Abstract
As a methodology emphasizing qualitative and quantitative integration throughout design, method, and technique, mixed methods research (MMR) is evolving with input from diverse research traditions and practices (Archibald, 2016). Participatory research, for example, can encourage new ways of thinking about data, impact, and interpretation, at times encouraging innovation and integration through real-time participatory analytic approaches (Alexander et al., 2021; Archibald, 2023). Influences from arts-based methodologies encourage new ways of engaging with divergent findings (Archibald & Gerber, 2018). Visual approaches to MMR (e.g., joint displays) offer benefits to data representation and integration (Guetterman et al., 2021; Reeping & Edwards, 2022). As the field continues to advance philosophically, methodologically, and practically, there is an ongoing need to develop tools and techniques to support integration, ideally while considering the potentials of visual and participatory MMR.
The MMR integration imperative has catalyzed the popularity of tools that aid this objective. Among the most common of such tools are joint displays, which are visual depictions of qualitative and quantitative data, and their relationship (Guetterman et al., 2021). Critically, the purpose of joint displays goes beyond their role as a communicative device, helping to unravel the constraints of cognition to move analytic processes toward meta-integration (Guetterman et al., 2021). However, joint displays are predominantly a researcher-led endeavor, constructed following respective analysis of each data type to generate mergers, linkages, and comparisons. Growing interest in participatory and collaborative MMR encourages attention toward tools and techniques that merge participant involvement in data representation and interpretation (Alexander, 2021; Archibald, 2023).
Although joint displays have received notable attention as an integrative visual tool in MMR, timelines have not. Timelines, defined as visual and temporally situated data representation tools, offer integrative possibilities for mixed methods researchers to move beyond the sum of narrative and statistical data consolidation (Fetters & Freshwater, 2015). Emerging and established scholars are likely to benefit from such additional tools as tangible supports for integration; as devises to move toward more thoroughly integrated MMR across a high diversity of data forms; or as support for exploring the complexities of longitudinal, temporally and contextually sensitive research problems.
In addition to these integrative benefits, timelines can involve participants to help generate rich contextual data and augment analytical depth (Archibald, 2023; Mannell et al., 2021). Here, participants can be provided with a visual timeline template to use as a data capture device for plotting experiences (e.g., visual icon reflecting emotional state and narrative descriptions) and other data points (e.g., heart rate and self-rating of anxiety) as they occur. Within this participant led model, temporal aspects of relevance (e.g., age and time of day) can be determined by the participant, by the researcher, or together in partnership, depending on the research question and study objectives. Such a study could occur prospectively or retrospectively and could include a variety of data forms (e.g., numeric through self-report measure and narrative and visual depictions of contextual factors and wellbeing) as in the fictious template example provided in Figure 1. Participant generated artwork or images, such as photographs of factors influencing wellbeing, provide additional avenues for visual and arts-based integration (Archibald & Gerber, 2018). Narrative data could be captured within the timeline itself or, following participant engagement with the timeline, could be used as a visual elicitation device to encourage depth and reflection during qualitative data collection. Opportunities for real-time data integration are also possible, reflecting a growing area of interest and future development in MMR (e.g., Alexander, 2021). Example template for a participant generated timeline.
Researcher generated timelines provide an alternative approach to the participant generated timeline. Here, researchers position various data in dialogue with each another, and with the temporal dimension however conceived (e.g., age, significant events, hours of the day) within the timeline following the respective analysis of each study strand. Such an approach enables opportunities for data transformation along the temporal axis (e.g., thematically informed time points of relevance on a patients trajectory of recovery from cancer diagnosis through remission) and other dimensions (e.g., conversion of step-counts, biometric markers, and global wellness ratings and dietary intake to narrative descriptions of health status through qualitizing), thereby advancing integration and enabling pattern identification across data forms (see Figure 2 for an example). When used in this manner, timelines offer support for integrative analysis, while also serving as an effective mode of dissemination that ideally communicates meta-inferences. Example of a researcher generated MMR timeline with meta-inference. Used with permission from Kamei et al. (2021).
Given their potential as an integrative visual tool with participatory potential, attention to the current uses and opportunities for timelines in MMR warrants further attention. In response, we conducted a methodological review to explore the uses of timelines in MMR and to illustrate opportunities for future development and application. We were interested in how, when, and for which purposes authors used timelines as visual devices to support an aspect of the research process, including data collection, analysis, integration, or dissemination, and what, if any, theoretical or methodological writing exists on MMR timelines.
Background
Timelines, at times also referred to as visual timelines (Goldenberg et al., 2016), data timelines (Villalba et al., 2018), lifelines (Gramling & Carr, 2004), journey maps (Ly et al., 2021), and originally life histories (Smith, 1994), serve as powerful tools for visually narrating aspects of experience along a chronological axis (Berends, 2011). Distinct from research planning timelines (Glegg, 2019), or those used to communicate procedural components of research such as study design, timelines can serve as data collection and data representation tools to aid communicative aims (Goldenberg et al., 2016). Timelines imbue events with significance and meaning while aiding with the recall and sequencing of personal experiences (Berends, 2011). Timelines can support comparative analysis across datasets and validate and enrich life narratives through the sequencing of significant past and present experiences—and even re-envisioned futures—in relation to specific time points. Further, timelines can contextualize research constructs, experiences or clinical issues within a broader social context or broader spectrum of events (Berends, 2011; Gramling & Carr, 2004; Patterson et al., 2012).
Originating in anthropology and sociology, timelines original use as life histories were often applied in tandem with other methods to describe biographical data and enable understanding of an individual’s life within the context of social structures (Gramling & Carr, 2004). Such life histories are unique in that they are customizable, are generated in several forms and lengths, and can accommodate varying focuses and perspectives (Smith, 1994). Aligned with this orientation, timelines provide a linear and visual depiction of life events or experiences in the chronological order of their occurrence (Gramling & Carr, 2004). Timelines may include interpretations of the events to facilitate understanding of participant experiences (Gramling & Carr, 2004). Within the MMR context, timelines could be used to anchor quantitative measures to specific time points to illustrate change over time in relation to context and other data forms, and thereby provide opportunities for real-time data integration, for example. Despite their potential, the use of timelines in MMR is not well understood; insights into current MMR applications can inform future development and thoughtful application.
Methods
We conducted a four-step methodological review of the MMR literature to comprehensively locate published academic articles on the use of timelines in MMR. The question guiding our review was: how, when, and for what purposes are timelines used throughout the MMR process, and what theoretical or methodological writing exists specific to MMR timelines? To accomplish this four-step review, we first hand-searched each volume and issue of the
To be included in the review, authors needed to have used a timeline during any part of a MMR study. We included articles that demonstrated qualitative and quantitative integration along with the use of timelines even if they did not self-identify as MMR. We excluded articles where timelines served only to describe a study’s chronology (e.g., sequence and timeline of study design) as this serves a different purpose from our objective.
Following title and abstract screening, the full texts of each identified article were reviewed to confirm relevance. With the included articles, we extracted data verbatim into a Microsoft Excel workbook using the following categories: publication title, first author, year of publication, journal name, methodological applications (timing of use and uses of timelines); and justifications, benefits, and challenges of use. To ensure the accuracy and agreement of the categorization process, a two-reviewer approach was adopted throughout. A second reviewer checked data extracted by one reviewer for accuracy; 100% agreement was attained. Extracted data were coded inductively; new codes were generated and applied to previously coded articles on an iterative basis. Codes were then clustered categorically and descriptively analyzed using measures of frequency (e.g., counts and percentages) to provide a comprehensive picture of the literature on timelines in MMR.
Results
1502 records were retrieved and reviewed for inclusion. Of these, 483 records were identified through hand searching the Flow chart of article inclusion.
Although we did not use date limiters in our search, the first occurrence of timelines in mixed methods was published in 1997 (Figure 4). A general upward trend of MMR timelines was noted, with a peak publication per year occurring in 2021 with 8 published articles. This general trend was also noted for the Publication of articles using timelines.
Justifications, timing, uses and benefits, and challenges of timelines were assessed for each of the 36 empirical articles (see Evidence Table 1, Supplemental Material for online appendix). Authors of 29 studies (81%) provided justifications for the use of timelines, with multiple justifications provided in 18 of these articles (62%). Authors most celebrated timelines for improving understanding of the research context (
Timeline use varied across substantive areas of application within the 36 empirical articles (Table 1, Supplemental Material for online appendix). Most of these articles (
Benefits and Challenges of Using Timelines
We examined the stated benefits of using timelines in MMR in each of the 36 empirical articles. The majority (
Compared to benefits, challenges were less frequently reported in the empirical articles (
Timing of Timeline Use
Across the 36 empirical articles, we examined when in the research process timelines were used. Most articles (
Data Collection and Data Types
Although all authors mapped data along the temporal axis of the timeline which is inherently numerical, the extent of qualitative, quantitative or arts-based data inclusion varied. Most commonly, authors used qualitative data collection tools (
Arts-based data collection (i.e., the use of creative arts of any form, including song, storytelling, and visual art, for example, to elicit tacit knowledge) within the timeline itself was present in two articles (6%). Hidding et al. (2020) mapped weekend and weekday photos to a visual timeline. Similarly, participants in the study by Sheridan et al. (2011) added photographs and other artifacts to the mixed methods timeline. Although participants were commonly asked to draw their own timeline, we did not qualify this as a unique arts-based data source and hence classified this use of timelines as participant generated rather than arts-based. One additional article (i.e., Chilisa & Tsheko, 2014) used arts-based methods in addition to their timeline but did not house the arts-based data within the timeline itself. Here, the authors leveraged Indigenous methods including song and story to inform a survey questionnaire and used a shield method involving drawing which participants used to dialogue with the timeline data.
The use of additional participant generated quantitative data collection within the timeline was less prominent (
Applications of Timelines
The practical applications of timelines were examined across all empirical articles. Most of these articles (
Theoretical Writing on MMR Timelines
Three theoretical articles were also included and analyzed. These articles were situated in the substantive area of methodological advancement. The first article by Alexander et al. (2019) emphasized the key role of visuals, such as timelines, in supporting discussions. Here, Visual Replay Methodology represents an advancement in the investigation of discourse patterns across small-group discussions and places distinct value on the power of visual aids in leveraging data integration (Alexander et al., 2019). The second article by Newton-Levinson et al. (2020) presents timelines as a visually stimulating and accessible way to integrate data in the context of program evaluation. Here, timelines are seen as complementary to many methodologies and can be used to create rich and holistic data visualizations (Newton-Levinson et al., 2020). Finally, Creamer (2021) highlights the versatility of timelines, noting that they support the dimensionality of data while also promoting an interactive engagement between different data types. Creamer (2021) regards timelines as an adaptable, integrative approach that encourages richness and the inclusion of context in the data. Each of the theoretical articles included supports the use of timelines as a means of visually augmenting data, facilitating data integration practices, and enhancing the overall quality of the data, thereby extending the empirical findings (Alexander et al., 2019; Creamer, 2021; Newton-Levinson et al., 2020).
Discussion
Timelines in mixed methods are relatively emergent in status, but interest in their development and application appears to be growing across mixed methodology journals as well as empirical journals with a propensity for publishing mixed methods articles. To better understand their potential, this review utilized a rigorous and comprehensive four-step approach to explore the use of timelines in MMR and to provide insights into their current applications. Prominent in the findings from the 36 empirical articles are the notable variations in the application of timelines within the same research phase (e.g., data collection). Timelines show malleability in their use and areas of application and have capacity to support and house multiple data forms (e.g., biometric data, participant diaries, critical events, and hospital data). Authors reported numerous positive assessments related to the use of timelines while infrequently reporting associated challenges. These results illustrate that although timelines are increasing in popularity in MMR, there remain several opportunities for their continued refinement and enhancement.
Providing Transparent Justifications for Use
Justifications are a key to transparent and internally coherent research across qualitative and MMR traditions (Archibald, 2016; Carter & Little, 2007; Caruth, 2013). Although most authors present some form of justification, they were often multifaceted and at times provided complex or ambiguous answers to the fundamental question “why use timelines in MMR?” Challenges regarding the inconsistent reporting of justifications for use of mixed methods has been highlighted at the level of research design (e.g., O’Cathain et al., 2007) and technique (e.g., Archibald, 2016) and so while not a recent observation, this finding highlights persistent inconsistencies in this domain. A clear rationale for timeline use, an explicit indication of the timing of use as a data collection instrument, and a clear picture of the mode of facilitation (e.g., researcher or self-administered and indication of prompts) is imperative to enhancing transparency, practicality of use, and for supporting methodological development.
Affordances and Challenges of Timeline Use
Developing and applying MMR research tools and techniques requires insight into their affordances and challenges. Empirical examination of a tools’ utility and acceptability, for instance, can inform appropriate contexts of application, highlight domains for further amendment (e.g., improved facilitation and instruction for accurate participant generated timeline development), and provides a basis for claims about the merits of a particular tool (Archibald et al., 2024). Results from this review show that although most authors report on the benefits or challenges of using timelines in MMR, only a few empirically examined these areas. Further insights into these benefits, including empirical assessments of researcher and participant perceptions, when possible, would further inform methodological development.
In contrast to the commonly acknowledged advantages of timeline use which included enhanced communication, data visualization, and contextualization, the challenges associated with their use were substantially less reported. The most reported challenge was that timelines are limited in their comprehensive presentation of data. Difficulties and variabilities with data interpretation were also of concern, with authors noting the potential for inconsistencies and limitations in capturing the intricacies of life experiences. The dearth of empirical evaluation of tinelines and the associated lack of reporting related to its challenges is reflected in other areas of methodological development and writing. For instance, our previous work examining the viability of videoconferencing for qualitative data collection also emphasized the need to measure and gather data on the benefits and challenges with new methodological approaches (Archibald et al., 2019) more intricately. Similarly, a recent mixed methods approach to priority setting in youth and family mental health highlights the need for questions that directly assess the challenges and benefits for participants in applying a new method for priority setting, to identify the comparative utility of a specific tool (Archibald et al., 2023). In essence, a more comprehensive and transparent examination of the challenges and benefits of new methodological applications is imperative to shed light on the applicability of emerging methods, such as the use of timelines, for MMR.
Supporting Visual, Longitudinal and Technologically Mediated MMR
The increased application of timelines is consistent with the growth of interest in visual data and methods in MMR more generally (Guetterman et al., 2021; Mannell et al., 2021). Within the historical landscape of qualitative research, visual data has traditionally encompassed a diverse array of mediums such as photographs, personal artifacts, films, and illustrations, all employed to encapsulate the essence and visual representation of the subject under examination (Monico et al., 2020). This concept of the visual is inclusive of approaches like timelines. However, both the results of this work and previous research raises concern over the potential loss of the richness of life stories due to the summarizing nature of visual methods (Patterson et al., 2012). For this reason, timelines are likely most effective when used in tandem with additional, comprehensive, data sources. Depending on the research question and design, these may include in-depth narrative interviews (Patterson et al., 2012), or arts-based modalities (e.g., photographs and participant drawings)—the latter of which is underrepresented in the mixed methods timelines literature and the MMR literature more generally (Archibald, 2018).
Despite limitations in the extent of data that can be visually portrayed two-dimensionally, mixed methods timelines can represent time-based changes in experiences or variables in a visually stimulating and accessible format (Newton-Levinson et al., 2020). Though time as a quantitative variable is an inherent attribute of timelines, our review demonstrated that additional quantitative data sources are infrequently collected with research participants as part of the timeline activity. As such, there is untapped potential to incorporate more quantitative, biometric (e.g., heart rate), and mixed data sources into timelines, to assist in visualizing and understanding changes in such data over time (e.g., test-retest data and repeated measures for longitudinal data) (Harrison et al., 1994). Cross-over analytics, wherein techniques from one tradition, are used to analyze data from another tradition (Hitchcock & Onwuegbuzie, 2020) and also hold potential in this regard. Here, new quantitative variables created from qualitative data could be generated and plotted alongside quantitative results to enable an alternative capture of data complexity and changes occurring over time. This may provide insight into the affordances and limitations of analytic approaches, which is of interest to the MMR community.
Dissemination and Safeguarding
Timelines were regarded favorably by authors in the included studies, with noted benefits to data comprehensiveness and participant engagement. However, the strengths of timelines in promoting a meaningful dialogue between different data sources and exploring the potentials for improved research dissemination were not a focal point in this dataset. Timelines, like arts-based data collection methods such as body mapping (i.e., wherein participants visually portray experiences within an outlined body image) or digital storytelling (i.e., wherein participants create multimedia stories in response to a research question), for example, have an inherent functionality aligned with the knowledge translation movement (i.e., the science concerned with the ethically sound application of knowledge). Their visual principles resonate across these domains, highlighting potential to serve dual roles as both data collection tools and knowledge translation or dissemination devices (de Jager et al., 2016; Park et al., 2021).
Although timelines are powerful tools for visualizing data in MMR and often involve participant reflection and experiential representation, the emotional impact on participants engaged in the process is often overlooked. This finding contrasts some studies in storytelling and journey mapping, where emotional aspects of engagement have been more thoroughly examined (Soundy & Reid, 2019). Insights from these fields highlight the importance of a more nuanced examination of emotional safeguarding when using participant generated MMR timelines, including the impact of the data collection process on participants. Comparably, involving participants in the interpretation of timelines may provide insights into their impact while opening space for collaboration (Archibald, 2023). By incorporating the perspectives and experiences of those directly involved, researchers can gain valuable insights to enhance the richness of the data but also mitigate the potential for misinterpretation (Mannell et al., 2021). This participant-centric approach contributes to methodological rigor while laying the groundwork for future research that includes a more comprehensive understanding of the emotional dynamics of visual, participatory research.
Contribution to the Field of Mixed Methods
MMR continues to attend to the integration challenge, seeking both theoretical understandings and methodological advancements at the levels of design, method and technique, and critically considering the role of visual and participatory tools in the context of this objective. Visual methods have been a key component of these discussions. Timelines, like joint displays, for instance (e.g., Guetterman et al., 2021), have potential to bridge integrative, visual, and collaborative spheres. This review supports a better understanding of the use of timelines within MMR and encourages their continued application, opening future possibilities related to integration, longitudinal design, and visual participatory methods (e.g., real-time validation), through an engaging and inherently mixed data collection tool and range of associated techniques for application.
Challenges and Future Directions
Timelines are a growing area of interest in the mixed methods community but are nascent in status. With this emerging status exists an opportunity for further expansion and development. Currently, the range of diversity noted in the application of timelines is not a shortfall of the approach, nor is uniformity and methodological rigidity aligned with the creativity desirable for innovation and for the advancement of MMR. Yet improved documentation of the processes surrounding the use of timelines—including why, how, and when authors use timelines—would help inform rigorous use and application across future contexts. Aligned with a global movement toward improved research reporting as evidenced by the proliferation of reporting guidelines, including mixed methods reporting guidelines (e.g., for: rehabilitation health sciences research, Tovin & Wormley, 2023; counseling research, Leech & Onwuegbuzie, 2010), authors utilizing timelines should report the core components related to their use. These could include the timing (e.g., wherein the research process) and justification for timeline use (e.g., providing more context to aid interpretation), the role of timelines in the research process (e.g., data collection device and dissemination tool), the nature of their use in data collection (e.g., as a synchronous data collection method or data plotted asynchronously), method of facilitation (e.g., researcher administered and participant self-administered), frequency and timepoints of use (e.g., every month for four months), and observed and measured/assessed benefits and challenged or limitations from both researcher and participant perspectives. Such comprehensive reporting helps improve the use and development of emerging tools and facilitates a more discerning and nuanced understanding of their impact on the research landscape.
Timelines in MMR can enhance the visual representation of temporal data across diverse study landscapes and promote consideration of alternative interpretations and planes of data representation (e.g., concurrent dimensions of experience relative to time may provide new insights). Current applications of timelines focus on linear and two-dimensional forms. However, digital advancements may enable more complex representations, reflecting multiple planes of experience and data. This would reflect a new avenue of development, one that dovetails mixed methodological and digital advancements and emphasizes the visual potentials of representation. Such exploration could help respond to the criticism of timelines as reductive and limited in their representational ability. This would also allow for the integration of additional data forms with utility for accessing nuanced and often unconscious components of lived experience, such as arts-based research methods. Of note, we observed on at least one occasion that participant generated timelines were framed as an arts-based approach, due to the requirement that participants draw timeline graphs (e.g., Looman et al., 2022). However, using formulaic drawing to create graphical representations, although aligned with visual methods, does not evoke the expressive and creative requirements mandated by arts-based data collection and should not be classified as such.
The use of participant generated timelines was common in this dataset. However, when a timeline is not participant generated, there remain meaningful opportunities for heightened interpretation of the data (e.g., participant validation) and opportunities for visual presentation and discussion of mixed data within the timeline. The timeline is a method of visual integration; iteratively or definitively generating and integrating participant perspectives or interpretations based on the presentation of mixed data sources would provide creative opportunities for participant involvement in mixed analysis. Further consideration of the techniques, timings, approaches and implications of the various means of participant engagement with MMR timelines is a fruitful area for future study. More generally, future research should continue to explore the applicability and integration of visual methods in MMR as this will continue to support a deeper understanding of the methodological diversity that can be fostered using this integrative tool.
Conclusion
Timelines are tools for collecting a range of data and sharing these data visually. They anchor temporal events with other data in a graphical format. Visual methods like timelines offer opportunities to elicit and validate participant’s lived experiences in a context-sensitive manner. By nature, timelines offer the MMR scholar numerous access points for integration, and depending on use, can function as inherently mixed and participatory data collection and dissemination tools. Future work should consider methodological opportunities enabled by their use (e.g., mixed data collection, integration of digital research methods, and multidimensional digital representation) and report more transparently and consistently the affordance, challenges, and reasons for using timelines across disciplines and study contexts. As timelines hold potential as a highly integrative, analytic, we invite other researchers to continue to explore the empirical and theoretical uses of timelines as an emergent visual method within MMR.
Supplemental Material
Supplemental Material - Examining the Integrative Potential of Visual Timelines in Mixed Methods Research
Supplemental Material for Examining the Integrative Potential of Visual Timelines in Mixed Methods Research by Mandy M. Archibald, Stephanie J. Mazzon, and Michaela A. Bourque in Journal of Mixed Methods Research
Footnotes
Acknowledgments
Declaration of Conflicting Interests
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References
Supplementary Material
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