Home | Biodata | Biography | Photo Gallery | Publications | Tributes




"Kolam is a traditional Indian folk art widely used to decorate the thresholds and courtyards in front of houses. In South Indian villages, the courtyard in front of each house is decorated every morning by drawing traditional designs called kolam. The decoration of the floor with kolam designs is carried out by young women who deftly draw with pinches of flour held between the thumb and the first finger and letting the powder fall in a continuous line by moving the hand in desired directions. On festive occasions, the kolam designs are more elaborate and complicated. Although kolam (termed Rangoli in north of India) is practised in most parts of India, the geometric patterns that constitute the kolam and manner of constructing them vary from region to region. A kolam could be made up of a single, unsegmented, closed thread of line or it could be made up of superimposition of two or more closed threads of lines, each constituting one component of the global kolam pattern.Kolam drawing is practised extensively in South India by women of all ages. Children, mostly girls, learn the art of drawing kolam patterns from childhood and could acquire an astonishingly large repertoire of designs, which they can draw readily from memory." [1] 

"Gift Siromoney of Madras Christian College initiated the use of kolam patterns in the study of picture languages. For Gift Siromoney, working with his wife Rani Siromoney and other computer scientists, like Kamala Krithivasan and K. G. Subramanian, the kolam patterns became a rich source of figures that could be used as examples of existing types of picture languages and also served as a stimulus for creation of new types of languages. Gift Siromoney carried out a variety of interesting studies on kolam patterns both in the field and in the laboratory about its history, about its diffusion from one region to the another, about the manner of learning and memorizing the individual patterns and their reproduction. The commemorative volume for Gift Siromoney includes a bibliography that lists about 100 publications of his, a body of work that shows the many ways in which he, throughout his life, combined his academic interests with deep concern for environment, history and culture of Tamil Nadu." [2]

"Concerning the history of kolam, Gift Siromoney has pointed out that the earliest references to kolam drawing in Tamil literary works occur in Madurai Meenakshiammai Kuram (16th Century), and, later, in Thiru Kutraala Kuravanji (17th Century). These references include a description of  the manner of preparation of the surface before constructing the kolam patterns. Siromoney notes that "there is no reference to kolam in Tamil word-lists called Nigandus, in earlier Tamil literature, in ancient paintings, or in travellers' accounts.

The formal mathematical properties of kolam parrerns have been investigated in pioneering studies by Siromoney and his colleagues at the Madras Christian College (MCC). Formal language theory has been successfully applied to the study of these folk art patterns. Classes of kolam patterns (1 , 2) can be considered as sentences of 2-dimensional picture languages with formally definable syntactic rules. Making use of the underlying syntax rules, computer programs for mechanical generation of kolam patterns belonging to particular languages had also been devised.

A complex kolam pattern forms a 'figure' over a 'ground' made up of a grid of dots. These dots called pul@l@is in Tamil clearly serve as props or aids facilitating the learning as well as the reproduction process.  Learning, memorizing and reproducing are easier for kolam patterns that can be parsed readily, i.e., that can be decomposed into their constituent units. That pul@l@i in practice act as aids by forming a skeletal framework for kolam practitioners, and that skilled kolam practitioners, in fact, remember the patterns in terms of their parsed constituent units, was demonstrated by Gift Siromoney in a series of elegant experiments. A prerequisite to such a demonstration is our ability to take snapshots of stages in the reproduction process as the kolam practitioner draws a given kolam pattern. Siromoney devised an ingenious, but simple and inexpensive technique to accomplish this.

Siromoney's snapshot technique works as follows. Stack, say, 7 sheets of paper and interleave them with black carbon paper. Use a red ballpoint pen for drawing the kolam pattern. The subject starts the kolam drawing on the top sheet. At the end of the first stage (or, after a predetermined time interval), remove the top sheet and the carbon underneath it. The subject continues to draw the kolam pattern on the second sheet which is now the top sheet. At the end of the second stage, the current top sheet together with its carbon is removed. This process is continued through all the seven stages. Clearly, each sheet (after the completion of the kolam drawing) will contain all parts drawn during the previous stages in black (due to carbon papers) and the part added in the current stage in red.

In a series of experiments, skilled kolam practitioners were tested by Siromoney by asking them to draw pre-identified kolam patterns from memory. Their drawing strategies were recorded using the snapshot technique described above. It was found that the practitioners invariably drew the pul@l@is first to define the grid. The kolam patterns were constructed over the grid stage by stage in a manner conforming to the natural segment ability of the pattern.

In other experiments, Siromoney was able to show that the kolam practitioners and na´ve individuals (not familiar with such patterns) differ in their capacity to copy (unfamiliar) kolam patterns. They also differ in their capacity to discriminate between similar and different kolam patterns on brief exposure. Expertise in kolam drawing is, thus of the nature of a skill and exhibits all the attributes that psychologists associate with skill-acquisition and performance. Although the performance of this skill results in products (i.e., kolam patterns) that possess complex grammatical properties, the practitioners of the skill are themselves unaware of this fact since a large proportion of the practitioners are nonliterate." [1}

Gift Siromoney was always interested in knowing how the womenfolk remember the complicated kolam patterns. In the month of Margazhi early in the morning he would set out on his motorbike to observe women in action he was intrigued by the remarkable ease with which women drew these patterns. He conducted experimental studies and found to his great interest that they draw it in almost the same way as done by using turtle moves such as go forward, turn left, make a loop and so on. He extended it to kolam moves to capture non-angular kolam patterns.

One other question he was generally interested in was (i) "whether a given kolam pattern is made up of a single strand (single kambi) or multiple strands (multi kambi)" (ii) "whether it is easier to memorize and remember a single kambi or multi kambi". In the working paper , he introduced two operations, 'cut and join', 'cut and connect'. Using these he showed how a single kambi kolam could be transformed into multi kambi kolam or vice versa. The same operations are noted in  Circular DNA Splicing Theory as well. [3]

-T. Robinson. Department of Mathematics, MCC.


[1] R. Narasimhan, The oral-literate dimension in Indian culture, Indological Essays, Commemorative Volume II for Gift Siromoney, ed. Michael Lockwood, Madras Christian College,1992, pp. 67-79.
[2] Marcia Ascher, The kolam Tradition, American Scientist, Vol.90, January-February 2002, pp.56-61. [3]Rani Siromoney, K.G.Subramanian, V.R.Dare, Circular DNA and Splicing Systems, Proc.of ICPIA, Lecture Notes in Computer Science, 654, Springer-Verlag, 1992, pp 260-273.


  1. Abstract families of matrices and picture languages
    Computer Graphics and Image Processing, i (1972), 284-307 (with Rani Siromoney and Kamala Krithivasan)  
  2. Picture languages with array rewriting rules
    Information and Control, xxii (1973), 447-470 (with Rani Siromoney and Kamala Krithivasan)  
  3. Array grammars and kolam
    Computer Graphics and Image Processing, iii (1974), 63-88 (with Rani Siromoney and Kamala Krithivasan)  
  4. Mathematics for the Social Sciences
    National Book Trust, India, New Delhi, 1976 (with Rani Siromoney)  
  5. South Indian kolam patterns
    Kalakshetra Quarterly, 1, No. 1, 1978, pp. 9-14  READ
  6. On understanding certain kolam designs
    Paper presented at the Second International Conference on Advances in Pattern Recognition and Digital Techniques, January 6-9, 1986 at the Indian Statistical Institute, Calcutta. (with Chandrasekaran, R.)  READ
  7. Studies in the Traditional art of kolam
    Working paper I, May 1985.(Manuscript)  
  8. Perception of structure and complexity in South Indian kolam patterns
    STAT- 62/ 86, March 1986.  
  9. Rosenfeld 's cycle grammars and kolam
    TR Math 20/87 July 1987, presented at the Third International Workshop on Graph Grammars and their applications to Computer Science, Airlie, Virginia, December 2-6, 1986,
    also in, Graph  grammars and their application to Computer Science, Lecture Notes in Computer Science, 291, 1987, 564-578, Springer-Verlag (with Rani Siromoney)  
  10. Kambi kolam and cycle grammars
    "A Perspective in Theoretical Computer Science, Commemorative Volume for Gift Siromoney" (Series in Computer Science 16) ed. R. Narasimhan, World Scientific Publishing Co., Singapore, June 1989, 267-300 (with Rani Siromoney and Robinson. T.)  
Go to the top of the page

Home | Biodata | Biography | Photo Gallery | Publications | Tributes