Historical glottometry

Key takeaways

Historical glottometry belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Historical glottometry to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Historical glottometry from memory before moving on to harder problems.

Reference excerpt

Historical glottometry is a method used in historical linguistics. It is a quantitative, non-cladistic approach to language subgrouping. The aim of historical glottometry (HG) is to address the limitations of the tree model when applied to dialect continua and linkages. It acknowledges that the genealogical structure of a linkage typically consists of entangled subgroups, and provides ways to reconstruct that internal structure by measuring the relative strength of these subgroups. This approach was developed by Alexandre François (CNRS) and Siva Kalyan (ANU). While the method was initially applied to Oceanic languages, in recent years it has been applied to a much broader range of language families.

Rationale Historical Glottometry grew out of the observation that a large number of language families in the world form linkages (a term coined by Malcolm Ross), i.e. they evolved out of former dialect continua in which historical innovations tend to overlap. Such linkages do not conform with the Tree model often used in historical linguistics, which presupposes that innovations should be nested. This common situation is better approached using the Wave model. Inspired by dialectometry, the aim of Historical Glottometry is to provide an alternative, non-cladistic approach to language genealogy, while remaining true to the principles of the Comparative method developed by Neogrammarians in the 19th century.

Principles of the method The fundamental principles of Historical Glottometry include the following:

each subgroup is defined by exclusively shared innovations (a principle first expressed by Leskien [1876]), i.e. linguistic synapomorphies; subgroups are allowed to intersect (as expected under the Wave model); the “strength” of each subgroup is measured on a continuous scale (rather than subgroups simply being absent or present). That strength is assessed using two ratings, named cohesiveness and subgroupiness.

Glottometric diagrams One of the outputs of Historical Glottometry takes the form of a “glottometric diagram”. Such diagrams are analogous to the isogloss maps used in dialectology, except that each isogloss refers not to a single innovation but to a set of languages defined by one or more exclusively-shared innovations — that is, a genealogical subgroup. The glottometric diagram represents graphically the strength of each subgroup. Thus, the contour's thickness can be made proportional to the rate of “cohesiveness” or “subgroupiness” calculated for that subgroup. The homepage of Historical Glottometry includes an example of a glottometric diagram, based on a study of the Torres–Banks linkage in Vanuatu. Glottometric results can also be displayed in the form of Neighbornets, or of glottometric maps.

Applications to particular language families Several studies have been conducted, partly or entirely within the framework of Historical glottometry – including the following:

on the Torres–Banks linkage, a group of Oceanic languages from Vanuatu (François 2014, 2017; Kalyan & François 2018); on Sogeram languages, a subgroup of the Madang family from Papua New Guinea (Daniels et al. 2019); on the dialects of Boni, a subgroup of Cushitic languages from Kenya and Somalia (Elias 2019); on Arabic dialects of Egypt and Sudan (Leddy-Cecere 2021); on Numic languages, a subgroup of Uto-Aztecan languages from North America (Rannap 2017); on Enlhet–Enenlhet languages, a group of languages spoken in Paraguay (van Gysel 2017); on early Germanic languages (Agee 2018); on the dialects of Old English (Den Hertog 2024).

Historical glottometry and incomplete lineage sorting Jacques & List (2019) show that the concept of incomplete lineage sorting can be applied to account for non-treelike phenomena in language evolution. Kalyan and François (2019) concur that "Historical Glottometry does not challenge the family tree model once incomplete lineage sorting has been taken into account" – provided the internal variation discussed in the analysis includes the geographical (dialectal) dimension.

See also Comparative method Dialectology Dialectometry Genetic relationship (linguistics) Linkage (linguistics) Wave model

External links Homepage of Historical glottometry, including a tutorial and a bibliography. Historical glottometry online analyzer, a free tool allowing users to upload their own historical data, perform glottometric calculations, and generate a glottometric map.

Notes

References Main references François, Alexandre (2014), "Trees, Waves and Linkages: Models of Language Diversification", in Bowern, Claire; Evans, Bethwyn (eds.), The Routledge Handbook of Historical Linguistics, London: Routledge, pp. 161–189, ISBN 978-0-41552-789-7. Kalyan, Siva; François, Alexandre (2018), "Freeing the Comparative Method from the tree model: A framework for Historical Glottometry" (PDF), in Kikusawa, Ritsuko; Reid, Laurie (eds.), Let's talk about trees: Tackling Problems in Representing Phylogenic Relationships among Languages, Senri Ethnological Studies, 98, Ōsaka: National Museum of Ethnology, pp. 59–89. Other references

Worked examples

Example 1 — a first encounter with Historical glottometry

Start with the simplest possible case. Write down what Historical glottometry claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Historical glottometry before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Historical glottometry ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Historical glottometry

In research: Historical glottometry appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Historical glottometry in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Historical glottometry is common in secondary-school and first-year university syllabi. It links to neighbouring topics Comparative linguistics, Historical linguistics, Quantitative linguistics, so understanding it makes those chapters shorter.
In everyday life: Look for Historical glottometry outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Historical glottometry in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Historical glottometry means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Historical glottometry out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Historical glottometry in simple terms?

Historical glottometry is a method used in historical linguistics. It is a quantitative, non-cladistic approach to language subgrouping.

Why does Historical glottometry matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Historical glottometry?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Historical glottometry.