**4. Methodology**

*Visual Impairment and Blindness - What We Know and What We Have to Know*

durations are indicative of the amount of processing which is occurring, with longer fixations on words that require more processing [17]. Words which require more processing are infrequent words, while longer fixations are seen when making inferences at the end of a sentence and when integrating information from important clauses [17]. As a means to detect mindless wandering, or low attention while reading, eye movement behaviour at the end of phrases or sentences can be used—the natural slowing down in reading which occurs in order to integrate the words does not occur when attention is low [41]. Additionally, the variability in fixation durations caused by word length and frequency is lower when the reader is not paying attention [41]. Hence, when the mind of the reader wanders, there are short fixations on low frequency words and long fixations on high frequency words [41]. Fixations are also fewer and longer and eye behaviour is more erratic when the mind wanders [42]. First fixation durations, total gaze duration and total viewing time are shorter for normal reading than for wandering [42]. Additionally, when the mind wanders, readers are less likely to make fixations and regressions on text and more likely to fixate on areas other than the text [42]. The number of saccades and fixations drops when the mind wanders and there are less and shorter within-word

When scanning transformed text as opposed to reading, fixations are longer and saccades are shorter [15]. In this instance, transformed text refers to the practice of replacing all alphabetic characters with the letter z but preserving casing and punctuation among other characteristics [15]. Participants were requested to pretend to read the transformed text [15] in order to simulate scanning. In contrast, skimming normal text for proofreading is characterised by shorter fixations, and longer saccades than when reading text for understanding [21]. Readers also tend to read the start of the text more thoroughly than the second half and readers first skim the entire text before reading it [28]. When reading in a second language (L2), reading times are longer and readers exhibit more fixations, shorter saccades and less word skipping than when they read in their first language (L1) [44]. Furthermore, L2 readers of Afrikaans text required an average of one fixation per syllable [45]. Fixation durations for L2 readers were longer, averaging 313 and 331 ms for an easy and difficult text respectively [45]. The increased fixation times in L2 could be attributed to the fact that L2 processing requires more cognitive load than L1 [32]. One of the purposes of this research is to understand whether the reading ability of South African township learners can meaningfully be classified using the guidelines

In a comprehensive study eye movement behaviour was investigated for the different types of reading. This study will be discussed in greater depth for the purposes of this chapter. Regular reading, or reading for comprehension, is defined as reading a piece of text as one would normally read [46] as cited [47]. Thorough reading is reading to learn and is used to read text in a manner which will allow them to learn the content, perhaps in order to write a test about the content [48] as cited in [47]. Skimming, also known as reading for gist, means the reader must read the text as quickly as possible while still trying to understand the content [46] as cited in [47] and spell checking is the type of reading which is conducted in order to detect spelling errors in a text [49].

Thorough reading exhibits longer reading times and more rereading which results in higher comprehension scores [47]. When skimming, participants exhibit longer saccades, short fixations and skip more words [47]. Additionally, the total reading time is shorter and comprehension is lower [47]. When reading in order to achieve spell checking, saccades are short, fixation durations are long and fewer words are skipped [47]. Comprehension scores are lower and total reading times are longer [47]. Overall thorough reading was less uniform than regular reading, skimming was faster and more uniform and spell checking was slower and more uniform [47].

developed in publications such as those referred to above.

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regressions [43].
