Missing letter effect
[1][2] Understanding how, why and where this effect arises becomes useful in explaining the range of cognitive processes that are associated with reading text.
The method in which researchers utilise to measure this effect is termed a letter detection task.
This involves a paper-and-pencil procedure, where readers are asked to circle a target letter, such as "t" every time they come across it while reading a prose passage or text.
Age (development), language proficiency and the position of target letters in words are some of these factors.
Participants of this task are given prose passages or continuous texts to read and are told to circle every occurrence of a target letter.
Two primary hypotheses tried to explain the missing letter effect: Healy (1994) emphasized identification processes playing a crucial role, almost entirely focusing on word frequency.
[11] This hypothesis is primarily referred to as the unitization model[12] and relates to familiar visual configuration.
[4] In this model, once readers have finished processing the text at a higher level (units like words), they move on and continue reading a different section of text, which interferes with the completion of processing of lower-level units (like letters).
[4] The result is more letter detection errors occurring from insufficient processing of the lower-level units.
[2][4] The processing time hypothesis also proposed by Healy,[2] provides an explanation for the missing letter effect.
It is a combination of the two models proposed by Healy, Koriat, and Greenberg and illuminates the idea that word frequency and function together influence the rate of letter detection errors and omissions.
[15] The organisation of sentence structure proceeds to “guide attention” to the higher-level units and less frequent content words to understanding meaning.
[18] Developmental change, grade level and generally reading skills increase with age, and all of these factors have some influence on the missing letter effect.
[16][19] When testing primary and elementary school children from grades one to four, the missing letter effect is higher for children who have better reading skills, where they tend to make more letter detection errors on function words than in rare content words.
[19] Because the configuration of texts and words influence the missing letter effect and letter detection errors, younger readers who have not yet developed enough to be conscious of text structure, are not affected as greatly as older readers by structural function words when analysing passages.
[10][16] The hypotheses assume and depict that more developed, good readers, whom of which are generally older, display more responsiveness to word frequency, in that they omit more target letters to more frequent words than younger, less developed poor readers.
