Stage 4 – Does this phase of reading extend beyond a single sentence?

single sentence?

Stage four considers whether each fixation within a phase of reading has remained within a single sentence or crossed sentence boundaries into a new sentence and is illustrated in Figure 19.

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Khalifa and Weir (2009:59) distinguish between careful reading at sentence level (local reading) which focuses on understanding the sentence proposition in isolation from the rest of the ideas in the text. Khalifa and Weir suggest that once reading extends beyond sentence boundaries (global reading) readers become engaged in ‘integrating new information into a mental model and perhaps finally creating a discourse level structure for the text’ (Khalifa and Weir, 2009:59).

The stage four process for assigning a local or global considers the AOI of each fixation and checks whether this fixation and the preceding fixation occurred in the same sentence. The first stage is to check for an AOI (sentence indicator). If the AOI is blank, the fixation was not on the written source text and the global /local score is reset to zero and the global / local classification is left blank.

If there is an AOI for this fixation, the next stage is to check if the previous AOI was blank. If the previous fixation’s AOI was blank, then this fixation must necessarily be the first fixation in an episode and one is added to the global/local score (The global /local score is used later to determine whether to apply a global / local label).

If the last fixation AOI was not blank, the AOI of this fixation and the previous fixation are compared. If the AOIs are the same, then one is added to the global / local score. If there has been a change of AOI, 5000 is added to the global / local score.

Now that all the possible combinations have been scored, the global / local score is tested. If the global / local score is less than 5000, a label of local is applied. If the global / local score is 5000 or more a global classification is applied.

It is necessary to use a scoring system rather than simply comparing the current fixation to the previous fixation because otherwise, as soon as two successive fixations occurred in the same sentence, the global/local label would return to local. By using this

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system of scoring each fixation, every fixation in the current episode of reading is taken into consideration and once the episode leaves the sentence in which the episode of reading started, the global label will be applied and maintained. The only disadvantage of this system is that if 5000 successive fixations in an episode stayed within the same sentence the algorithm would falsely apply a global label. However, this is extremely unlikely, given that most participants only generated about 7000 fixations in total.

The global and local classifications, when applied to fixations that are marked as Careful reading, correspond to Khalifa and Weir’s 2009 classification for Careful global reading and Careful local reading. However, the global and local classifications when applied to reading classified as ‘selective’ do not correspond directly to Khalifa and Weir’s Expeditious global reading and Expeditious local reading. The reasons for this, and the disparities between the classifications, are discussed further in section 5.2.2.2of the discussion chapter.

After processing through stages one to 4, each fixation has been given a reading classification (indicated in the red output parallelograms in Figure 18) and every instance of reading has been marked as local or global (indicated by the blue output parallelograms in Figure 19).

This results in every fixation on the written source texts being allocated to one of four types of reading as follows:

1. Careful local reading which has a ratio of at least three short forward moving fixations for every regressive fixation. This category will not tolerate any long forward jumps or any long regressions to the previous sentence.

2. Careful global reading therefore, still requires the ratio of three short forward to every regression but will allow the reader to progress to the next sentence but only by means of a short forward or a return sweep. Long regressions which jump back to an earlier part

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of the text would be permitted as long as the regression rate remains within permitted limits. A long glance back to an earlier part of the text to resolve confusion could be part of careful global reading. However, if the reader then used a long jump forward through the text to return to the previous section of text this would prompt a reset, therefore a minimum of three short forward moving fixations would need to occur to return the reading classification to careful again.

3. Selective local reading occurs when an episode of reading does not meet the ratio of at least three short moving fixations to every regression but stays within a single sentence. For example, there may be a very high amount of regressions or there may be long forward saccades but within a single sentence.

4. Selective Global reading occurs when an episode does not meet the requirements for careful reading and extends beyond a single sentence. For example, the forward / regression ratio for careful reading is not met, or the episode includes long forward moving fixations and the episode crossed from one sentence into another.