LEUKOS Editor Report, Reflections, and Farewell

1. Introduction

This is my last issue as editor of LEUKOS, a position I have held since 2011. Given my longevity in this role, it seems appropriate to share some parting reflections on LEUKOS’s recent past. As LEUKOS transitions to a new leadership and administrative model, I hope that insights derived from this reflection will support the journal’s next phase of development. This editorial summarizes historical events, journal-level performance statistics, context for the performance trends, and what I believe have been the keys to LEUKOS’s current success.

LEUKOS was founded in 2004 based on ideas from Prof. Mark Rea, who imagined reforming the Journal of the Illuminating Engineering Society in an online format that would operate separately from the paper submission and review process associated with the IES Annual Conference. Prof. David DiLaura was the first editor of LEUKOS, a position he held through 2011. Prof. DiLaura worked with Operations Advisory Board members Rita Harrold, Richard Mistrick, Gary Steffy, and Jennifer Veitch to define operational details, journal policies, and goals. Prof. DiLaura established high standards for editorial quality that I was fortunate to inherit and committed to maintain. His 2006 Report to the Readership provides additional background about the founding of LEUKOS and performance during its early years (DiLaura 2006).

2. LEUKOS performance report

Over the past decade, LEUKOS has undergone significant growth, expanding in influence and international reach. To appreciate how and why that occurred, it is relevant to consider the changes in the publishing landscape and actions taken to drive performance. Like many research publications associated with professional societies in the early 2000s, LEUKOS was disseminated only through the society’s website. Reaching a limited audience and with contributing authors mostly from North America, LEUKOS’s impact was low. When I became editor in 2011, LEUKOS had a 5-year Clarivate Journal Impact Factor (JIF) of 0.57 and received an average of 29 new submissions per year.

Figures 1 and 2 present trends for salient journal-level performance measures, including the most common citation performance indices, total citations, article downloads, and percentile performance based on citations. Upward trends can be observed across almost all measures. In 2021, the Clarivate JIF reached 3.44, and the Clarivate Journal Citation Indicator (JCI) and Scopus CiteScore both placed LEUKOS is the top quartile of journal performance. Table 1 and its caption summarize the submission trend since 2005, and manuscripts published since 2014. Even accounting for year-to-year fluctuations, since 2014 LEUKOS has received and maintained twice as many submissions compared to preceding years, and printed pages have more than doubled. Discussed next are three interconnected aspects that have driven these performance trends: 1) increasing visibility and discoverability, 2) growing submission quantity, and 3) focusing on quality.

Fig. 1. LEUKOS journal-level performance trends. Consistent the San Francisco Declaration of Research Assessment (DORA 2012; Taylor & Francis 2021), LEUKOS discourages quoting a single journal-level performance measure because any one measure tells only a part of the story of a journal’s quality and impact. Included here are (a) Clarivate’s Journal Impact Factor (JIF), (b) JIF without self-citations, (c) 5-year JIF, (d) Scopus CiteScore, (e) Total citations per year, and (f) Total downloads per year. Some of these measures are best understood with explanation of how they are computed and contextualization. The JIF (Clarivate 2022) and CiteScore (Scopus 2022) are lagging indicators of impact based on citations. Clarivate generally releases JIF reports in July for the preceding calendar year. The 2021 JIF is computed as (citations in 2021 to items published in 2019 (93) + 2020 (110) = 203) ÷ (citable items in 2019 (20) + 2020 (39) = 59) = 203 ÷ 59 = 3.44. The Clarivate JIF without self-citations removes from the numerator any citing articles that were published in LEUKOS. The Clarivate 5-year JIF is computed with the same formulation, but with a trailing period of five years rather than two years. Scopus generally releases CiteScore reports in the spring for the preceding year, complemented by a CiteScoreTracker that is updated monthly. The 2021 CiteScore is computed as (citations from 2018 to 2021 = 526) ÷ (documents from 2018 to 2021 = 79) = 526 ÷ 79 = 6.7. As of November 5, 2022, the CiteScoreTracker for 2022 is: 674 citations ÷ 90 documents = 7.5. (e) illustrates steady increase in total citations per year. In 2021, there were a total of 697 citations. Of those, 203 citations were to articles published in 2019 and 2020, contributing to the 2021 JIF. The other 494 citations were to articles published in 2021, or between 2004 and 2018. This suggests that LEUKOS content is standing the test of time, with broadening impact. (f) begins in 2014 since that was the first full year of hosting by Taylor & Francis.

Fig. 2. This figure illustrates three measures of percentile performance. LEUKOS is included in two Clarivate Science Citation Index Expanded (SCIE) categories, Optics, and Construction & Building Technology. LEUKOS is included in the Scopus category of Physics and Astronomy, under the heading Atomic and Molecular Physics, and Optics. In 2021, LEUKOS was ranked 27/68 (61%) in the Clarivate category of Construction & Building Technology, 34/101 (67%) in the Clarivate category of Optics, and 39/205 (81%) in the Scopus category of Atomic and Molecular Physics, and Optics. The percentiles shown in (a) are averaged across the two Clarivate categories. (b) illustrates LEUKOS’s Journal Citation Indicator (JCI) percentile, which was retroactively published by Clarivate for the first time in 2021. The JCI is normalized for the widely varying rates of publication and citation in different disciplines. It is intended to better contextualize performance – e.g., the SCIE Optics category includes journals in photonics, nanoscience, lasers, quantum technologies, optomechatronics, and other topics that represent larger fields of study and are not directly comparable to LEUKOS. The percentiles shown in (c) are based on the Scopus CiteScore, which originated in 2011. LEUKOS’s five-year trailing average across all three measures is 75.2%. Taken together, on these measures of citation performance, LEUKOS is in the lower portion of the top quartile or the upper portion of the second quartile.

Table 1. Dark gray background (left): Manuscripts received between 2014 and 2021, subdivided by manuscript type and by new or revised submissions. During the 9-year period between 2005 and 2013, LEUKOS received an average of 29 new submissions per year (Max = 32, Min = 21, Std Dev = 4.2). Light gray background (right): Page budget and actual pages printed from 2014 to present. Volume 10 is the first volume of LEUKOS that was published with Taylor & Francis. Actual pages include front matter and the table of contents.

	Manuscripts Received										Manuscripts Published
Year	New or Revised	Brief Communication	Engineering Development	Letter to the Editor	Lighting Application	Review Article	Scientific Research Results	Tutorial Article	Subtotals	Totals	Volume	No. Peer Reviewed Articles	No. Editorials & Letters	Page Budget	Actual Pages
2014	New	2	6	0	4	8	28	1	49	86	10	16	4	320	239
	Rev.	2	4	0	0	8	22	1	37
2015	New	2	2	1	3	3	19	1	31	74	11	16	4	320	233
	Rev.	2	7	0	2	7	25	0	43
2016	New	1	5	0	7	5	39	3	60	93	12	17	7	320	246
	Rev.	0	2	0	0	3	25	3	33
2017	New	3	5	0	15	3	44	1	71	108	13	16	6	320	244
	Rev.	0	3	0	1	2	30	1	37
2018	New	2	4	0	12	3	50	3	74	174	14	16	4	320	278
	Rev.	4	10	0	13	10	58	5	100
2019	New	1	4	1	11	8	31	2	58	99	15	20	4	320	320
	Rev.	0	0	0	3	4	32	2	41
2020	New	5	2	0	3	4	49	2	65	126	16	21	5	320	317
	Rev.	2	4	0	5	8	41	1	61
2021	New	3	4	0	5	6	33	0	51	95	17	22	4	384	393
	Rev.	0	5	0	0	2	37	0	44
2022	New	3	0	0	7	4	38	0	52	109	18	27	4	520	515
	Rev.	2	5	0	9	5	36	0	57

2.1. Increasing visibility and discoverability

As part of the strategy to increase visibility, I engaged in extensive outreach with the international lighting research community during my early years as editor, a practice I maintained throughout my tenure. This bottom-up grass-roots approach enabled one-on-one and small-group discussions, where I listened to concerns, offered assurances, shared my vision for LEUKOS, and invited engagement. I endeavored to raise visibility among established researchers by inviting participation as authors and reviewers. I also participated as a review panelist in numerous LumeNet (2022) conferences and Daylight Academic Forum (2022), where I interacted with more than 100 PhD students. This was synergistic with my personal interest in supporting PhD students and their research, while raising awareness about LEUKOS as a vehicle for scholarly dissemination. I am optimistic that many of the early career researchers who have published work in LEUKOS will have career-long relationships with the journal.

As a key step to address discoverability, IES entered a publishing agreement with Taylor & Francis in advance of the 2014 volume year (Houser 2013). Taylor & Francis has since provided much of LEUKOS’s back-office support, including providing the submission and review portal, typesetting, online hosting, marketing assistance, management of library subscriptions, indexing and digital object identifier (DOI) management, support with performance analytics, and search engine optimization. As part of the initial transition, Taylor & Francis retro digitized the Journal of the Illuminating Engineering Society, with all 33 volumes (1971–2004) archived online alongside LEUKOS. IES retains sole responsibility for establishing editorial policies including LEUKOS’s objectives and scope, forming LEUKOS’s leadership and administrative structure, managing peer review, and providing content including accept and reject decisions. IES and Taylor & Francis have a collegial, cooperative, and mutually supportive partnership.

2.2. Growing submission quantity

As shown in Table 1, LEUKOS received a substantial increase in new submissions in 2014, then again in 2016 through 2018. This was in part due to a positive relationship between visibility, discoverability, impact (e.g., Clarivate’s JIF), and submissions. As more people learned about LEUKOS, and as the performance trends began to tick upward, LEUKOS became a more attractive journal, with growth coming primarily from outside of North America.

Additionally, the publication of several special issues contributed to increased submissions. The increase in new submissions in 2014 was related to the Special Issue on Color Rendition, which was completed in 2015. The increase in submissions in 2017 and 2018 was related to the Special Issue on Lighting Research Methods and Special Issue on Museum Lighting, both completed in 2019. These special issues were substantial undertakings, each multi-year projects with special attention to content curation. Each required close collaboration with guest editors. Two of the three included collaboration with conference organizers and securing resources for open access publication fees. The three special issues contain many of LEUKOS’s most highly downloaded and cited articles.

The growth in quantity is also reflected in page budget increases. Table 1 summarizes the page budget and actual pages printed between 2014 and 2022. Between 2014 and 2018, there was not enough content of sufficient quality to fill the page budget allowance, while also building a reserve of accepted articles. A reserve is important because it removes time pressure from the publication process, enabling the editor to be more vigilant in requiring revisions to manuscripts that are working toward acceptance and permitting more freedom in rejecting manuscripts of insufficient quality. Between 2014 and today, the acceptance rate has been around 35%; LEUKOS has never had a target acceptance rate, instead accepting all manuscripts that are an appropriate topical fit and meet standards for scientific merit and presentation clarity. Placing manuscripts in a reserve does not delay publication. Accepted manuscripts are given permanent DOIs, are citable, and appear online in the “Latest Articles” section of the LEUKOS website.

Having built a sufficient reserve, from 2019 onward LEUKOS has used the entirety of the page budget. In 2021 the page budget increased from 320 to 384 pages, and in 2022 increased again to 520 pages. For 2023, Taylor & Francis and IES have agreed to change from a maximum page budget to a minimum number of articles, with a Volume 19 (cover year 2023) minimum of 5 articles per issue, though 6 articles per issue are expected. The shift from a page budget to article minimum enables authors to include appendices in typeset manuscripts, material that would have otherwise been allocated to supplemental material (Houser 2015). LEUKOS’s new editorial team will inherit a reserve that is large enough to populate at least the entirety of Volume 19 (cover year 2023) and a portion of Volume 20 (cover year 2024). The reserve will support LEUKOS’s transition, enabling the new editorial team to appropriately manage the size of the reserve and sustain measures of journal performance while settling into a stable operation.

2.3. Focusing on quality

It may seem that quality has already been discussed in the form of journal-level performance measures. Indeed, many researchers prioritize journal-level performance measures when choosing where to submit their work. Some academic hiring committees and promotion and tenure committees use journal-level performance measures to evaluate personnel performance. While the rationale for these practices can be questioned, editors must nevertheless recognize that measures of citation impact are employed by some constituencies as a proxy for quality. While an ethical editor has no direct control over measures of citation impact (Houser 2017), an editor has substantial indirect control of long-term performance trends through daily and weekly actions. A commitment to quality includes article-level decisions, attention to detail during copy-editing and typesetting, and communication that supports good-natured relationships.

The decision-making editor is responsible for reject and accept decisions. To guide these decisions, the editor (or editorial team) establishes standards for scientific merit, credibility, presentation clarity, topical fit, and novelty. These considerations all contain some degree of subjectivity. To support informed judgments, the decision-making editor seeks counsel from reviewers and when required, from other editors. Reviewer selection demands effort. Flimsy reviews do not help authors improve their work and do not help the editor make informed decisions. Reviewers must first be technically proficient in the topic of the manuscript, but that alone is not enough. Helpful and credible reviews are incisive, offer actionable insights, are written with a constructive tone, and are performed within a few weeks of the invitation (Veitch et al. 2019). Reviewing is voluntary, and not all reviewers are able or willing to deeply invest in the peer-review process. Since the quality and credibility of reviews are uneven, an editor must weigh the veracity and integrity of each review, including potential conflicts of interest. The editor might confidentially track reviewer performance to guide future reviewer selection. Reviews are independent, and reviewers do not always agree with each other about the merits of a manuscript. The editor will not always agree with every part of a reviewer’s commentary. Because of inherent irregularities in the peer-review process, reject and accept decisions are not administrative decisions. They are always nuanced scholarly decisions, informed by expert reviews, and by editorial judgment. In cases where there is disagreement, the editor is responsible for good-faith adjudication of differences and ensuring that the positions of all sides have been heard, understood, weighed, and responded to. Though the peer-review process has communal inputs, the decision-making editor has singular responsibility for accept and reject decisions. Even while interacting with reviewers and authors, the editor is doing so with empathy for readers, endeavoring to ensure that accepted manuscripts have the topical fit, clarity, completeness, and scientific merit to be well-received by readers. Good content is foundational.

Central to LEUKOS’s success has been clear communication, humanity, and rapport at every step in the review, decision-making, and publication process. I am mindful of the significant personal effort that authors invest in their manuscripts and reviewers invest in their evaluations. Though editors have neither a carrot nor stick, they influence engagement by establishing a journal’s culture. For me, this has included setting high expectations, offering clear guidance, validating reviewer and author contributions, and expressing sincere appreciation. For example, while modern review systems include boilerplate templates for most types of correspondences, generic text will almost always benefit from revisions that are contextualized to the specific situation. Rather than simply directing an author to comply with journal formatting instructions, a letter can instead describe each revision required. Rejection letters also demand care, written to constructively explain why a manuscript has been rejected, with a tone that preserves the dignity of the authors. LEUKOS reviewers always receive a thank you letter that includes a redacted copy of the decision letter and comments from other reviewers. Person-to-person connections like these encourage engagement and grow a supportive community around the journal.

3. Parting thoughts

It is rewarding that so many have come to view LEUKOS with a sense of ownership and belonging, a journal worthy of their investment. For authors, this means they would be pleased for their work to appear in LEUKOS. For reviewers, this means they anonymously invest time and expertise to help unknown authors improve their work. For readers, this means finding knowledge, inspiration, and novelty in the pages of LEUKOS, often leading to citations and follow-up research. LEUKOS has welcomed the global community of lighting researchers, with 68% of accepted manuscripts between 2014 and 2022 coming from outside of North America. LEUKOS has served as IES’s most visible contribution to the global lighting community, becoming an important vehicle of dissemination in the global discussion about lighting science and applied research in light and lighting.

In retrospect, LEUKOS gave me the opportunity to develop fulfilling professional relationships. Some relationships began with invitations to prospective reviewers and authors. Others were initiated by authors with pre-submission queries or submitted manuscripts. Associate and guest editors have supported my work with insight and counsel. Taylor & Francis has been an exceptional publishing partner. IES leadership empowered and entrusted me to develop LEUKOS, provided resources, understood the long game, and accepted that some activities would take years before they translated into outcomes.

Looking ahead, there is more that could be done to expand LEUKOS’s value to authors and readers. For example, LEUKOS is not indexed in PubMed, the US National Library of Medicine’s index of biomedical literature. As lighting research continues to expand into health, PubMed indexing is more appropriate than ever since it will help LEUKOS reach a broader audience. A renewed focus on topically relevant special issues could enhance LEUKOS engagement with authors at the forefront of discovery. Additional curated content could support the lighting community’s topical interests while improving journal-level performance metrics. LEUKOS content could also be disseminated in alternate ways, as with IES supported webinars that reach new audiences. LEUKOS could also strategically align with select conferences and research symposia, including conferences sponsored by IES and by partnering with other organizations.

It has been a privilege to serve as editor of LEUKOS. While I will miss my frequent interactions with the global community of lighting researchers, I look forward to continuing my active engagement as a dedicated researcher and colleague. I will continue to support LEUKOS as an author, reviewer, and reader, and invite you to do the same. As I bid my farewell, I wish the best to the new editorial team, with optimism that LEUKOS’s best days are ahead.

Acknowledgments

It is impossible for me to acknowledge everyone that has supported LEUKOS during my time as editor, but there are four people that warrant special recognition. It was a privilege to inherit the helm from David DiLaura and reassuring to know that I could always rely on his candor and counsel. Bill Hanley believed in my vision to grow LEUKOS, supporting the partnership with Taylor & Francis, and trusting my assurances that reimbursement of international conference travel was a worthy investment, even though it took years to see the positive effects. Associate Editors Steve Fotios and Jennifer Veitch have been my most trusted colleagues, the people that I have consulted first when in need of advice. They are wise, generous, and supportive—not just toward me personally or only to LEUKOS, but toward the whole enterprise of lighting research and dissemination.