{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T20:53:42Z","timestamp":1770411222641,"version":"3.49.0"},"reference-count":25,"publisher":"Proceedings of the National Academy of Sciences","issue":"33","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2009,8,18]]},"abstract":"<jats:p>Although no historical information exists about the Indus civilization (flourished<jats:italic>ca<\/jats:italic>. 2600\u20131900 B.C.), archaeologists have uncovered about 3,800 short samples of a script that was used throughout the civilization. The script remains undeciphered, despite a large number of attempts and claimed decipherments over the past 80 years. Here, we propose the use of probabilistic models to analyze the structure of the Indus script. The goal is to reveal, through probabilistic analysis, syntactic patterns that could point the way to eventual decipherment. We illustrate the approach using a simple Markov chain model to capture sequential dependencies between signs in the Indus script. The trained model allows new sample texts to be generated, revealing recurring patterns of signs that could potentially form functional subunits of a possible underlying language. The model also provides a quantitative way of testing whether a particular string belongs to the putative language as captured by the Markov model. Application of this test to Indus seals found in Mesopotamia and other sites in West Asia reveals that the script may have been used to express different content in these regions. Finally, we show how missing, ambiguous, or unreadable signs on damaged objects can be filled in with most likely predictions from the model. Taken together, our results indicate that the Indus script exhibits rich synactic structure and the ability to represent diverse content. both of which are suggestive of a linguistic writing system rather than a nonlinguistic symbol system.<\/jats:p>","DOI":"10.1073\/pnas.0906237106","type":"journal-article","created":{"date-parts":[[2009,8,6]],"date-time":"2009-08-06T01:45:25Z","timestamp":1249523125000},"page":"13685-13690","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":27,"title":["A Markov model of the Indus script"],"prefix":"10.1073","volume":"106","author":[{"given":"Rajesh P. N.","family":"Rao","sequence":"first","affiliation":[{"name":"Department of Computer Science and Engineering, University of Washington, Seattle, WA 98195;"}]},{"given":"Nisha","family":"Yadav","sequence":"additional","affiliation":[{"name":"Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005, India;"},{"name":"Centre for Excellence in Basic Sciences, Mumbai 400098, India;"}]},{"given":"Mayank N.","family":"Vahia","sequence":"additional","affiliation":[{"name":"Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005, India;"},{"name":"Centre for Excellence in Basic Sciences, Mumbai 400098, India;"}]},{"given":"Hrishikesh","family":"Joglekar","sequence":"additional","affiliation":[{"name":"14, Dhus Wadi, Laxminiketan, Thakurdwar, Mumbai 400002, India;"}]},{"given":"R.","family":"Adhikari","sequence":"additional","affiliation":[{"name":"Institute of Mathematical Sciences, Chennai 600113, India; and"}]},{"given":"Iravatham","family":"Mahadevan","sequence":"additional","affiliation":[{"name":"Indus Research Centre, Roja Muthiah Research Library, Chennai 600113, India"}]}],"member":"341","published-online":{"date-parts":[[2009,8,18]]},"reference":[{"key":"e_1_3_3_1_2","volume-title":"Archaeological Survey of India Report for the Year 1872-73","author":"Cunningham A","year":"1875","unstructured":"A Cunningham Archaeological Survey of India Report for the Year 1872-73 (Archaeological Survey of India, Calcutta, India, 1875)."},{"key":"e_1_3_3_2_2","volume-title":"Ancient Cities of the Indus Valley Civilisation","author":"Kenoyer JM","year":"1998","unstructured":"JM Kenoyer Ancient Cities of the Indus Valley Civilisation (Oxford Univ Press, Oxford, UK, 1998)."},{"key":"e_1_3_3_3_2","volume-title":"The Indus Civilisation","author":"Possehl GL","year":"2002","unstructured":"GL Possehl The Indus Civilisation (Alta Mira Press, Walnut Creek, CA, 2002)."},{"key":"e_1_3_3_4_2","volume-title":"The Indus Age: The Writing System","author":"Possehl GL","year":"1996","unstructured":"GL Possehl The Indus Age: The Writing System (University of Pennsylvania Press, Philadelphia, 1996)."},{"key":"e_1_3_3_5_2","volume-title":"Pattern Recognition and Machine Learning","author":"Bishop C","year":"2008","unstructured":"C Bishop Pattern Recognition and Machine Learning (Springer, Berlin, 2008)."},{"key":"e_1_3_3_6_2","first-page":"140","article-title":"Graphical models","volume":"19","author":"Jordan MI","year":"2004","unstructured":"MI Jordan, Graphical models. Stat Sci (Special Issue on Bayesian Statistics) 19, 140\u2013155 (2004).","journal-title":"Stat Sci (Special Issue on Bayesian Statistics)"},{"key":"e_1_3_3_7_2","first-page":"135","article-title":"Extension of the law of large numbers to dependent quantities (in Russian)","volume":"15","author":"Markov AA","year":"1906","unstructured":"AA Markov, Extension of the law of large numbers to dependent quantities (in Russian). Izv Fiz-Matem Obsch Kazan Univ (2nd Ser) 15, 135\u2013156 (1906).","journal-title":"Izv Fiz-Matem Obsch Kazan Univ (2nd Ser)"},{"key":"e_1_3_3_8_2","volume-title":"Statistical Methods for Speech Recognition","author":"Jelenik F","year":"1997","unstructured":"F Jelenik Statistical Methods for Speech Recognition (MIT Press, Cambridge, MA, 1997)."},{"key":"e_1_3_3_9_2","volume-title":"Foundations of Statistical Natural Language Processing","author":"Manning C","year":"1999","unstructured":"C Manning, H Sch\u00fctze Foundations of Statistical Natural Language Processing (MIT Press, Cambridge, MA, 1999)."},{"key":"e_1_3_3_10_2","unstructured":"N Yadav et al. Statistical analysis of the Indus script using n-grams arxiv: 0901.3017 (available at http:\/\/arxiv.org\/abs\/0901.3017). 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International Journal of Dravidian Linguistics 37, 39\u201352 (2008).","journal-title":"International Journal of Dravidian Linguistics"},{"key":"e_1_3_3_16_2","first-page":"53","article-title":"Segmentation of Indus texts","volume":"37","author":"Yadav N","year":"2008","unstructured":"N Yadav, MN Vahia, I Mahadevan, H Joglekar, Segmentation of Indus texts. International Journal of Dravidian Linguistics 37, 53\u201372 (2008).","journal-title":"International Journal of Dravidian Linguistics"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1170391"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1006\/jtbi.1997.0493"},{"key":"e_1_3_3_19_2","first-page":"19","article-title":"The collapse of the Indus-script thesis: The myth of a literate Harappan civilization","volume":"11","author":"Farmer S","year":"2004","unstructured":"S Farmer, R Sproat, M Witzel, The collapse of the Indus-script thesis: The myth of a literate Harappan civilization. Electronic Journal of Vedic Studies 11, 19 (2004).","journal-title":"Electronic Journal of Vedic Studies"},{"key":"e_1_3_3_20_2","first-page":"125","article-title":"Syntactic methods in the study of the Indus script","volume":"50","author":"Koskenniemi K","year":"1981","unstructured":"K Koskenniemi, Syntactic methods in the study of the Indus script. Studia Orientalia 50, 125\u2013136 (1981).","journal-title":"Studia Orientalia"},{"key":"e_1_3_3_21_2","first-page":"111","volume-title":"Airavati: Felicitation Volume in Honor of Iravatham Mahadevan","author":"Parpola A","year":"2008","unstructured":"A Parpola Airavati: Felicitation Volume in Honor of Iravatham Mahadevan (Chennai, India), pp. 111\u2013131, www.varalaaru.com. (2008)."},{"key":"e_1_3_3_22_2","volume-title":"PhD dissertation","author":"Wells BK","year":"2009","unstructured":"BK Wells PhD dissertation (Harvard University, Cambridge, MA, 2009)."},{"key":"e_1_3_3_23_2","article-title":"An emperical study of smoothing techniques for language modeling","author":"Chen SF","year":"1995","unstructured":"SF Chen, J Goodman, An emperical study of smoothing techniques for language modeling. Harvard University Computer Sci, Technical Report TR-10-98. (1995).","journal-title":"Harvard University Computer Sci"},{"key":"e_1_3_3_24_2","doi-asserted-by":"crossref","unstructured":"R Kneser H Ney vol 1 181\u2013184 (1995).","DOI":"10.1109\/ICASSP.1995.479394"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1109\/TIT.1967.1054010"}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.0906237106","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,2,11]],"date-time":"2025-02-11T17:33:21Z","timestamp":1739295201000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.0906237106"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,8,18]]},"references-count":25,"journal-issue":{"issue":"33","published-print":{"date-parts":[[2009,8,18]]}},"alternative-id":["10.1073\/pnas.0906237106"],"URL":"https:\/\/doi.org\/10.1073\/pnas.0906237106","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,8,18]]},"assertion":[{"value":"2008-12-26","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2009-08-18","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}