Orthographic Mapping & Sight Word Development

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Let’s begin this discussion with a technical definition of a sight word. A sight word is any word that you can automatically and accurately recognise and associate with the correct pronunciation and meaning. It is not a word that must be memorised as a whole word nor is it referring exclusively to frequently used words nor words containing unusual or irregular spellings. As a skilled reader, you have stored in long-term memory hundreds of sight words that you can immediately recall. Having a large sight word vocabulary is an important component of comprehension as it enables the reader to focus on making sense of the text rather than on the decoding process.

Ehri (2024) provides a comprehensive discussion of the role orthographic mapping plays in sight word development. Below is an overview of some of the key concepts outlined in the article:

Orthographic Mapping

  • Orthographic consists of ‘ortho’ means ‘correct’ and ‘graph’ means ‘to write’ (i.e., the correct writing/spelling of words).
  • Orthographic mapping is the process of systematically forming connections between letter(s) (graphemes) and the corresponding pronunciation based on the reader’s knowledge of how the spoken language is represented.
  • To form sight words in memory requires the brain to connect the correct sequence of a string of letters to its corresponding pronunciation.
  • Spelling words correctly is significantly more difficult than reading words as spelling requires recall which is much more difficult than recognition, which is the skill required for reading. The difficulty of spelling words correctly in English is compounded by the multiple plausible alternative spellings of the sounds in the word.

Knowledge & Skills Needed for Orthographic Mapping

  • Beginning readers need to be systematically taught the following skills:
    • Segmenting words into individual phonemes (sounds).
    • Learning mouth positions and movements associated with the formation of different phonemes and linking these to the formation of words.
    • Learning graphemes and linking this to the phoneme(s) and linking these to the formation of words (i.e., blending).
  • Next students need to be taught to represent the phonemes in words to graphemes – these grapheme-phoneme correspondences are the glue in orthographic mapping that binds spellings to pronunciation resulting in the automatic spelling and reading of words.
  • Decoding involves reading unfamiliar words by transforming letters into sounds and blending these to form a word. This is different to orthographic mapping which is the process of binding the spelling of words to their pronunciation and storing in long-term memory so readers no longer need to decode the word.
  • Orthographic mapping can be activated by decoding and encoding words.

Orthographic Mapping: From Grapheme-Phoneme Units to Multi-Letter units

  • Initially, students may only partially map graphemes and phonemes due to poor phoneme awareness and/or poor grapheme knowledge.
  • Orthographic mapping is also effective for storing the spelling of irregularly spelled words and this mapping should be explicitly taught (e.g., in ‘said’ – the ‘ai’ needs to be mapped to the sound /e/).
  • As readers become more competent, they begin to map common multi-letter units such as morphemes (prefixes, suffixes, root words) and syllables (fan-tas-tic).
  • The extent of (and consequently gaps in) orthographic mapping is revealed in the types of errors made when reading and spelling.

Forming Semantic (Meaning) Connections

  • Forming grapho-semantic connections is not a mapping process.
  • The process is associative and occurs due to a knowledge of spoken words or by inferring the meaning of words from the text in which it occurs.
  • The meaning of spoken words become connected to their written form once the written form has become activated and bonded in memory.

The underlying message is that orthographic mapping is an important component of fluent reading and underpinning this process is phonemic awareness (in particular blending and segmenting), a knowledge of the alphabetic writing system, decoding skills and encoding skills. Linked to this is connecting meaning to orthographically mapped words.


Ehri, L.C., (2024). Clarifying the role of orthographic mapping in sight word reading, The Reading League Journal, 5 (1), 4-13.