**5.1 Qualitative discussion**

The images below are gaze plots and serve to qualitatively illustrate the different reading behaviours which were evident in the sample.

**Figure 1** is a gaze plot of the strongest reader in the group. From this it can clearly be seen that the reader fixated on most words. Durations, as reflected by the size of the fixation points, fluctuate within acceptable ranges. Some fixations are slightly offset but it can clearly be seen that reading is occurring at a steady pace with regular reading behaviour.

**Figure 2** is an example of one of the jumping barkers who is clearly not reading but rather exhibiting clusters of fixations interspersed with large saccades—or

**Figure 1.**

*The gaze plot of the strongest of the learners in the 'moderate reader' category.*

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*\**

**Table 3.**

**Figure 3.**

Poor readers

Moderate readers

Kruskal-Wallis

Expected values

*Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

iour very closely mimics proper reading.

**5.2 Reading metrics for whole text**

*The gaze plot of one of the 'regular barkers'.*

Barkers\* <sup>23</sup> *<sup>x</sup>*¯ = 88.9

**N Reading speed (ms per character)**

<sup>25</sup> *<sup>x</sup>*¯ = 85.7

<sup>19</sup> *<sup>x</sup>*¯ = 88.1

sd = 29.1

sd = 19.6

sd = 33.1

Thorough reading 56 ms/c Skimming 26 ms/c Spell checking 62 ms/c Regular reading 45 ms/c

*Barkers includes jumping and regular barkers due to the nature of these metrics.*

*A summary of the analysis for the metrics calculated over the whole piece of text for all participants.*

constant for this jumper.

jumps. Fixations are more erratic and spread wildly over the body of the text and no regular pattern is discernible except in short spurts hence they are not habitual barkers but instead tend to skip large parts of the text. Durations also remain fairly

**Figure 3** is one of the regular barkers, but here it can be seen that the fixations closely relate to regular reading. There is a regular pattern, fixations are spread over the whole text and on each word the durations fluctuate. This type of pattern is representative of the majority of the barkers and it can be deduced that the behav-

This section discusses the metrics which were analysed for the whole text while

**Mean fixation duration (ms)**

> *<sup>x</sup>*¯ = 296.8 sd = 63.2

*<sup>x</sup>*¯ = 310.9 sd = 42.8

*<sup>x</sup>*¯ = 309.0 sd = 66.0

Thorough reading 196 ms Skimming 192 ms Spell checking 221 ms Regular reading 197 ms English L1 200–250 ms Afrikaans L2 300+ ms

H(2) = 0.3, p > 0.05 H(3) = 0, p > 0.05 H(3) = 0,

**Regressions (n) Regression %**

*<sup>x</sup>*¯ = 9.0 sd = 3.5

*<sup>x</sup>*¯ = 10.5 sd = 5.3

*<sup>x</sup>*¯ = 12.3 sd = 5.8

H(3) = 0, p > 0.05

English L1 10–15%

*<sup>x</sup>*¯ = 14.9 sd = 7.8

*<sup>x</sup>*¯ = 17.9 sd = 11.0

*<sup>x</sup>*¯ = 21.2 sd = 10.8

p > 0.05

the participants read screen 1, thus no distinction was made on the word level and the entire text piece was treated as a single AOI. **Table 3** shows these metrics,

**Figure 2.** *The gaze plot of one of the 'jumping barkers'.*

*Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

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

remaining metric analyses and only the barkers and non-barkers were analysed. Thus for fixation and visit count and saccadic amplitude, the jumping barkers were excluded. The non-barkers were then further subdivided based on their comprehension scores as per the reading levels of Halladay [19] as frustration readers—comprehension scores lower than 75%—and instructional and independent readers were grouped together as moderate readers. To answer the first research question, regarding the comparison of the barkers' eye movements during reading with that of their peers, Kruskal-Wallis statistical tests were performed between the three groups for each reading metric. A Friedman ANOVA was also applied to the per-line reading metrics of each group to determine whether reading behaviour varied significantly between the lines. For both these analyses, p < 0.05 is taken as showing statistical significance. Descriptive analyses were performed to answer the remaining research questions, with gaze plots and comparisons between average measurements and those found in the literature drawn on to guide

The images below are gaze plots and serve to qualitatively illustrate the different

**Figure 2** is an example of one of the jumping barkers who is clearly not reading but rather exhibiting clusters of fixations interspersed with large saccades—or

**Figure 1** is a gaze plot of the strongest reader in the group. From this it can clearly be seen that the reader fixated on most words. Durations, as reflected by the size of the fixation points, fluctuate within acceptable ranges. Some fixations are slightly offset but it can clearly be seen that reading is occurring at a steady pace

**368**

**Figure 2.**

**Figure 1.**

*The gaze plot of one of the 'jumping barkers'.*

such descriptions.

**5.1 Qualitative discussion**

with regular reading behaviour.

reading behaviours which were evident in the sample.

*The gaze plot of the strongest of the learners in the 'moderate reader' category.*

**5. Results**

jumps. Fixations are more erratic and spread wildly over the body of the text and no regular pattern is discernible except in short spurts hence they are not habitual barkers but instead tend to skip large parts of the text. Durations also remain fairly constant for this jumper.

**Figure 3** is one of the regular barkers, but here it can be seen that the fixations closely relate to regular reading. There is a regular pattern, fixations are spread over the whole text and on each word the durations fluctuate. This type of pattern is representative of the majority of the barkers and it can be deduced that the behaviour very closely mimics proper reading.

### **5.2 Reading metrics for whole text**

This section discusses the metrics which were analysed for the whole text while the participants read screen 1, thus no distinction was made on the word level and the entire text piece was treated as a single AOI. **Table 3** shows these metrics,

**Figure 3.** *The gaze plot of one of the 'regular barkers'.*


#### **Table 3.**

*A summary of the analysis for the metrics calculated over the whole piece of text for all participants.*

together with the range of expected values that could be obtained from previous literature. The ranges were read from graphs that were reported and as such are approximate values which will be used for reference to aid the comparison.

Since the reading speed is measured as milliseconds per characters, higher values actually indicate a slower reading speed in this instance. From the mean values in the table above, it can be seen that the reading speed is slightly lower for the barkers than the readers, but not significantly so. Surprisingly, the poor readers had the fastest speed. Fixation durations are lower for the barkers than the other groups and they have fewer regressions and a lower regression percentage. For English first language silent reading it is accepted that the average fixation is between 200 and 250 ms. When experiencing reading difficulty, fixations will be longer, hence this could be indicative of the nature of the text and the attempt to process and understand the text. However, for these participants, English is not their first language but it is their language of instruction. As such, the fixation durations are closer to what would be expected from a second language reader as evidenced in [45]. Interestingly the barkers had the lowest fixation duration perhaps indicating the lower cognitive processing that was occurring. Regression percentage of the moderate readers is in line with what one would expect of English L1 reading. Given the nature of the text, one might expect more regressions as readers attempt to make sense of the scientific content. Poor readers and barkers have fewer regressions, which is contrary to what is expected when experiencing reading difficulty. Once again, the contrary findings for the barkers could be indicative of the lack or lower cognitive processing which is occurring.

As shown in **Table 4**, barkers have fewer fixations and longer saccades than the poor and moderate readers, although not significantly so. For L2 reading it is expected that saccades will be shorter and there will be more fixations. Skimming exhibits larger saccades while spell checking has shorter saccades. Therefore, the saccadic amplitude is contradictory to previous findings and veers towards skimming behaviour. The fact that regressive saccades were included in the data could account for the larger saccadic amplitude if the regressions were large. However, barkers had fewer saccades and therefore the longer saccades perhaps indicates the tendency not to concentrate on words in order to assimilate them but instead to mimic the behaviour of reading and thus not always to exhibit the saccade amplitude required to process and understand words. The actual nature of the saccades should be investigated in more depth in order to determine whether the cause is large backwards or forwards regressions. What should be kept in consideration is that, on average, the difference is very small and could thus not be on a scale that makes a difference to the number of fixations per word which will be analysed next.


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*\**

**Table 5.**

Poor readers

Moderate readers

Kruskal-Wallis

*Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

**5.3 First pass reading of text and per word analysis**

words but within the body of the text.

Barkers\* <sup>23</sup> *<sup>x</sup>*¯ = 300.4

**N First fixation duration (ms)**

<sup>25</sup> *<sup>x</sup>*¯ = 318.8

<sup>19</sup> *<sup>x</sup>*¯ = 307.9

*A summary of the metrics for first pass reading of text.*

sd = 64.7

sd = 46.8

sd = 74.0

H(2) = 2.8, p > 0.05

*Barkers includes jumping and regular barkers due to the nature of these metrics.*

that is occurring.

than the readers.

Without a reference to the number of fixations per word it is difficult to determine whether the barkers have fixations similar to any other type of reading. However, it can clearly be seen that, on average, barkers have fewer fixations than the poor and moderate readers which once again could indicate the lack of cognitive processing

In summary, while none of the differences are significant it is noticeable that the behaviour of the barkers mimics that of very good readers (apart from the speed), even giving the impression that they are experiencing less difficulty with the text

The mean first fixation duration for all words over the whole text was calculated for each participant as a measurement of a first pass at the text. Furthermore, the average fixation duration, the total fixation duration and fixation count was calculated as a function of the words—that is, each word was treated as a separate AOI and the mean values were calculated as such. This will give an indication of the behaviour on a per word level showing how long, on average, each word required and how many revisits or refixations each word required. The summary of the metrics is given in **Table 5**. Similar to the fixation duration over the whole text, barkers have the shortest first fixation duration. This metric is indicative of the cognitive processing which is required to process the word on the first pass reading. In this instance, the poor readers required the longest initial processing time which confirms the fact they could be experiencing difficulty on the first pass which is not unexpected. The barkers are clearly not spending more time processing the words. When comparing the first fixation duration to the overall fixation duration, the values for the barkers is very similar, only differing by 4 ms. The poor readers have, on average, first fixations which are approximately 8 ms longer but the moderate readers have lower first fixations than overall fixations. However, when inspecting mean fixation durations per word in the **Table 5**, it is only the barkers who remain unchanged while both the poor and moderate readers have lower mean fixation durations, showing an increase in processing when first encountering the word. The difference between these and the values in the previous section could be attributed to the settings of the AOIs, hence there are some fixations which are outside the bounds of the individual

The number of fixations and visits per word are very similar between the groups indicating that on this level the reading behaviour closely resembles one another (**Table 6**). This confirms that the minor difference in saccadic amplitude

> **Mean fixation duration (ms)**

> > *<sup>x</sup>*¯ = 300.4 sd = 61.6

*<sup>x</sup>*¯ = 309.2 sd = 46.2

*<sup>x</sup>*¯ = 306.3 sd = 66.3

H(2) = 0.7, p > 0.05

**Total fixation duration (ms)**

> *<sup>x</sup>*¯ = 495.2 sd = 93.3

*<sup>x</sup>*¯ = 485.2.4 sd = 96.4

*<sup>x</sup>*¯ = 502.6 sd = 151.9

H(2) = 0.3, p > 0.05

**Mean visit duration (ms)**

> *<sup>x</sup>*¯ = 335.7 sd = 75.4

> *<sup>x</sup>*¯ = 347.6 sd = 54.4

> *<sup>x</sup>*¯ = 345.3 sd = 77.7

H(2) = 0.7, p > 0.05

#### **Table 4.**

*Fixation count and saccadic amplitude over the whole text excluding jumping barkers.*

#### *Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

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

together with the range of expected values that could be obtained from previous literature. The ranges were read from graphs that were reported and as such are approximate values which will be used for reference to aid the comparison.

Since the reading speed is measured as milliseconds per characters, higher values actually indicate a slower reading speed in this instance. From the mean values in the table above, it can be seen that the reading speed is slightly lower for the barkers than the readers, but not significantly so. Surprisingly, the poor readers had the fastest speed. Fixation durations are lower for the barkers than the other groups and they have fewer regressions and a lower regression percentage. For English first language silent reading it is accepted that the average fixation is between 200 and 250 ms. When experiencing reading difficulty, fixations will be longer, hence this could be indicative of the nature of the text and the attempt to process and understand the text. However, for these participants, English is not their first language but it is their language of instruction. As such, the fixation durations are closer to what would be expected from a second language reader as evidenced in [45]. Interestingly the barkers had the lowest fixation duration perhaps indicating the lower cognitive processing that was occurring. Regression percentage of the moderate readers is in line with what one would expect of English L1 reading. Given the nature of the text, one might expect more regressions as readers attempt to make sense of the scientific content. Poor readers and barkers have fewer regressions, which is contrary to what is expected when experiencing reading difficulty. Once again, the contrary findings for the barkers could be indicative of the lack or lower cognitive processing which is occurring. As shown in **Table 4**, barkers have fewer fixations and longer saccades than the poor and moderate readers, although not significantly so. For L2 reading it is expected that saccades will be shorter and there will be more fixations. Skimming exhibits larger saccades while spell checking has shorter saccades. Therefore, the saccadic amplitude is contradictory to previous findings and veers towards skimming behaviour. The fact that regressive saccades were included in the data could account for the larger saccadic amplitude if the regressions were large. However, barkers had fewer saccades and therefore the longer saccades perhaps indicates the tendency not to concentrate on words in order to assimilate them but instead to mimic the behaviour of reading and thus not always to exhibit the saccade amplitude required to process and understand words. The actual nature of the saccades should be investigated in more depth in order to determine whether the cause is large backwards or forwards regressions. What should be kept in consideration is that, on average, the difference is very small and could thus not be on a scale that makes a difference to the number of fixations per word which will be analysed next.

**N Fixation count (n) Saccadic amplitude (visual angle)**

*<sup>x</sup>*¯ = 1.9, sd = 0.1

*<sup>x</sup>*¯ = 1.8, sd = 0.1

*<sup>x</sup>*¯ = 1.8, sd = 0.1

H(2) = 1.8, p > 0.05

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**Table 4.**

*\**

Regular barkers\* <sup>13</sup> *<sup>x</sup>*¯ = 163.2,

Poor readers <sup>25</sup> *<sup>x</sup>*¯ = 165.9,

Moderate readers <sup>19</sup> *<sup>x</sup>*¯ = 175.9,

Kruskal-Wallis H(2) = 1.2,

sd = 25.0

sd = 37.1

sd = 44.1

p > 0.05

*Due to the nature of the metrics jumping barkers are excluded from this analysis.*

*Fixation count and saccadic amplitude over the whole text excluding jumping barkers.*

Expected values English L1 7–9 characters

Without a reference to the number of fixations per word it is difficult to determine whether the barkers have fixations similar to any other type of reading. However, it can clearly be seen that, on average, barkers have fewer fixations than the poor and moderate readers which once again could indicate the lack of cognitive processing that is occurring.

In summary, while none of the differences are significant it is noticeable that the behaviour of the barkers mimics that of very good readers (apart from the speed), even giving the impression that they are experiencing less difficulty with the text than the readers.

#### **5.3 First pass reading of text and per word analysis**

The mean first fixation duration for all words over the whole text was calculated for each participant as a measurement of a first pass at the text. Furthermore, the average fixation duration, the total fixation duration and fixation count was calculated as a function of the words—that is, each word was treated as a separate AOI and the mean values were calculated as such. This will give an indication of the behaviour on a per word level showing how long, on average, each word required and how many revisits or refixations each word required. The summary of the metrics is given in **Table 5**.

Similar to the fixation duration over the whole text, barkers have the shortest first fixation duration. This metric is indicative of the cognitive processing which is required to process the word on the first pass reading. In this instance, the poor readers required the longest initial processing time which confirms the fact they could be experiencing difficulty on the first pass which is not unexpected. The barkers are clearly not spending more time processing the words. When comparing the first fixation duration to the overall fixation duration, the values for the barkers is very similar, only differing by 4 ms. The poor readers have, on average, first fixations which are approximately 8 ms longer but the moderate readers have lower first fixations than overall fixations. However, when inspecting mean fixation durations per word in the **Table 5**, it is only the barkers who remain unchanged while both the poor and moderate readers have lower mean fixation durations, showing an increase in processing when first encountering the word. The difference between these and the values in the previous section could be attributed to the settings of the AOIs, hence there are some fixations which are outside the bounds of the individual words but within the body of the text.


The number of fixations and visits per word are very similar between the groups indicating that on this level the reading behaviour closely resembles one another (**Table 6**). This confirms that the minor difference in saccadic amplitude

#### **Table 5.**

*A summary of the metrics for first pass reading of text.*

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


#### **Table 6.**

*The average number of fixations and visits per word excluding the jumping barkers.*

is not of the order that barkers fixate on individual words less. The number of fixations is much higher than the average of 1.2, which is used as a measurement of age appropriate difficulty, suggesting that in all instances the participants were perhaps experiencing some difficulty. Of course, the fact that they were reading a scientific text as opposed to a piece of fiction could naturally change their reading behaviour.

#### **5.4 Reading behaviour spread over text (uniformity)**

In order to investigate whether the reading behaviour was uniform over the whole text, some metrics were calculated for each line. These metrics were average fixation duration per line, reading speed (milliseconds per character) and mean number of fixations per word.

The metrics were compared for barkers and non-barkers separately as a repeated measure to determine if their behaviour changed significantly as they read the text. A Friedman ANOVA was used for this purpose.

Additionally, some graphs are given in order to illustrate the distribution of behaviour over the text, in some instances the metrics are not analysed statistically.

#### **5.5 Fixation duration**

There was a significant difference in the line reading for barkers (χ<sup>2</sup> = 23.4, p < 0.05, p < 0.01), poor readers (χ<sup>2</sup> = 24.8, p < 0.05, p < 0.01) but not for moderate readers (χ<sup>2</sup> = 0.9, p > 0.05) for the mean fixation duration. For barkers, the significant difference could be attributed to a difference between lines 1 and 2, 4, and 5. For poor readers, line 1 differed significantly from lines 2, 3, 4 and 5.

From the graph below, it can clearly be seen that the mean fixation durations for line 1 are lower than for the other lines from **Figure 4**.

The number of words per line in increasing order is lines 1, 3, 5, 4, 2. Interestingly the fixation duration of the barkers imitates this order in ascending order with the lowest average fixation duration on line 1 and the highest average fixation duration on line 2. This is not true for the poor and moderate readers who have, in ascending order of mean fixation duration, lines 1, 2, 4, 5, 3 and lines 1, 5, 2, 3, 4 respectively. In this respect, it appears the barkers adjust their behaviour according to the length of the line they are currently reading.

In terms of the difficulty, the two longest lines, namely lines 2 and 4 are also the lines which contain the most scientific content and concepts. Line 1 can be considered the easiest as it contains only everyday language and line 3 contains easier words and shorter sentences than lines 2 and 4. Hence in terms of length lines 1 and 3 are the shortest and in terms of difficulty also the easiest while lines

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study.

**Figure 4.**

**5.6 First fixation duration**

*Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

2 and 4 are both the longest and most difficult. Line 5 contains some words which may be unfamiliar to the participants but contains no scientific concepts and can thus be considered to be easier than lines 2 and 4. Therefore, the difficulty of the lines coincidentally mimics the length of the lines. Therefore, further investigation is required in order to determine whether the difficulty of the words in the line

**Figure 5** gives an indication of mean time spent on words in the order the words appeared in the text. The vertical dashed lines indicate the lines of text. Clearly the first line has the lowest fixation durations for all groups but there are clear spikes and dips in the durations for each of the groups. An in-depth analysis of the length and difficulty of the word, together with the surrounding words, or concept, will possibly shed more light on the behaviour difference detected. However, that is beyond the scope of this chapter and will be analysed in a further

**Figure 6** shows the first fixation duration per word, in order of words over the text. From the graph it can be seen that for all groups the first fixation durations fluctuate across the text. The values do not appear to plateau based on the position of the word nor do they hold steady as one might expect for mindless reading. While the patterns are similar in some instances, i.e. all the groups decrease or increase for some words, it can be said that in some other instances there are different patterns where some groups increase and others decrease. Similar to the mean fixation durations, an individual word analysis which may provide more insight into the cause of the reading behaviour is beyond the scope of this chapter. For interest sake, some of the words and their associated behaviour will be discussed in an anecdotal manner, leaving in-depth analysis for a further study. For example, the word "potential" caused an increase in first fixation duration. The word potential preceded the word "difference" as the scientific concept of potential difference was under discussion. However, the word "difference" did not cause an increase in first fixation duration, nor did it have

impacted the behaviour of the barkers or not.

*Mean fixation durations per line for each participant group.*

#### *Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

**Figure 4.**

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

Regular barkers\* <sup>13</sup> *<sup>x</sup>*¯ = 1.6

Poor readers <sup>25</sup> *<sup>x</sup>*¯ = 1.6

Moderate readers <sup>19</sup> *<sup>x</sup>*¯ = 1.6

*Due to the nature of the metrics jumping barkers are excluded from this analysis.*

*The average number of fixations and visits per word excluding the jumping barkers.*

**N Fixation count (n) Visit count (n)**

sd = 0.2

sd = 0.2

sd = .2

Kruskal-Wallis H(2) = 1.7, p > 0.05 H(2) = 1.7, p > 0.05

is not of the order that barkers fixate on individual words less. The number of fixations is much higher than the average of 1.2, which is used as a measurement of age appropriate difficulty, suggesting that in all instances the participants were perhaps experiencing some difficulty. Of course, the fact that they were reading a scientific text as opposed to a piece of fiction could naturally change their reading

In order to investigate whether the reading behaviour was uniform over the whole text, some metrics were calculated for each line. These metrics were average fixation duration per line, reading speed (milliseconds per character) and mean

Additionally, some graphs are given in order to illustrate the distribution of behaviour over the text, in some instances the metrics are not analysed statistically.

cant difference could be attributed to a difference between lines 1 and 2, 4, and 5.

In terms of the difficulty, the two longest lines, namely lines 2 and 4 are also the lines which contain the most scientific content and concepts. Line 1 can be considered the easiest as it contains only everyday language and line 3 contains easier words and shorter sentences than lines 2 and 4. Hence in terms of length lines 1 and 3 are the shortest and in terms of difficulty also the easiest while lines

From the graph below, it can clearly be seen that the mean fixation durations for

There was a significant difference in the line reading for barkers (χ<sup>2</sup>

The number of words per line in increasing order is lines 1, 3, 5, 4, 2. Interestingly the fixation duration of the barkers imitates this order in ascending order with the lowest average fixation duration on line 1 and the highest average fixation duration on line 2. This is not true for the poor and moderate readers who have, in ascending order of mean fixation duration, lines 1, 2, 4, 5, 3 and lines 1, 5, 2, 3, 4 respectively. In this respect, it appears the barkers adjust their behaviour

For poor readers, line 1 differed significantly from lines 2, 3, 4 and 5.

line 1 are lower than for the other lines from **Figure 4**.

according to the length of the line they are currently reading.

The metrics were compared for barkers and non-barkers separately as a repeated measure to determine if their behaviour changed significantly as they read the text.

= 0.9, p > 0.05) for the mean fixation duration. For barkers, the signifi-

= 23.4,

*<sup>x</sup>*¯ = 1.5 sd = 0.2

*<sup>x</sup>*¯ = 1.4 sd = 0.2

*<sup>x</sup>*¯ = 1.5 sd = 0.2

= 24.8, p < 0.05, p < 0.01) but not for moderate

**5.4 Reading behaviour spread over text (uniformity)**

A Friedman ANOVA was used for this purpose.

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behaviour.

*\**

**Table 6.**

number of fixations per word.

p < 0.05, p < 0.01), poor readers (χ<sup>2</sup>

**5.5 Fixation duration**

readers (χ<sup>2</sup>

*Mean fixation durations per line for each participant group.*

2 and 4 are both the longest and most difficult. Line 5 contains some words which may be unfamiliar to the participants but contains no scientific concepts and can thus be considered to be easier than lines 2 and 4. Therefore, the difficulty of the lines coincidentally mimics the length of the lines. Therefore, further investigation is required in order to determine whether the difficulty of the words in the line impacted the behaviour of the barkers or not.

**Figure 5** gives an indication of mean time spent on words in the order the words appeared in the text. The vertical dashed lines indicate the lines of text. Clearly the first line has the lowest fixation durations for all groups but there are clear spikes and dips in the durations for each of the groups. An in-depth analysis of the length and difficulty of the word, together with the surrounding words, or concept, will possibly shed more light on the behaviour difference detected. However, that is beyond the scope of this chapter and will be analysed in a further study.

#### **5.6 First fixation duration**

**Figure 6** shows the first fixation duration per word, in order of words over the text. From the graph it can be seen that for all groups the first fixation durations fluctuate across the text. The values do not appear to plateau based on the position of the word nor do they hold steady as one might expect for mindless reading. While the patterns are similar in some instances, i.e. all the groups decrease or increase for some words, it can be said that in some other instances there are different patterns where some groups increase and others decrease. Similar to the mean fixation durations, an individual word analysis which may provide more insight into the cause of the reading behaviour is beyond the scope of this chapter. For interest sake, some of the words and their associated behaviour will be discussed in an anecdotal manner, leaving in-depth analysis for a further study. For example, the word "potential" caused an increase in first fixation duration. The word potential preceded the word "difference" as the scientific concept of potential difference was under discussion. However, the word "difference" did not cause an increase in first fixation duration, nor did it have

**Figure 5.** *Mean fixation duration per word, in word order for each participant group.*

**Figure 6.** *First fixation duration per word for each participant group.*

the same magnitude duration as "potential" suggesting that the participants were perhaps treating the text on a word-by-word basis and not processing concepts created by successive words. The poor readers had much higher instances of first fixation durations for many words in line 2, which was the most difficult line. Furthermore, for poor readers the words "collide" and "crystals" caused the highest and second highest first fixation duration on line 2. These could be considered to be more difficult words, hence the increase in first pass processing for this particular group.

#### **5.7 Total fixation duration**

**Figure 7** shows the total fixation duration per word in the order the words appeared in the text. Similar to previous per word metrics, these also fluctuate. As one would expect there are some larger spikes on line 2 which was classified as the most difficult line. For example, looking at the larger duration on word number 25, the word is "enormous" and refers to an "enormous electrical field". The word "enormous" might have been a particularly difficult word for the participants. The first fixation duration on this word was also high for all groups. Barkers also had, on average, an increased duration on the word "potential" for the concept "potential

**375**

**Table 7.**

Line 4

*Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

**5.8 Reading speed**

readers (χ<sup>2</sup>

**Figure 7.**

of the sentence "ice crystals inside the clouds…".

was a significant difference for the poor readers (χ<sup>2</sup>

*Total fixation duration per word for each participant group.*

Line 1 B

denotes poor readers and M denotes moderate readers.

= 22.3, p < 0.05).

difference", as with the first fixation duration. The increase for poor and moderate readers at word number 38 and 39 was caused by the words "ice crystals" at the start

Comparing this graph to the graph of mean fixation durations for line 1, it appears that the participants spent a longer time in total at the start of the line, perhaps as they were getting into the reading pattern and settling down.

Reading speed was calculated for each line as milliseconds per character. There

at an alpha-level of 0.05 but it can be considered significant at a level of 0.1. There

Significant differences are plotted in the **Table 7**, where B denotes barker, P

The table clearly shows that for the majority of the cases the same lines account for significant differences in each of the groups. Inspecting **Figure 8** shows that the

**Line 2 Line 3 Line 4 Line 5**

Line 2 B B B

Line 3 B

*Summary of significant difference in reading speeds between lines.*

P P P M M M

P P P M M M

P

P

= 9.3, p = 0.05)

= 45.9, p < 0.05) and moderate

was no significant difference between the lines for the barkers (χ<sup>2</sup>

#### *Eye Movements during Barking at Print DOI: http://dx.doi.org/10.5772/intechopen.81898*

difference", as with the first fixation duration. The increase for poor and moderate readers at word number 38 and 39 was caused by the words "ice crystals" at the start of the sentence "ice crystals inside the clouds…".

Comparing this graph to the graph of mean fixation durations for line 1, it appears that the participants spent a longer time in total at the start of the line, perhaps as they were getting into the reading pattern and settling down.
