Research

drops

cervimetry

apgar score

hist & phil of measurement

measurement heresy

clinimetrics

Drops: A Nonstandard Unit

The “Uncertain Method of Drops”: How a Non-Uniform Unit Survived the Century of Standardization

SISS Meets Early Careers, Italian Society for the History of Science (SISS) Armel Cornu and Rebecca Jackson, 2 April 2024.

Publications on Drops

• Cornu, Armel, Sarah Hijmans, and Rebecca L. Jackson. 2026. “The Drop and the Metric System: How an Unruly Unit Survived Revolutions,” Annals of Science, 1–28. doi: 10.1080/00033790.2026.2636886.
  • Winner of 2025 Trevor Levere Best Paper Prize.
  • The first historical account of the “drop” in French chemistry and pharmacy during metrification. We showed that nonstandard units and qualitative indications continued to be used in processes of quantification and for correctly operating instruments.
• Jackson, Rebecca L. 2021. “‘The Uncertain Method of Drops’: How a Non-Uniform Unit Survived the Century of Standardization.” Perspectives on Science 29 (6): 802–841. doi: 10.1162/posc_a_00395.
  • A novel historical study of the “drop” as a successful nonstandard fluid unit in the Anglo-American context, broadening understandings of measuring and knowledge-making by showing how nonstandard units operate as essential tools for communicating heuristics. Awarded the Maurice Daumas Prize from the International Committee for the History of Technology (2023).

Cervimetry

Feeling Centimeters of Dilation: Why You’ve Never Heard of a Cervimeter

Lunchtime Lecture, Science History Institute, Philadelphia, PA, USA Rebecca Jackson, 21 March 2023.

Cervimetry Publications

• Jackson, Rebecca L. 2025. “Constructing Centimeters: Emanuel Friedman’s Cervimeter and the Dilatation-Time Curve.” Bulletin of the History of Medicine 99 (1): 51–93. doi: 10.1353/bhm.2025.a963726. Open access link here.
  • This history of the Friedman standard for “normal” labour shows that defining active labour based on centimeters of cervical dilation violated Friedman’s own original beliefs about the individuality of healthy labours. Awarded Graduate Student Essay Award Honorable Mention from Forum for the History of Health, Medicine and Life Sciences (2022).
• Jackson, Rebecca L. 2023. “How the Cervix Killed the Cervimeter: A Nonstandard Story of Successful Measurement.” Measurement 222: 113652. doi:10.1016/j.measurement.2023.113652.
  • I uncovered the historical role of the cervimeter, the instrument behind Emanuel Friedman’s eponymous model of cervical dilation over time during labour, which became the global standard for “normal” labour in the late-20th century. I explain 70 years of failed attempts at creating an instrument for measuring the cervix and the philosophical reasons for appreciating the manual method of measurement as epistemically superior.
• Jackson, Rebecca L., and Merlin Wassermann. 2022. “When Standard Measurement Meets Messy Genitalia: Lessons from 20th Century Phallometry and Cervimetry.” Studies in History and Philosophy of Science 95: 37-49. doi:10.1016/j.shpsa.2022.06.014.
  • Co-written with a science journalist, we unpack the history of why the measurement of the cervix and the penis was never successfully standardised. This research won the Interdisciplinary Organized Session Prize from the International Society for the History, Philosophy, and Social Studies of Biology (2023).
• Gross, Mechthild M., and Rebecca L. Jackson. 2026. “The History of the Early Labour Phase: Women’s Experiences Embedded in Methodological Considerations,” in Early Labour and Maternity Care: Research for Practice, edited by Vanora Hundley and Helen Cheyne, 18-34. Routledge. doi: 10.4324/9781003507192.
  • Co-written with a midwife researcher, this paper overviews the shifts, from the 20th century to today, in how the early stages of labour (often called “latent” labour) have been measured, reflecting methodological and social changes in views on the labouring body.

The APGAR Score

The Apgar Score and Race

• Jackson, Rebecca L. 2025. “The Apgar Score and Race: Why Healthy Babies Are Supposed to be ‘Pink’.” History and Philosophy of the Life Sciences 47 (4):45. doi: 10.1007/s40656-025-00693-3.
  • I investigated whether a globally-used score for newborn wellness has inherited the racial biases of its beginnings in 1940s-50s USA. While the assessment of newborn skin tone demands revised terminology, the main source of injustice is likely the Apgar Score’s misinterpretation and misuse when conflating its epidemiological and clinical roles.
  • I outline how this case demonstrates that neither representational theory of measurment nor traditional psychometric validation seems to account for the historical trajectory of clinical measures like the Apgar Score.

History and Philosophy of Measurement

• Jackson, Rebecca L. and Luchetti, Michele. 2027 [in press]. “History and Philosophy of Measurement: Past, Present, and Future Integrations,” for The Blackwell Companion to the Integrated History and Philosophy of Science, ed. Yafeng Shan. Wiley.

  • We co-wrote the first account of the origins, state-of-the-art, and future potential of integrated history and philosophy of measurement as a subfield. We overview methodological strategies and underutilised approaches. Received Runner-up Essay Prize in History and Philosophy of Science from International Union of History and Philosophy of Science and Technology (2025).

• Cristalli, Claudia and Rebecca L. Jackson. 2023. “From Postal Scale to Psychological Apparatus: A History of Experimental Psychology Through the Reconstruction of Peirce and Jastrow’s ‘On Small Differences of Sensation’ (1885).” Nuncius 38 (3): 553–582. doi:10.1163/18253911-bja10066.

  • This study demonstrated the importance of performing experimental replication as an underutilized method for history and philosophy of psychology and psychometrics. We empirically performed and uncovered the underlying methodology of an 1884 psychophysics experiment, debunking its traditional interpretation as a predecessor for randomised controlled trials.

Measurement Heresy

I run Measurement Heretics: A Reading Group in Human(e) Sciences through the Measurement Lab in the Discovery Research Platform for Medical Humanities since 2025. Jumping off from the Measurement Heretics Workshop that I organized in March 2026, I am in the process of editing a volume called The New Measurement Heretics with Michele Luchetti, Morgan Thompson, and Aja Watkins. Our call for chapters is now closed, but do get in touch if you would like to be involved in future group outputs.

Feel free to play with our Wall of 95 Measurement Theses (Maximilian Hepach created this digital version of our workshop discussion wall), and take our buzzfeed-style quiz Are You a Measurement Heretic? to find out how your beliefs about measurement rank, from heresy to dogmatism.

Clinical Measurement

Clinimetrics or Clinical Psychometrics? Reexamining Disciplinary Boundaries and Measuring Methodologies

FoUU X-Talks, Region Uppsala, Sweden Rebecca Jackson and Mikael Andersén, 29 April 2024.

Measuring Healthcare Provider Work

• Tilden, Ellen, Steve Calvin, and Rebecca L. Jackson. “Antenatal Outpatient Relative Value Units: A Historical Analysis of Undervaluation,” under review at Birth: Issues in Perinatal Care.
• We connect the history of prenatal appointments in the 20th century, shaped by insurance and Medicaid reimbursement structures, to investigate the medical evidence (or lack thereof) which led to the current time standards that dictate the duration of face-to-face care pregnant people receive in the US. We show that “relative value units” (RVUs) and bundled reimbursement models have inadvertently placed constraints on care, which in turn shapes the kind of observational evidence we can produce about what impact that appointment duration has for pregnant people in already underserved populations.

Dissertation

Measuring “Well”: Clinical Measuring Practices and Philosophy of Measurement

This dissertation examines four successful, patient-centric measuring practices in the Anglo-American clinical context, spanning from the early 19th century to today: (1) the use of “drops” as a fluid unit in medicine and pharmacy (2) the measurement of cervical dilation by hand (digital cervimetry) for labor assessment (3) the APGAR score for newborn health assessment, and (4) the current development of the Patient Generated Index for measuring patient status and outcomes. All four practices were developed to ensure preferable patient outcomes, at the expense of precisely representing empirical states. I discuss the ethical and epistemic challenges past practitioners had to overcome when validating these measures, how they went about it, and consider how their endeavors can inform methodological issues faced in the formation of clinical indexes today. The ethical-epistemic challenge of having both “patient-centric” and “evidence-based” measurement has a much longer history than the recent emergence of such terms suggests.