research-article

Public Access

Creating New Technologies for Companionable Agents to Support Isolated Older Adults

Authors:

Candace L. Sidner,

Timothy Bickmore,

Bahador Nooraie,

Mahni Shayganfar,

Laura VardoulakisAuthors Info & Claims

ACM Transactions on Interactive Intelligent Systems (TiiS), Volume 8, Issue 3

Article No.: 17, Pages 1 - 27

https://doi.org/10.1145/3213050

Published: 24 July 2018 Publication History

Abstract

This article reports on the development of capabilities for (on-screen) virtual agents and robots to support isolated older adults in their homes. A real-time architecture was developed to use a virtual agent or a robot interchangeably to interact via dialog and gesture with a human user. Users could interact with either agent on 12 different activities, some of which included on-screen games, and forms to complete. The article reports on a pre-study that guided the choice of interaction activities. A month-long study with 44 adults between the ages of 55 and 91 assessed differences in the use of the robot and virtual agent.

References

[1]

M. Argyle and M. Cook. 1976. Gaze and Mutual Gaze. Cambridge University Press.

[2]

M. Behrooz, C. Rich, and C. Sidner. 2014. On the sociability of a game-playing agent: a software framework and empirical study. In Proceedings of the 14th International Conference on Intelligent Virtual Agents. Springer. 40--53.

[3]

E. Berscheid, M. Snyder, and A. M. Omoto. 1989. The relationship closeness inventory: Assessing the closeness of interpersonal relationships. J. Pers. Soc. Psychol. 57, 5 (1989), 792.

[4]

T. Bickmore, L. Caruso, K. Clough-Gorr, and T. Heeren. 2005. “It’s just like you talk to a friend”: Relational agents for older adults. Interact. Comput. 17, 6 (Dec. 2005), 711--735.

Digital Library

[5]

T. Bickmore, D. Schulman, and L. Yin. 2010. Maintaining engagement in long-term interventions with relational agents. Int. J. Appl. Artif. Intell. 24, 6 (Jul. 2010), 648--666.

Digital Library

[6]

T. Bickmore, R. Silliman, K. Nelson, D. Cheng, M. Winter, L. Henaulat, and M. Paasche-Orlow. 2013. A randomized controlled trial of an automated exercise coach for older adults. J. Am. Geriat. Soc. 61, 10 (Sept. 2013), 1676--1683.

[7]

Jakob B. Bjorner and Diane M. Turner-Bowker. 2009. SF-36 and SF-12 health surveys. In Encyclopedia of Medical Decision Making, Vol. 2 Michael W. Kattan (Ed.). 1030--1036.

[8]

Robert N. Butler. 1964. The life review: An interpretation of reminiscence in the aged. In New Thoughts on Old Age. R. Kastenbaum (Ed.). Springer, Berlin. 65--70.

[9]

C. Chao, C. Lee, M. Begum, and A. Thomaz. 2011. Simon plays Simon says: The timing of turn-taking in an imitation game. In Proceedings of the International Symposium on Robot and Human Interactive Communication (RO-MAN’11). IEEE Press, New York, NY, 235--240.

[10]

Juan Fasola and Maja J. Matarić. 2013. A socially assistive robot exercise coach for the elderly. J. Hum.-Robot Interact. 2, 2 (2013), 3--32.

Digital Library

[11]

J. Fodor and M. Roubens. 1994. Fuzzy Preference Modeling and Multicriteria Decision Support. Springer, The Netherlands, 1994.

[12]

Maartje M. A. de Graaf, Somaya Ben Allouch, and Jan A. G. M. van Dijk. 2017. Long-term evaluation of a social robot in real homes. Interaction Studies 17, 3 (Jul 2017).

[13]

M. Granata, A. Chetouani, A. Tapus, P. Bidaud, and A. Dupourque. 2010. Voice and graphical-based interfaces for interaction with a robot dedicated to elderly and people with cognitive disorders. In Proceedings of the 19th IEEE International Symposium on Robot and Human Interactive Communication (RO-MAN’10). IEEE, 785--790.

[14]

Erico Guizzo. Robosoft unveils kompai robot to assist elderly, Disabled. IEEE Spectrum Online. (March 9, 2010). Retrieved February 1, 2017 from http://spectrum.ieee.org/automaton/robotics/medical-robots/robosoft-kompai-robot-assist-elderly-disabled.

[15]

S. Hanke, E. Sandner, C. Tsiourti, and A. Stainer-Hochgatterer. 2015. The technical specification and architecture of a virtual support partner. In Proceedings of the Workshop on Affective Interaction with Avatars, in Conjunction with the European Conference on Ambient Intelligence (AmI’15).

[16]

D. Hasegawa, J. Cassell, and K. Araki. 2010. The role of embodiment and perspective in direction-giving systems. Dialog with robots: AAAI Fall Symposium. 2010. Retrieved October 25, 2017 from https://www.aaai.org/ocs/index.php/FSS/FSS10/paper/view/2186.

[17]

A. Holroyd, C. Rich, C. Sidner, and B. Ponsler. 2011. Generating connection events for human-robot collaboration. In Proceedings of the 20th IEEE International Symposium on Robot and Human Interactive Communication (ROMAN’11). IEEE Press, 241--246.

[18]

A. Holroyd and C. Rich. 2012. Using the behavior markup language for human-robot interaction. In Proceedings of the ACM Conference on Human--Robot Interaction. ACM Press, New York, NY, 147--148.

Digital Library

[19]

C. Huijnen, A. Badii, H. van den Heuvel, P. Caleb-Solly, and D. Thiemert. 2011. Maybe it becomes a buddy, but do not call it a robot - seamless cooperation between companion robotics and smart homes. In Proceedings of the 2nd International Joint Conference on Ambient Intelligence (AmI’11). Springer, New York, NY, 324--329.

Digital Library

[20]

D. O. Johnson, R. H. Cuijpers, J. F. Juola, E. Torta, M. Simonov, A. Frisiello, M. Bazzani, W. Yan, C. Weber, S. Wermter, N. Meins, J. Oberzaucher, P. Panek, G. Edelmayer, P. Mayer, and C. Beck. 2014. Socially assistive robots: A comprehensive approach to extending independent living. Int. J. Soc. Robot. 6, 2 (Apr.’14). 195--211.

[21]

Adam Kendon. 1967. Some functions of gaze direction in two person interaction. Acta Psychol. 26 (1967), 22--63.

[22]

C. Kidd and C. Breazeal. 2004. Effect of a robot on user perceptions. In Proceeings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS’04), Vol. 4. IEEE Press, New York, NY, 3559--3564.

[23]

C. D. Kidd and C. Breazeal. 2008. Robots at home: Understanding long-term human-robot interaction. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS’08). IEEE Press, Los Alamitos, CA, 3230--3235.

[24]

T. Klamer, S. Ben Allouch, and D. Heylen. 2010. “Adventures of harvey”: Use, acceptance of and relationship building with a social robot in a domestic environment. In Proceedings of the 3rd International Conference on Human--Robot Personal Relationships (HRPR’10), Springer, Berlin, 74--82.

[25]

B. Löwe, K. Kroenke, and K. Gräfe. 2005. Detecting and monitoring depression with a two-item questionnaire (PHQ-2). J. Psychosomat. Res. 58, 2 (2005), 163--171.

[26]

S. Lyubomirsky and H. Lepper. 1999. A measure of subjective happiness: Preliminary reliability and construct validation. Soc. Indic. Res. 46, 2 (1999), 137--155.

[27]

D. Maciuszek, J. Åberg, and N. Shahmehri. 2005. Evaluation and refinement of a design framework for generating dependable virtual companions for later life. In Proceedings of the 3rd International Conference on Smart homes and Health Telematics: From Smart Homes to Smart Care (ICOST’05), IOS Press, Amsterdam, The Netherlands, 50--64.

[28]

Marcus Mast, Michael Burmester, Katja Krüger, Sascha Fatikow, Georg Arbeiter, Birgit Graf, Gernot Kronreif, Lucia Pigini, David Facal, and Renxi Qiu. 2012. User-centered design of a dynamic-autonomy remote interaction concept for manipulation-capable robots to assist elderly people in the home. J. Hum.-Robot Interact. 1, 1 (2012).

Digital Library

[29]

Miraculous Life. 2013. Retrieved February 1, 2017 from http://www.miraculous-life.eu/index.php.

[30]

M. Nani, P. Caleb-Solly, S. Dogramadgi, C. Fear, and H. van den Heuvel. 2010. MOBISERV: An integrated intelligent home environment for the provision of health, nutrition and mobility services to the elderly. In Proceedings of the 4th Companion Robotics Workshop.

[31]

N. R. Nicholson. A review of social isolation: An important but underassessed condition in older adults. J. Primary Prevent. 33, 2--3 (Jun. 2012), 137--152.

[32]

J. S. Norbeck, A. M. Lindsey, and V. L. Carrieri. 1983. Further development of the norbeck social support questionnaire: Normative data and validity testing. Nursing Research 32, 1 (1983), 4--9.

[33]

B. Nooraei, C. Rich, and C. Sidner. 2014. A real-time architecture for embodied conversational agents: Beyond turn-taking. In Proceedings of the 7th International Conference on Advances in Computer--Human Interactions.

[34]

Hugo Pinto, Yorick Wilks, Roberta Catizone, and Alexiei Dingli. 2008. The senior companion multiagent dialogue system. In Proceedings of the 7th International Joint Conference on Autonomous Agents and Multiagent Systems. 1245--1248.

Digital Library

[35]

L. E. Powell and A. M. Myers. 1995. The activities-specific balance confidence (ABC) Scale. J. Gerontol. A Biol. Sci. Med. Sci. 50A, 1 (1995), M28--M34.

[36]

M. Reblin and B. N. Uchino. 2008. Social and emotional support and its implication for health. Curr. Opin. Psychiatr. 21, 2 (Mar. 2008), 201--205.

[37]

Reeti, a Smart Compagnon, a Multimedia Tool. 2017. Retrieved March 1, 2017 from http://www.reeti.fr/index.php/en/detailen.

[38]

P. H. Robert, A. Konig, H. Amieva, S. Andrieu, F. Bremond, R. Bullock, M. Ceccaldi, B. Dubois, S. Gauthier, P. A. Kenisgberg, S. Nave, J. M. Orgogozo, J. Piano, M. Benoit, J. Touchon, B. Vellas, J. Yesavage, and V. Manera. Recommendations for the use of Serious Games in people with Alzheimer’s Disease, related disorders and frailty. Front. Aging Neurosci. 6, 54, (Mar. 24, 2014).

[39]

L. Ring, L. Shi, K. Totzke, and T. Bickmore. Social support agents for older adults: Longitudinal affective computing in the home. J. Multimodal User Interfaces 9, 1 (2015), 79--88.

[40]

C. Rich and C. Sidner. 1999. Collagen: A collaboration manager for software interface agents. User Model. User-Adapt. Interact. 8, 3/4 (Sep. 1998), 315--350.

Digital Library

[41]

C. Rich, C. Sidner, and N. Lesh. 2001. Collagen: Applying collaborative discourse theory to human-computer interaction. AI Mag. 22, 4 (Winter 2001), 15--25.

Digital Library

[42]

C. Rich. 2009. Building task-based user interfaces with ANSI/CEA-2018. IEEE Comput. 42, 8 (Aug. 2009), 20--27.

Digital Library

[43]

C. Rich, B. Ponsler, A. Holroyd, and C. Sidner, 2010. Recognizing engagement in human-robot interaction. In Proceedings of the 5th ACM/IEEE International Conference on Human-Robot Interaction. IEEE Press, Los Alamitos, CA. 375--382.

Digital Library

[44]

C. Rich and C. L. Sidner. 2012. Using collaborative discourse theory to partially automate dialogue tree authoring. In Proceedings of the 12th International Conference on Intelligent Virtual Agents (IVA’12), Springer, Berlin, 327--340.

Digital Library

[45]

D. Russell and L. Peplau. 1980. The revised UCLA loneliness scale: Concurrent and discriminant validity evidence. J. Pers. Soc. Psychol. 39 (Sep. 1980), 472--480.

[46]

S. Sabanovic, T. Bennett, W. Chang, and L. Huber. 2013. PARO robot affects diverse interaction modalities in group sensory therapy for older adults with dementia. In Proceedings of the IEEE International Conference on Rehabilitation Robotics (ICORR’13). IEEE Press, Los Alamitos, CA. 1--6.

[47]

Emanuel A. Schegloff and Harvey Sacks. 1973. Opening up closings. Semiotica 8, 4 (Nov. 2009). 289--327.

[48]

A. Seiderer, S. Hammer, E. Andre, M. Mayr, and T. Rist. 2015. Exploring digital image frames for lifestyle intervention to improve well-being of older adults. In Proceedings of the 5th International Conference on Digital Health (DH’15). ACM New York, NY 71--78.

Digital Library

[49]

C. L. Sidner, C. Lee, C. Kidd, N. Lesh, and C. Rich. 2005. Explorations in engagement for humans and robots. Artif. Intell. 166, 1--2 (Aug. 2005), 140--164.

Digital Library

[50]

C. L. Sidner, C. Rich, M. Shayganfar, T. Bickmore, L. Ring, and Z. Zhang. 2015. A robotic companion for social support of isolated older adults. In Extended Abstracts, Proceedings of the 10th Annual ACM/IEEE International Conference on Human-Robot Interaction Extended Abstracts (HRI’15), ACM Press, New York, NY. 289. Video at: https://www.youtube.com/watch?v=HngGcvEuB60, retrieved January 1, 2017.

Digital Library

[51]

Andrew Steptoe, Aparna Shankar, Panayotes Demakakos, and Jane Wardle. Social isolation, loneliness and all-cause mortality in older men and women. Proc. Natl. Acad. Sci. U.S.A. 110, 15 (Apr. 9, 2013), 5797--5801.

[52]

Paul D. Thompson, Ross Arena, Deborah Riebe, and Linda Pescatello. 2013. ACSMs new preparticipation health screening recommendations from ACSMs guidelines for exercise testing and prescription, ninth edition. J Curr. Sports Med. Rep. 12, 4 (Jul./Aug. 2013), 215--217.

[53]

Christiana Tsiourti, Emilie Joly, Cindy Wings, and Katarzyna Wac. Virtual assistive companions for older adults: Qualitative field study and design implication. In Proceedings of the 8th International Conference on Pervasive Computing Technologies for Healthcare. 57--64.

Digital Library

[54]

L. Pfeifer Vardoulakis, L. Ring, B. Barry, C. Sidner, and T. Bickmore. 2012. Designing relational agents as long term social companions for older adults. In Proceedings of the 12th International Conference on Intelligent Virtual Agents (IVA’12). Springer-Verlag, Berlin, 289--302.

Digital Library

[55]

H. Vilhjálmsson, N. Cantelmo, J. Cassell, N. E. Chafai, M. Kipp, S. Kopp, M. Mancini, S. Marsella, A. N. Marshall, C. Pelachaud, Z. Ruttkay, K. R. Thórisson, H. van Welbergen, and R. J. van der Werf. 2007. The behavior markup language: recent developments and challenges. In Proceedings of the Conference on Intelligent Virtual Agents (IVA’07). Lecture Notes in Computer Science, Vol. 4722. C. Pelachaud, J. C. Martin, E. André, G. Chollet, K. Karpouzis, and D. Pelé (eds). Springer, Berlin.

[56]

K. Wada, T. Shibata, T. Saito, and K. Tanie. 2003. Effects of robot assisted activity to elderly people who stay at a health service facility for the aged. In Proceedings of the 2003 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS’03), Vol. 3. IEEE Press, Los Alamitos, CA, 2847--2853.

[57]

J. Wainer, D. Feil-Seifer, D. A. Shell, and M. J. Matarić. 2007. Embodiment and human-robot interaction: A task-based perspective. Proceedings, 16th IEEE International Workshop on Robot and Human Interactive Communication (RO-MAN 2007), IEEE Press (2007), 872--877.

[58]

K. Windle, F. Francis and C. Coomber. 2011. Preventing Loneliness and Social Isolation: Interventions and Outcomes. (October 2011). Retrieved October 25, 2017 from https://www.scie.org.uk/publications/briefings/briefing39/.

[59]

J. Wrobel, Y. Wu, H. Kerhervé, L. Kamali, A. Rigaud, C. Jost, B. Le Pévédic, and D. Duhaut. 2013. Effect of agent embodiment on the elder user enjoyment of a game. In Proceedings of the 6th International Conference on Advances in Computer-Human Interactions (ACHI’13).

[60]

R. Yaghoubzadeh, M. Kramer, K. Pitsch, and S. Kopp. 2013. Virtual agents as daily assistants for elderly or cognitively impaired people, studies on acceptance and interaction feasibility. In 13th International Conference on Intelligent Virtual Agents and Intelligent Virtual Agents (IVA’13), Spring-Verlag, Berlin. 79--91.

[61]

V. Yngve. 1970. On getting a word in edgewise. In Papers from the 6th Regional Meeting of the Chicago Linguistics Society. University of Chicago, Department of Linguistics, 567--578.

Cited By

Jabir ALin XMartinengo LSharp GTheng YTudor Car L(2024)Attrition in Conversational Agent–Delivered Mental Health Interventions: Systematic Review and Meta-AnalysisJournal of Medical Internet Research10.2196/4816826(e48168)Online publication date: 27-Feb-2024
https://doi.org/10.2196/48168
Palmier CRigaud AOgawa TWieching RDacunha SBarbarossa FStara VBevilacqua RPino M(2024)Identification of Ethical Issues and Practice Recommendations Regarding the Use of Robotic Coaching Solutions for Older Adults: Narrative ReviewJournal of Medical Internet Research10.2196/4812626(e48126)Online publication date: 18-Jun-2024
https://doi.org/10.2196/48126
Wong NJeong SReddy MStamatis CLattie EJacobs M(2024)Voice Assistants for Mental Health Services: Designing Dialogues with Homebound Older AdultsProceedings of the 2024 ACM Designing Interactive Systems Conference10.1145/3643834.3661536(844-858)Online publication date: 1-Jul-2024
https://dl.acm.org/doi/10.1145/3643834.3661536
Show More Cited By

Index Terms

Creating New Technologies for Companionable Agents to Support Isolated Older Adults
1. Computing methodologies
  1. Artificial intelligence
    1. Distributed artificial intelligence
      1. Intelligent agents
    2. Knowledge representation and reasoning
      1. Cognitive robotics
2. Human-centered computing
  1. Human computer interaction (HCI)
    1. HCI design and evaluation methods

Recommendations

Persuasive dialogue for older adults: promoting and encouraging social interaction
CHI EA '13: CHI '13 Extended Abstracts on Human Factors in Computing Systems

We describe a persuasive dialogue component for promoting and encouraging social interaction for older adults. In order to identify effective persuasive strategies we conducted an interview study with formal carers for older adults. From the results of ...
Recruiting Older Adults in the Wild: Reflections on Challenges and Lessons Learned from Research Experience
PervasiveHealth '18: Proceedings of the 12th EAI International Conference on Pervasive Computing Technologies for Healthcare

It is important to understand the older adults prior to the design process. The understanding can better facilitate design conversations between the researchers and the older adults. In this paper, we discussed our experiences of building a relationship ...
Home robotic devices for older adults: Opportunities and concerns
Abstract
Robotic devices for older adults are becoming a reality. New robots are being introduced for the growing subpopulation of healthy older adults, with an emphasis on supporting the positive aspects of aging. In order to inform the design ...
Highlights
- Older adults' attitudes and emotional reactions toward robotic devices were evaluated.

Comments

Information & Contributors

Information

Published In

cover image ACM Transactions on Interactive Intelligent Systems

ACM Transactions on Interactive Intelligent Systems Volume 8, Issue 3

September 2018

235 pages

ISSN:2160-6455

EISSN:2160-6463

DOI:10.1145/3236465

Editor:
Michelle X. Zhou
Juji, Inc., USA

Issue’s Table of Contents

Copyright © 2018 ACM.

Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected].

Publisher

Association for Computing Machinery

New York, NY, United States

Publication History

Published: 24 July 2018

Accepted: 01 March 2018

Revised: 01 February 2018

Received: 01 April 2017

Published in TIIS Volume 8, Issue 3

Permissions

Request permissions for this article.

Request Permissions

Check for updates

Author Tags

Qualifiers

Research-article
Research
Refereed

Funding Sources

National Science Foundation

Contributors

Other Metrics

View Article Metrics

Bibliometrics & Citations

Bibliometrics

Article Metrics

57
Total Citations
View Citations
1,631
Total Downloads

Downloads (Last 12 months)293
Downloads (Last 6 weeks)32

Reflects downloads up to 25 Dec 2024

Other Metrics

View Author Metrics

Citations

Cited By

Jabir ALin XMartinengo LSharp GTheng YTudor Car L(2024)Attrition in Conversational Agent–Delivered Mental Health Interventions: Systematic Review and Meta-AnalysisJournal of Medical Internet Research10.2196/4816826(e48168)Online publication date: 27-Feb-2024
https://doi.org/10.2196/48168
Palmier CRigaud AOgawa TWieching RDacunha SBarbarossa FStara VBevilacqua RPino M(2024)Identification of Ethical Issues and Practice Recommendations Regarding the Use of Robotic Coaching Solutions for Older Adults: Narrative ReviewJournal of Medical Internet Research10.2196/4812626(e48126)Online publication date: 18-Jun-2024
https://doi.org/10.2196/48126
Wong NJeong SReddy MStamatis CLattie EJacobs M(2024)Voice Assistants for Mental Health Services: Designing Dialogues with Homebound Older AdultsProceedings of the 2024 ACM Designing Interactive Systems Conference10.1145/3643834.3661536(844-858)Online publication date: 1-Jul-2024
https://dl.acm.org/doi/10.1145/3643834.3661536
Zhang YLuo LWang X(2024)Aging with robots: A brief review on eldercare automationInterdisciplinary Nursing Research10.1097/NR9.00000000000000523:1(49-56)Online publication date: Mar-2024
https://doi.org/10.1097/NR9.0000000000000052
Wang YZhou YChen XFang H(2024)Operational Performance and Subjective Preferences of Elderly Users in Intelligent Interactive Interfaces: A Systematic ReviewInternational Journal of Human–Computer Interaction10.1080/10447318.2024.2352226(1-15)Online publication date: 20-May-2024
https://doi.org/10.1080/10447318.2024.2352226
Woo JShidara KAchard CTanaka HNakamura SPelachaud C(2024)Adaptive virtual agent: Design and evaluation for real-time human-agent interactionInternational Journal of Human-Computer Studies10.1016/j.ijhcs.2024.103321190(103321)Online publication date: Oct-2024
https://doi.org/10.1016/j.ijhcs.2024.103321
Tan XWilson ITay PWin PSong CWee S(2024)Mapping of Technological Strategies for Reducing Social Isolation in Homebound Older Adults: A Scoping ReviewArchives of Gerontology and Geriatrics10.1016/j.archger.2024.105478(105478)Online publication date: May-2024
https://doi.org/10.1016/j.archger.2024.105478
McTear MJokinen KAlam MSaleem QNapolitano GSzczepaniak FHariz MChollet GLohr CBoudy JAzimi ZRoelen SWieching R(2023)Interaction with a Virtual Coach for Active and Healthy AgeingSensors10.3390/s2305274823:5(2748)Online publication date: 2-Mar-2023
https://doi.org/10.3390/s23052748
Rodríguez-Martínez AAmezcua-Aguilar TCortés-Moreno JJiménez-Delgado J(2023)Qualitative Analysis of Conversational Chatbots to Alleviate Loneliness in Older Adults as a Strategy for Emotional HealthHealthcare10.3390/healthcare1201006212:1(62)Online publication date: 27-Dec-2023
https://doi.org/10.3390/healthcare12010062
El Kamali MAngelini LLalanne DAbou Khaled OMugellini E(2023)Older adults' perspectives on multimodal interaction with a conversational virtual coachFrontiers in Computer Science10.3389/fcomp.2023.11258955Online publication date: 7-Nov-2023
https://doi.org/10.3389/fcomp.2023.1125895
Show More Cited By

View Options

View options

PDF

View or Download as a PDF file.

eReader

View online with eReader.

Login options

Check if you have access through your login credentials or your institution to get full access on this article.

Full Access

Get this Article

Media

Figures

Other

Tables

View Issue’s Table of Contents