instance, have become integral to modern learning landscapes, blending technology with accessibility to cater to diverse learners. Exploring quality online education programs for personal or professional growth can help researchers remain competitive in an ever-evolving job market. These programs often incorporate both primary and secondary research findings to refine course content, ensuring relevance to current industry standards and learner expectations.

What are the best practices for assessing research quality?

To ensure the reliability and validity of research findings, it is essential to implement stringent quality controls during the research design and analysis phases. This involves clearly defining research objectives, using standardized measurement tools, and ensuring that data collection methods are transparent and replicable. Researchers should employ robust statistical analyses, validate sample sizes for representativeness, and routinely verify that their methodologies minimize bias. Peer review and replication studies further support the credibility of the research process. For those evaluating educational programs or career development courses, exploring a low-cost medical coding and billing online program can also provide insights into how rigorous practices underpin quality program outcomes.

How to Use Primary and Secondary Research

A researcher can choose to use either or both primary or secondary research methods, depending on their objectives. For instance, primary research is ideal if a researcher seeks to make new discoveries or explore new aspects of their field of study. Primary research can also be used to provide authoritative, credible evidence about a topic (Streefkerk, 2018).

Moreover, primary research can be used to produce data that is not only reliable but also specific and relevant to the researcher’s needs. The customized nature of research instruments, such as surveys and interviews also makes primary research ideal for researchers who need a high level of control over data collection methods.

On the other hand, researchers who want to gain more knowledge about their chosen topic will do well to start with secondary research. According to Foley (2019), secondary research serves as a good starting point for any research process. Through secondary research, researchers can determine and understand how their peers have previously approached the topic. Secondary research also allows researchers to collect data in a shorter period and at a lower cost.

Despite their differences, however, primary and secondary research will both prove to be useful in the research process. Foley suggests that both research methods are most effective when used together. Studying existing literature and published materials (secondary research) helps researchers determine the extent of existing knowledge on the topic. If insufficient data is present, researchers have the option to devote time and effort to do primary research.

How does technology enhance research effectiveness for 2025?

Technology plays an increasingly vital role in enhancing the effectiveness of both primary and secondary research, offering tools and platforms that streamline the research process. The integration of modern technology has revolutionized data collection, analysis, and accessibility. Here are ways in which technology impacts research in 2024:

• Advanced Data Collection Tools: Digital surveys, apps, and IoT devices make data collection faster and more accurate in primary research. Researchers can now gather vast amounts of data in real-time, especially with online questionnaires and sensors that collect behavioral or environmental data automatically.
• Data Analysis Software: Tools like AI-driven data analytics platforms help researchers analyze large datasets more efficiently. This capability enhances pattern detection and trend analysis, providing more precise insights for both primary and secondary research.
• Machine Learning Algorithms: In secondary research, machine learning algorithms can sift through massive databases of academic papers and sources to identify relevant studies, ensuring that researchers find the most relevant information quickly.
• Cloud-Based Collaboration: Cloud technology allows researchers to collaborate in real-time from different locations, enabling data sharing and co-analysis, which is particularly useful in multi-disciplinary studies involving both primary and secondary research.
• Visualization Tools: Interactive dashboards and visualization tools help researchers present data more effectively. These tools convert complex datasets into charts, graphs, and infographics, making the findings easier to interpret for stakeholders.

Integrating Primary and Secondary Research: Strategies for Effective Research Design in 2024

1. Why Integrate Primary and Secondary Research?

Combining primary and secondary research provides a comprehensive approach to addressing research questions. Primary research delivers original, tailored data, while secondary research offers a contextual understanding of existing knowledge. Together, these methods:

• Validate findings through triangulation, enhancing reliability.
• Fill data gaps that secondary research alone cannot address.
• Save time and resources by narrowing the scope of primary research through prior insights.

2. Steps for Effective Integration

To successfully blend primary and secondary research, follow these strategic steps:

1. Start with Secondary Research:
2. Define Complementary Objectives:
3. Design an Integrated Framework:
4. Leverage Technology:
5. Synthesize Findings:

3. Real-World Applications

• Market Research: Companies often use secondary market reports to understand trends and primary research (e.g., customer surveys) to gather specific consumer insights.
• Healthcare: Researchers use secondary clinical data to identify gaps and conduct primary patient studies for tailored solutions.
• Social Sciences: Sociologists review historical data and conduct primary focus groups to study cultural phenomena.

4. Benefits of Integration

• Enhanced Accuracy: Using both methods reduces bias and enriches the dataset.
• Resource Efficiency: Secondary research informs and streamlines the scope of primary research, saving time and costs.
• Broader Insights: Integration provides a holistic understanding, combining theoretical and practical perspectives.

5. Challenges and Solutions

While integration is beneficial, researchers may face challenges such as:

• Overlapping Data: Avoid duplication by clearly distinguishing the purpose of each method.
  • Solution: Use a clear framework to delineate primary and secondary data sources.
• Resource Constraints: Balancing time and costs for both methods can be challenging.
  • Solution: Leverage technology and focus on high-priority areas for primary research.

Is further education essential for optimizing research methodologies?

Advanced degree programs can equip researchers with cutting‐edge techniques and contemporary analytical tools designed to refine research methods. Customized curricula often integrate theoretical frameworks with hands‐on applications, enabling professionals to approach data collection, analysis, and interpretation with renewed precision and innovation. Enrollment in accelerated programs, such as the shortest masters programs online, provides immediate access to advanced methodologies and specialized training that are directly applicable to evolving research challenges. This targeted educational investment enhances both strategic insight and technical proficiency, resulting in more robust and credible research outcomes.

What is the impact of your academic pathway on research career success?

Choosing the right academic qualification is crucial for cultivating advanced research skills and meeting industry demands. Prospective researchers must weigh the differences in curriculum focus, program duration, and hands-on training opportunities when evaluating educational programs. For instance, comparing an associate degree vs bachelor degree can highlight distinct advantages in practical experience and theoretical depth. This consideration supports informed decision-making that aligns academic training with targeted research career goals and evolving market requirements.

How can research expertise lead to high paying career opportunities?

In today’s competitive job market, advanced research skills serve as a catalyst for accessing lucrative career pathways across multiple industries. Professionals who master innovative research methodologies and specialize in data-driven analysis are uniquely positioned to influence strategic decision-making and drive organizational success. This expertise can lead to roles in emerging sectors where critical thinking and problem-solving are in high demand. Additionally, targeted career transitions that leverage these competencies often result in substantial financial rewards, as demonstrated in sectors offering high paying jobs for women.

Can an accelerated online associates degree fortify your research skillset?

Accelerated programs are designed to deliver core research competencies in a condensed format, providing a practical foundation that supports advanced methodologies and innovative approaches. This flexible educational pathway combines theoretical principles with real-world applications, enabling immediate application of critical research techniques and data analysis strategies. For professionals eager to bridge the gap between foundational knowledge and specialized research skills, enrolling in an accelerated online associates degree can offer a strategic advantage in rapidly evolving academic and industry landscapes.

Is pursuing fast degrees that pay well a reliable strategy for research career advancement?

Accelerated degree programs are designed to deliver specialized research competencies in a condensed timeframe, enabling professionals to promptly adapt to evolving industry demands. These programs focus on imparting targeted methodologies and practical skills without compromising the foundational principles of sound research practices. Industry insights suggest that aligning career objectives with concise academic training can enhance agility in skill acquisition and facilitate timely career transitions. Candidates are advised to assess program accreditation and curriculum relevance to ensure that the chosen pathway meets both academic rigor and professional benchmarks, as demonstrated by fast degrees that pay well.

Can an online master's degree solidify advanced research methodologies?

Advanced online programs not only advance theoretical understanding but also embed contemporary research techniques into practical learning experiences. These programs emphasize critical analytical skills, incorporating tools for data synthesis and digital trend analysis that are essential for modern research challenges. They also promote best practices in research ethics and methodological rigor, enabling students to integrate diverse data sources into cohesive studies. For additional program options that cater to these advanced needs, consider exploring the easiest online masters degree programs.

Key Insights

• Definition and Purpose
  • Primary Research: Involves the collection of original data specific to a research project, aiming to produce new knowledge.
  • Secondary Research: Involves the summary or synthesis of data and literature that others have published, often used to review existing knowledge.
• Types of Primary Research
  • Surveys: Collect data on emotions, beliefs, attitudes, and behaviors.
  • Interviews: Gather in-depth information from individuals or small groups.
  • Observation: Record data from observations of people, occurrences, and other variables.
  • Data Analysis: Organize collected data to discover trends or patterns.
  • Focus Groups: Conduct guided discussions to gain deeper insights into social problems.
• Common Pitfalls of Primary Research
  • Cost, Time, and Effort: Primary research is often more expensive and time-consuming.
  • Biased Methodology or Sampling: Ensuring unbiased questions and random, diverse sampling is crucial.
  • Narrow Focus: Considering a wide range of relevant factors is essential.
  • Valid Data: Ensuring the accuracy and relevance of data collected from participants.
• Ethical Considerations
  • Voluntary Participation: Obtaining and documenting consent from participants.
  • Confidentiality and Anonymity: Protecting participants' identities and personal information.
  • Safety and Dignity: Ensuring participants are not harmed and their dignity is respected.
• Sources of Secondary Research
  • Academic journals, published books and articles, government agency reports, educational institutions, and commercial information sources.
• Important Considerations of Secondary Research
  • Credibility: Evaluating sources to ensure they meet sound scientific practices.
  • Relevance and Timeliness: Ensuring data is relevant and up-to-date for the research purposes.
• Using Both Methods Together
  • Combining primary and secondary research methods can be effective. Secondary research helps understand existing knowledge, while primary research can fill in gaps where data is insufficient.

FAQ

1. What is the main difference between primary and secondary research?

Primary research involves the collection of original data directly by the researcher, whereas secondary research involves summarizing or synthesizing data that has already been collected and published by others.

2. What are some common methods used in primary research?

Common methods include surveys, interviews, observations, data analysis, and focus groups. These methods help gather specific and original data relevant to the researcher's study.

3. Why can primary research be more costly and time-consuming than secondary research?

Primary research requires the researcher to be directly involved in data collection, which often involves significant time, effort, and financial resources. In contrast, secondary research relies on existing data, which is faster and less costly to obtain.

4. How can researchers avoid bias in primary research?

Researchers can avoid bias by ensuring that survey or interview questions are clear, straightforward, and unbiased. Random and diverse sampling methods should be used to ensure that the study's participants are representative of the population.

5. What are the ethical considerations researchers must keep in mind during primary research?

Researchers must obtain voluntary participation, ensure confidentiality and anonymity of participants, and prioritize the safety and dignity of all participants involved in the research.

6. What sources are commonly used for secondary research?

Common sources include academic peer-reviewed journals, published books and articles, government agency reports, data from educational institutions, and commercial information sources like newspapers and magazines.

7. How can researchers ensure the credibility of secondary research sources?

Researchers should evaluate sources carefully to ensure they meet criteria of sound scientific practices and are relevant and timely for their research purposes.

8. Why is it beneficial to use both primary and secondary research methods together?

Using both methods allows researchers to leverage existing knowledge and literature (secondary research) while also gathering specific, original data (primary research) to fill in gaps and support their study comprehensively.

References:

1. Bhat, A. (2020, April 23). Secondary research- Definition, methods, and examples. QuestionPro. https://www.questionpro.com/blog/secondary-research/
2. Callaham, M. (2002). Journal prestige, publication bias, and other characteristics associated with citation of published studies in peer-reviewed journals. JAMA, 287(21), 2847. https://doi.org/10.1001/jama.287.21.2847
3. Driscoll, D. (2010). Introduction to primary research: Observations, surveys, and interviews. In C. Lowe & P. Zemliansky (Eds.), Writing spaces: Readings on writing, vol. 2 (pp. 153-174). https://writingspaces.org/sites/default/files/writing-spaces-readings-on-writing-vol-2.pdf
4. Federal Policy for the Protection of Human Subjects 1991 (US) https://www.hhs.gov/ohrp/regulations-and-policy/regulations/common-rule/index.html#
5. Foley, B. (2019, May 4). How and when to use primary and secondary research. SurveyGizmo. https://www.surveygizmo.com/resources/blog/research-methods-how-and-when-to-use-primary-and-secondary-research/
6. Gratton, C., & Jones, I. (2010). Research methods for sports studies (2nd ed.). Taylor & Francis. https://repository.stkipgetsempena.ac.id/bitstream/575/1/Research_Methods_for_Sports_Studies.pdf
7. Hox, J. J., & Boeije, H. R. (2005). Data collection, primary vs. secondary. Encyclopedia of Social Measurement, 593-599. https://doi.org/10.1016/b0-12-369398-5/00041-4
8. McCrocklin, S. (2018, October 4). Primary vs. secondary research. GeoPoll. https://www.geopoll.com/blog/primary-vs-secondary-research/
9. Mrug, S. (2012). Survey. In N. J. Salkind (Ed.), Encyclopedia of Research Design (pp. 1473-1476). Thousand Oaks, CA: Sage. https://dx.doi.org/10.4135/9781412961288
10. Nyumba, T., Wilson, K., Derrick, C., & Mukherjee, N. (2018). The use of focus group discussion methodology: Insights from two decades of application in conservation. Methods in Ecology and Evolution, 9 (1), 20-32.  https://doi.org/10.1111/2041-210X.12860
11. Research help: EDUC 9300: Educational research (Sargent & Hirsch). (2020, March 20). Home Research Help at Fitchburg State University. https://fitchburgstate.libguides.com/educ9300
12. Sharma, B. (2019, July 23). IoT The buzzword for market researchers. ReadWrite. https://readwrite.com/2019/07/26/iot-the-buzzword-for-market-researchers/
13. Simundic A. M. (2013). Bias in research. Biochemia medica, 23(1), 1215. https://doi.org/10.11613/bm.2013.003
14. Stewart, D. W., & Kamins, M. A. (1993). Secondary research: Information sources and methods (2nd ed.). SAGE.https://dx.doi.org/10.4135/9781412985802
15. Wilson, J., & Joye, S. (2019). Research Designs and Variables. In Research Methods and Statistics: An Integrated Approach (pp. 40-72). Thousand Oaks, CA: Sage. https://dx.doi.org/10.4135/9781071802717