1. Gemma Fitzsimmons, Mark J Weal and Denis Drieghe
Reading for Comprehension versus Skim Reading on the Web: How Skim Reading is Informed by Hyperlinks
Gemma Fitzsimmons, Mark J Weal and Denis Drieghe
The Influence of Hyperlinks on Reading on the Web: An Empirical Approach.

2. Reading Research
A majority of the reading research involves reading for comprehension of single sentences. After a number of these sentences simple yes/no questions are asked ensuring that readers are indeed reading for comprehension
However, in every day life our reading experiences are often quite different
Format: Paragraph versus single sentence (e.g. early eye movements faster in paragraph reading, Radach, Huestegge & Reilly, 2008)
Task: Reading for comprehension vs. proofreading vs. skim reading

3. Reading on the Web: The Influence of Hyperlinks
One difference between reading off-line and reading hypertext that is likely to influence how people read on the Web is the presence of hyperlinks
Hyperlinks denote a connection to other content somewhere else on the Web
Hyperlinks are coloured and salient compared to the rest of the text (Low-level influence)
Lexical information of the word that is hyperlinked
If we consider high-level processes those based on information not contained within the lexical representation of a word, then there is high level information attached to a hyperlink. A hyperlink links one piece of information to another, perhaps on a separate page of the same Website, or a different Website

4. How do we Read Hypertext?
Very little experimental research so far, mostly focused on Human Computer Interaction (HCI)
Nielsen (1999) claims that “the mother of bad design conventions is the decision to make hypertext links blue”. However, he also admits that hyperlinks being denoted in blue is now a convention and we should not move away from it
Carr (2010) suggests that hyperlinks are a distraction in text and hinder comprehension
Closest thing to a prediction: E-Z Reader - Reichle et al (2009) suggest that higher-level, post-lexical processes intervene in eye movement control only when “something is wrong” and either send a signal to stop moving forward (longer fixation or re- fixation) or a signal to execute a regression => exclusively impact later eye movement measures.

5. Reading on the Web: Set of Experiments
Experiment 1: We start with a simple experiment looking into saliency
Experiment 2: We then look into the influence of hyperlinks on reading for comprehension
Experiment 3: Pulling apart saliency and hyperlinks
With the large amount of information available to us on the Web we need a strategy to sort through all of the text presented to us = skim reading
Experiment 4: Reading for comprehension vs skim reading on the Web and examining whether hyperlinks can guide skim reading

6. All Experiments Eyelink 1000
Reading for comprehension - occasional yes/no questions (unless of course in condition of skim reading in last experiment)
Linear Mixed Models
In most of the analyses presented here the LMM’s were run on the raw fixation times and are presented as such for transparency. When the data either deviated from the normal distribution and/or log transformed data resulted in qualitatively different models, we present the log transformed data
Random Factors: Participants and Items. “Full random structure”, pruned if the model did not converge.
Initial models were all fixed factors with all higher order interactions. Where we did not have strong predictions about the higher-order interactions, we carried out model comparisons to see whether they added to the fit of the model and removed them if not

7. Experiment 1
Before examining whether hyperlinks influence reading behaviour, we first examine whether there is indeed a negative influence of the hyperlink being salient/coloured outside of hypertext, so when it would not be perceived as a hyperlink.

8. Experiment 1
Before examining whether hyperlinks influence reading behaviour, we first examine whether there is indeed a negative influence of the hyperlink being salient/coloured outside of hypertext, so when it would not be perceived as a hyperlink.
30 participants
30 sentences
5 conditions: Colour of the target word

9. Experiment 1 : Word skipping

10. Experiment 1: Fixation times
Longer fixation times on Grey (early and late measures) and on Green (late measures)

11. Experiment 1: Discussion
There was an influence of the colour in that coloured words were skipped less often than the black word
Fixation times were not influenced by the colouring with the exception of grey (early and late fixation measures) and green (only in late measures)
We had expected a longer fixation times on grey due to the reduced contrast associated with the condition (see also Drieghe, 2008; Reingold & Rayner, 2006). After measuring candela using a photometer we discovered that green actually also had reduced contrast compared to the other colours. But we are not sure why this would impact the later measurements exclusively
=> For the crucial blue versus black comparison: Less skipping, no effect on fixation times

12. Experiment 2
The coloured words are embedded in edited Wikipedia pages, essentially becoming hyperlinks
We also included a frequency manipulation. This allowed us to examine interactions with lexical processing and to show the statistical power of our design if hyperlinks were read as normal words
In this experiment, no clicking yet
Word Frequency
Word
Type

13. Experiment 2 Stimuli
32 participants (30 took part in Experiment 1 which was run first)
20 edited Wikipedia pages
80 target words, one per sentence, 4 sentences per Wikipedia article

14. Experiment 2 Stimuli
Demand/rigour
Phone/scarf
Salt/grit
Sleep/inert

15. Experiment 2 Results
No effects on Word Skipping, we did not replicate reduced skipping of a coloured word which was observed in Experiment 1.

16. Experiment 2 Results
In early measures (FFD - SFD - GD) only effect of frequency, no effect of hyperlinking.

17. Experiment 2 Results
Late measures (Go-past & TT): Interaction between Frequency and hyperlinking.

18. Experiment 2 Results
Hyperlinked, low-frequency words were associated with longer late fixation duration measures.
The effect in total reading time is not due to re-reading after they have left the hyperlinked word there was no difference in regressions in (but there was in regressions out).

19. Experiment 2: Discussion
Experiment 2 – Longer times in late measures for Low frequent/Hyperlinked words
Yes, hyperlinked words are processed differently to coloured words, but only for low-frequency words
Extra high level information contained in a hyperlink, presumably the suggestion of additional information
Potentially compatible with E-Z Reader (Reichle et al, 2009). Higher-level processes intervene in later measures only when the processing is difficult
Parts of these findings were published in 2013 as a conference proceeding and were independently replicated by Gagl (2016) who found no effects of hyperlinking on early measures but did find longer re-reading times. His stimuli would have been in our Low frequency condition

20. Experiment 2: Discussion
We did not replicate the finding from Experiment 1 that coloured words were skipped less
We assumed the original finding (reduced skipping of a coloured word) is likely due to a low-level factor, i.e. saliency
However, in the hyperlink experiments multiple words were coloured. This might have influenced the saliency
If this is true, we might not find the reduced skipping of a coloured word when multiple words are coloured

21. Experiment 3 36 Participants 72 sentences
Number of blue words (0/1/3) x Frequency (HF/LF)

22. Experiment 3: Word Skipping
Effect of Frequency (HF > LF)
Target word gets skipped less when in colour but only when it is the only word in colour. (see also Experiment 1).

23. Experiment 3: Fixation times
Frequency Effect
Replication of Experiment 1: No Effect of Colour Blue on Fixation times.

24. Experiment 3: Discussion
Strong evidence that hyperlinks will not disrupt normal reading simply on the basis of being a coloured word
When multiple coloured words, no effect on skipping rates and no effect on fixation times
The only effect is reduced skipping of a coloured word but only when it is the only one (Experiment 1)

25. Reading on the Web: Set of Experiments
Experiment 1: We start with a simple experiment looking into saliency
Experiment 2: We then look into the influence of hyperlinks on reading for comprehension
Experiment 3: Pulling apart saliency and hyperlinks
With the large amount of information available to us on the Web we need a strategy to sort through all of the text presented to us = skim reading
Experiment 4: Reading for comprehension vs skim reading on the Web and examining whether hyperlinks can guide skim reading

26. Just & Carpenter (1987)/ Just, Carpenter, & Masson (1982)
Normal reading, skim reading and speed reading Skim readers were compared to normal readers:
2.5 times faster than normal readers
Shorter fixations (100 ms less per fixation)
Smaller frequency and word length effects in fixation times
More often skipping over multiple words. Also, big word length effects on word skipping but no differences in skipping content vs. function words, which was present for the normal readers
Reduced comprehension, clear trade-off

27. Frequency and Task Effects
A High-Frequency word receives shorter fixation durations than a Low-Frequency word (Inhoff & Rayner, 1986).
Compared to the frequency effect in normal reading:
Skim reading: Reduced frequency effect (Just & Carpenter, 1987)
Visual search for a word in a text: no frequency effect (Rayner & Raney, 1996) - rapid surface comparison vs. full lexical access
Proofreading: Bigger frequency effect (Kaakinen & Hyönä, 2010) - postlexical checking of correct word form

28. Reading for Comprehension vs. Skim Reading on the Web
Predictions:
Faster reading times for skim readers
Reduced comprehension for skim readers
Hypothesis that when skim reading the hyperlinks would become anchor points to target because they might indicate the location of important information
Increased skipping for skim reading compared to reading for comprehension but to a lesser extent for hyperlinks
Frequency effects reduced for unlinked words during skim reading. But linked words might show a frequency effect similar to normal reading

29. Experiment 4 32 participants - 8 conditions
2 (Task Type) x 2 (Word Type) x 2 (Word Frequency)
40 texts - (20 read normally - 20 skimming, in that order). Instructions were to skim read as they would normally do when having to read a large amount of text
Each text had 4 target words, leading to 160 target words. Average word length 5.6 characters
Word Frequency
Task Type
Read normally
Word
Type
Skim read

30. Experiment 4: Results
Participants read faster when skim reading (39 seconds per trial) than reading for comprehension (20 sec, t(31) = 17.28, p <.001)
Participants read faster when skim reading (39 seconds per trial) than reading for comprehension (20 sec, t(31) = 17.28, p <.001)
Skipping probabilities
Single Fixation Duration (94% when fixated)
Go- Past Time

31. Experiment 4: Skipping probability
Large skipping rates
Main effect of frequency. Skipping HF > LF.
Interaction between Word Type and Task Type: Unlinked Words get skipped more during skim reading

32. Single fixation durations
Three way interaction, so we ran contrasts:
Normal reading: Frequency Effect both for the linked and unlinked words (replication Fitzsimmons, Weal & Drieghe, 2013)
Single Fixation Durations shorter in skimming
For the Skim readers Frequency Effect for Linked but not for Unlinked words

33. Go-past Times
Messy Data. You can see that we could not remove any of the interactions even though none are significant.
Main effect of frequency
Main effect of Task type with less rereading in skim reading.
Although regressions were not rare when the target word was fixated (14.11%), the combination with the high skipping rates leads to not much trials with a regression.

34. Reading for Comprehension vs. Skim Reading on the Web
Predictions:
Faster reading times for skim readers
Reduced comprehension for skim readers
Hypothesis that when skim reading the hyperlinks would become anchor points to target because they might indicate the location of important information
Increased skipping for skim reading compared to reading for comprehension but to a lesser extent for hyperlinks
Frequency effects reduced for unlinked words during skim reading. But linked words might show a frequency effect similar to normal reading

35. Practical implications
When designing a webpage be aware of the fact that readers will use hyperlinks to skim read through your text so try to make the links relevant to the content of the website
Hyperlinks can assist the readers with navigating through the text

36. Other related work
Importance and hyperlinks – do hyperlinks suggest important sections of text, can the reader use hyperlinks to inform reading/skim reading?
Clicking and navigating – the impact of having to navigate through Webpages on comprehension

37. Thank you for your attention!