Successfully reported this slideshow.

Challenging Information Foraging Theory: Screen Reader Users are not Always Driven by Information Scent

1

Share

Loading in …3
×
1 of 24
1 of 24

Challenging Information Foraging Theory: Screen Reader Users are not Always Driven by Information Scent

1

Share

Download to read offline

Little is known about the navigation tactics employed by screen reader users when they face problematic situations on the Web. Understanding how these tactics are operationalised and knowing the situations that bring about such tactics paves the way towards modeling navigation behaviour. Modeling the navigation of users is of utmost importance as it allows not only to predict interactive behaviour, but also to assess the appropriateness of the content in a link, the information architecture of a site and the design of a web page. Current navigation models do not consider the extreme adaptations, namely coping tactics, that screen reader users undergo on the Web. Consequently, their prediction power is lessened and coping tactics are mistakenly considered outlying behaviours. We draw from existing navigation models for sighted users to suggest the incorporation of emerging behaviours in navigation models for screen reader users. To do so, we identify the navigation coping tactics screen reader users exhibit on the Web, including deliberately clicking on low scented links, escaping from useless or inaccessible content and backtracking to a shelter. Our findings suggest that, especially in problematic situations, navigation is not driven by information scent or utility, but by the need of increasing autonomy and the need of escaping from the current web patch.

Little is known about the navigation tactics employed by screen reader users when they face problematic situations on the Web. Understanding how these tactics are operationalised and knowing the situations that bring about such tactics paves the way towards modeling navigation behaviour. Modeling the navigation of users is of utmost importance as it allows not only to predict interactive behaviour, but also to assess the appropriateness of the content in a link, the information architecture of a site and the design of a web page. Current navigation models do not consider the extreme adaptations, namely coping tactics, that screen reader users undergo on the Web. Consequently, their prediction power is lessened and coping tactics are mistakenly considered outlying behaviours. We draw from existing navigation models for sighted users to suggest the incorporation of emerging behaviours in navigation models for screen reader users. To do so, we identify the navigation coping tactics screen reader users exhibit on the Web, including deliberately clicking on low scented links, escaping from useless or inaccessible content and backtracking to a shelter. Our findings suggest that, especially in problematic situations, navigation is not driven by information scent or utility, but by the need of increasing autonomy and the need of escaping from the current web patch.

More Related Content

Related Books

Free with a 14 day trial from Scribd

See all

Related Audiobooks

Free with a 14 day trial from Scribd

See all

Challenging Information Foraging Theory: Screen Reader Users are not Always Driven by Information Scent

  1. 1. Challenging Information Foraging Theory: Screen Reader Users are not Always Driven by Information Scent 24th ACM Conference on Hypertext and Social Media Hypertext 2013 Markel Vigo1 & Simon Harper2 University of Manchester (UK) 1: @markelvigo 2: @sharpic markel.vigo@manchester.ac.uk simon.harper@manchester.ac.uk http://dx.doi.org/10.6084/m9.figshare.695073
  2. 2. Problem • We do not know all the navigation tactics employed by screen reader users • Key to build navigation models • Lack of navigation models for screen reader users ACM Hypertext 20132 May 2013 2
  3. 3. Goal • Bridge the gap on the lack of knowledge on navigation tactics • Survey existing navigation models (for sighted user) • Inform navigation models to make robust models • Consider coping strategies ACM Hypertext 20132 May 2013 3
  4. 4. Navigation models • High certainty about a constrained universe • Predict user behaviour • Interaction models: GOMS, KLM • Evaluation of interfaces • Often used in research settings ACM Hypertext 20132 May 2013 4
  5. 5. Navigation models • Built on Information Foraging Theory (IFT) – Web page ≈ information patch – User ≈ consumer • Link selection= • Information scent (IS) measures the relevance of proximal cues that lead towards distal goals ACM Hypertext 20132 May 2013 Max E(Info_Value) E(Cost) é ë ê ù û ú 5
  6. 6. Navigation models • Models for sighted user differ on – The conceptualisation of information scent – On the strategy for page reading • Few empirical studies are based on link selection or navigation strategies • Low predictive power ACM Hypertext 20132 May 2013 6
  7. 7. Who are screen reader users • Blind users • Low vision users • Potentially generalisable to users of auditory interfaces: – Applications on the move: car, walking, cycling – Situationally disabled users ACM Hypertext 20132 May 2013 7
  8. 8. How do screen readers navigate • What do we know so far? • Behaviours occurring on ideal situations • How is the navigation when encountering: – Accessibility barriers – Design issues – Usability problems ACM Hypertext 20132 May 2013 8
  9. 9. Stereotypical behaviours ACM Hypertext 20132 May 2013 1. Miscellaneous top links 2. Mast header 4. Main content 5. Banner 3. Primary navigation links 6. 2ndary navigation links 7. Footer 8. Miscellaneous bottom links 1. Miscellaneous top links 2. Mast header 3. Primary navigation links 4. Main content 1. Miscellaneous top links 2. Mast header 3. Primary navigation links 4. Main content (a) Listening to content (b) Exhaustive scanning 9
  10. 10. Stereotypical behaviours ACM Hypertext 20132 May 2013 1. Miscellaneous top links 2. Mast header 4. Main content 5. Banner 3. Primary navigation links 6. 2ndary navigation links 7. Footer 8. Miscellaneous bottom links H 1. Miscellaneous top links 2. Mast header 3. Primary navigation links 4. Main content (d) Information scent driven gambling scanning: headings navigation H H H H H1. Miscellaneous top links 2. Mast header 3. Primary navigation links 4. Main content (c) Gambling scanning: skip line navigation skip 6 lines skip 5 lines skip 5 lines skip 5 lines 10
  11. 11. Analysis of coping tactics • Secondary analysis of 2 user studies – Ethnographic longitudinal – User test • 17 users • Isolated 9 coping tactics grouped by – Link selection tactics – Exploration tactics – Navigation tactics ACM Hypertext 20132 May 2013 11
  12. 12. Link selection tactics T1: Deliberately clicking on low scented links • Accessibility problems: – “I'm just going to click on one of these things, I don’t know what it is for ” • Information overload: – “when I was listening I heard the target link... you can have 30 or 230 links that you have to sit and listen to! ” ACM Hypertext 20132 May 2013 12
  13. 13. Link selection tactics T2: Clicking on any link • When coming across unexpected functionalities or content – On a linked keyword search where search box expected: “does not tell me where to do this ” – On a SERP that did not contain expected results: “found a few links, none directly what I want ” ACM Hypertext 20132 May 2013 13
  14. 14. Intra-page exploration tactics T3: Escaping from useless or inaccessible content by tabbing down T4: Fast tab/arrow down the page without completely listening to content – By default – On familiar pages – On content arranged according to some criterion ACM Hypertext 20132 May 2013 14
  15. 15. Intra-page exploration tactics T5: Gaining orientation • By going to the top of the page – “not sure where I am...if in doubt go back to the beginning ” • Users pay more attention in the second reading ACM Hypertext 20132 May 2013 15
  16. 16. Inter-page navigation tactics T6: Backtracking to a shelter • When user mobility is reduced – Getting stuck: “I seem to have come to a dead end here” – Looping behaviours: “I’ve got back to shorts again...shorts again!” ACM Hypertext 20132 May 2013 16
  17. 17. Inter-page navigation tactics T7: Re-checking • Fast revisitations as reassurance mechanisms T8: Retracing • Users retrace their steps from a shelter ACM Hypertext 20132 May 2013 17
  18. 18. Withdrawal T9: Giving up • Provoked by sequence of failures and unsuccessful interactions. • Observed on users who navigate with trouble and encounter an obstacle different to ones experienced. • E.g.: encountering accessibility barriers after escaping from a loop of pages ACM Hypertext 20132 May 2013 18
  19. 19. Implications Informing navigation models • Navigation models for sighted users mimic screen reader user behaviour in ordinary circumstances • To cover extraordinary circumstances minor modifications are needed: – Gaining orientation (T5) – Re-tracing (T8) ACM Hypertext 20132 May 2013 19
  20. 20. Implications Challenging established conceptions • In ordinary circumstances IS is a reliable indicator • In extraordinary circumstances users are not driven by IS but escape from problems – Click on low scented (t1) or any link (t2) – Fast tabbing down (t3, t4) – Backtracking to a shelter (t6) ACM Hypertext 20132 May 2013 20
  21. 21. Implications Challenging established conceptions • IFT: a hyperlink will be selected when the tradeoff between information gaining and cost of accessing is low • SR users: cost of accessing is minimised at the expenses of gaining low quality information • Alternatively, SR users have low satisficing levels: any web patch is good enough ACM Hypertext 20132 May 2013 21 Max E(Info_Value) E(Cost) é ë ê ù û ú
  22. 22. Implications Challenging established conceptions • This behaviour reminds of that of animals making risk-sensitive foraging decisions – Risk prone individuals: those undergoing extreme situations take the risk of selecting low scented link (t1,t2) – Risk averse individuals: less severe problems take a more conservative strategy by moving to another web patch (t3, t4, t6) ACM Hypertext 20132 May 2013 22
  23. 23. Implications Challenging established conceptions • IFT: users leave a website when the scent of the current page is below the average of the pages visited • SR users give up after overcoming a number of problematic interactions • We have 2 thresholds: information scent and frustration threshold ACM Hypertext 20132 May 2013 23
  24. 24. Follow up 2 May 2013 24 Contact @markelvigo | markel.vigo@manchester.ac.uk Presentation DOI http://dx.doi.org/10.6084/m9.figshare.695073 Datasets http://wel-data.cs.manchester.ac.uk/investigations/2 24th ACM Conference on Hypertext and Social Media Hypertext 2013

×