Best Practice

Constant Comparative Method in Qualitative Research

In constant comparison, the qualitative analysis process consists of looking at your existing data and conducting qualitative coding to generate theories from your research. In this article, we'll look at the constant comparative method and the steps necessary to conduct constant comparison.
Lauren Stewart
Qualitative Data Analysis Expert & ATLAS.ti Professional
  1. Introduction
  2. What is constant comparison in qualitative research?
  3. What is an example of a comparative analysis?
  4. Step-by-step guide to using the constant comparative method
  5. Benefits of using the constant comparative method


Constant comparison is an essential qualitative research method that originally comes from grounded theory analysis. Under the constant comparative method, the goal of the qualitative data collection process and data analysis is to facilitate organization of information to generate a coherent theory. In this article, we'll examine constant comparative analysis and its place in qualitative research methods.

The constant comparative method is a common tool used in qualitative analysis.

What is constant comparison in qualitative research?

Constant comparison in qualitative research is a systematic procedure used for collecting data and analyzing that raw data throughout the research process. This method is closely associated with grounded theory methodology, which aims to construct theories grounded in systematically gathered and analyzed data. Instead of beginning with a hypothesis, research using constant comparison allows for the emergence of concepts and connections as the data is collected.

The essence of constant comparison lies in its iterative process. Researchers collect data, analyze it, and then use what they learn to inform further data collection. This ongoing interaction between data collection and analysis ensures that the emerging theory is deeply rooted in the data itself. The process involves breaking down the data into discrete parts, coding them, and comparing these codes to find similarities and differences. Through this comparison, researchers can identify patterns and establish categories that form the basis of theory development.

The procedure of constant comparison includes several key steps: initial coding, where data is segmented into discrete parts; focused coding, where codes are synthesized and narrowed down; axial coding, where relationships between codes are established; and selective coding, which integrates the codes into a coherent framework that proposes a theory. Each step involves constant revisiting and comparison of data, codes, and categories, allowing for refinement and complexity to be built into the emerging theory. In other words, researchers compare segments of data with other data segments, codes are compared with other codes, and categories are compared with other categories. All this is done with the objective of assessing whether additional data, codes, or categories are contradicting, expanding, or supporting the emerging theory.

The method demands that researchers remain open to the data, allowing for flexibility and adaptability as new insights are gained. It requires meticulous documentation of how the analysis was conducted, as the rationale behind coding and category development must be transparent and trackable. This transparency is crucial for the credibility and transferability of the research.

Ultimately, constant comparison is a dynamic and rigorous analytical process. It's designed to handle the complexity of qualitative data, providing a structured approach to theory development that is directly informed by the research data. By using this method, qualitative researchers can produce well-grounded, nuanced, and relevant theories that offer deep insights into the phenomena being studied.

The constant comparative method involves looking at the data to create theories. Photo by NordWood Themes.

What is an example of a comparative analysis?

An example of comparative analysis using the constant comparative method can be illustrated in a study exploring the experiences of remote workers. Researchers might start by conducting in-depth interviews with a diverse group of individuals who work remotely. Initially, researchers transcribe and examine the interview data line by line, looking for keywords, phrases, or incidents that stand out—this is the open coding phase.

During this phase, a researcher might identify recurring themes such as "work-life balance," "communication challenges," or "adaptation to technology." As more data is gathered, the researcher begins the process of focused coding, where these initial themes are compared against new data, refining the themes to better fit the data set. For example, "communication challenges" might be broken down into "synchronous communication issues" and "asynchronous misunderstandings."

The next step, axial coding, involves examining the relationships between these focused codes. The researcher might find that "synchronous communication issues" often lead to a "sense of isolation," which in turn affects "work-life balance." These connections start to form the basis for a larger understanding of the remote work experience.

Finally, in the selective coding phase, the researcher weaves these relationships into a coherent theory that explains how remote workers manage their professional and personal lives. Perhaps the theory suggests that successful remote work depends on the development of new communication norms and self-regulation strategies to maintain balance.

Throughout the study, the constant comparative method ensures that each interview contributes to a deeper understanding of the remote work experience. The researcher continually revisits and compares the data, refining the analysis until theoretical saturation is established and a rich, grounded theory is developed that captures the complexities and nuances of working remotely.

This iterative process of data analysis, a hallmark of the constant comparative method, ensures that the resulting theory is not just a collection of data points but a reflective and comprehensive model of the real-world experiences of individuals.

Step-by-step guide to using the constant comparative method

Using the constant comparative method involves an intricate process of collecting and analyzing qualitative data to build a grounded theory. This method is not a linear journey but rather a cyclical one, where data collection and analysis occur simultaneously, each informing and enhancing the other. Here is a step-by-step guide to understanding how this method unfolds in qualitative research.

The first step is data collection, which is conducted without preconceived theories, allowing the data to guide the researcher. As the data—usually textual data from interviews, observations, or documents—is collected, the researcher begins the process of open coding. In this initial phase, the researcher reads through the data meticulously, identifying, naming, and categorizing phenomena found in the text. These categories are derived directly from the data, not from existing theories or hypotheses. Each piece of data is compared with the rest of the data, identifying similarities and differences, and is coded accordingly.

Following open coding, the researcher moves into the focused coding phase. Here, codes and categories are synthesized, with the researcher honing in on the most significant initial codes to explain larger chunks of data. This step involves a constant back-and-forth between the emerging categories and the data, ensuring that these categories are representative and comprehensive.

Next is the axial coding phase, where the researcher explores the relationships between categories by comparing each category with other categories. This involves a more conceptual level of analysis, looking at how categories can be related to form more abstract concepts. During this phase, categories are organized in a way that showcases their relationships, often indicating causation, intervention, and/or outcomes. The researcher repeatedly sifts through the data, comparing incidents, and refining categories as needed.

Finally, selective coding is where the substantive theory begins to take shape. The researcher integrates the categories to form a cohesive theory that is grounded in the data collected. This theory should provide a detailed understanding of the subject under investigation, based on the relationships between categories established in the axial coding.

Throughout each of these steps, the researcher must remain flexible and responsive to the data. As new data is gathered and analyzed, initial codes and categories may evolve, and the emerging theory may shift. This iterative process is at the heart of the constant comparative method, requiring the researcher to be constantly engaged with the data, comparing new data with existing codes, and revisiting categories in light of new evidence that might contradict, expand, or support the emerging theory.

In using the constant comparative method, the researcher's role is both systematic and creative, applying rigorous methods to the data while also being open to the insights that emerge. The goal is to ensure that the theory developed is not just data-driven but also analytically rich, providing a meaningful contribution to understanding the phenomenon under study. The end result is a grounded theory that offers a deep, nuanced understanding of the qualitative data, constructed through a methodical process of comparison and analysis.

Benefits of using the constant comparative method

The constant comparative method offers a plethora of benefits in qualitative research, particularly in its capacity to construct theories that are deeply embedded in the data. This method stands in contrast to quantitative analysis, which seeks to test hypotheses through statistical analysis, often missing the nuanced understanding that emerges from qualitative data.

One of the primary benefits of the constant comparative method is its dynamic nature. Unlike quantitative methods, which often require a rigid structure and a predefined hypothesis, the constant comparative method is fluid and adaptable. It allows the theory to emerge from the data itself, ensuring that the resulting theory is organically connected to the realities represented in the data. This flexibility means that the researcher can adjust the focus of the study as new themes and patterns emerge, leading to a more authentic and grounded understanding of the research subject.

Another advantage is the depth of insight that can be achieved. Quantitative analysis can tell us the frequency and correlation of certain phenomena but often fails to explain the "why" behind the numbers. The constant comparative method, by continuously analyzing and synthesizing data, provides a rich, detailed view of the context, processes, and meanings that underpin the data. This depth of analysis is particularly beneficial when exploring complex social phenomena that cannot be easily quantified or reduced to numerical variables.

The method can also enhance the validity of the research. By constantly comparing new data with existing codes and categories, the researcher is continuously validating and refining the emerging theory. This iterative process ensures that the theory is not only grounded in the data but also extensively cross-checked and corroborated throughout the research process. In contrast, quantitative analysis often relies on the statistical significance of results, which may not always capture the complexity of the data.

Additionally, the constant comparative method is inherently reflective. It requires researchers to engage deeply with the data, to think critically about their interpretations, and to be aware of their biases. This reflective stance is less pronounced in quantitative analysis, which often assumes a degree of objectivity in analyzing statistics. In qualitative research using constant comparison, the researcher's subjectivity is not a drawback but a tool for deeper engagement with the data.