{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T05:02:14Z","timestamp":1780635734386,"version":"3.54.1"},"reference-count":27,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2020,5,27]],"date-time":"2020-05-27T00:00:00Z","timestamp":1590537600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency","doi-asserted-by":"publisher","award":["JPMJCR18A1"],"award-info":[{"award-number":["JPMJCR18A1"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Touch plays a crucial role in humans\u2019 nonverbal social and affective communication. It then comes as no surprise to observe a considerable effort that has been placed on devising methodologies for automated touch classification. For instance, such an ability allows for the use of smart touch sensors in such real-life application domains as socially-assistive robots and embodied telecommunication. In fact, touch classification literature represents an undeniably progressive result. However, these results are limited in two important ways. First, they are mostly based on overall (i.e., average) accuracy of different classifiers. As a result, they fall short in providing an insight on performance of these approaches as per different types of touch. Second, they do not consider the same type of touch with different level of strength (e.g., gentle versus strong touch). This is certainly an important factor that deserves investigating since the intensity of a touch can utterly transform its meaning (e.g., from an affectionate gesture to a sign of punishment). The current study provides a preliminary investigation of these shortcomings by considering the accuracy of a number of classifiers for both, within- (i.e., same type of touch with differing strengths) and between-touch (i.e., different types of touch) classifications. Our results help verify the strength and shortcoming of different machine learning algorithms for touch classification. They also highlight some of the challenges whose solution concepts can pave the path for integration of touch sensors in such application domains as human\u2013robot interaction (HRI).<\/jats:p>","DOI":"10.3390\/s20113033","type":"journal-article","created":{"date-parts":[[2020,5,28]],"date-time":"2020-05-28T12:36:58Z","timestamp":1590669418000},"page":"3033","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Gentle Versus Strong Touch Classification: Preliminary Results, Challenges, and Potentials"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0854-0354","authenticated-orcid":false,"given":"Soheil","family":"Keshmiri","sequence":"first","affiliation":[{"name":"Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0237, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masahiro","family":"Shiomi","sequence":"additional","affiliation":[{"name":"Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0237, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1511-9525","authenticated-orcid":false,"given":"Hidenobu","family":"Sumioka","sequence":"additional","affiliation":[{"name":"Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0237, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takashi","family":"Minato","sequence":"additional","affiliation":[{"name":"Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0237, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiroshi","family":"Ishiguro","sequence":"additional","affiliation":[{"name":"Advanced Telecommunications Research Institute International (ATR), Kyoto 619-0237, Japan"},{"name":"Graduate School of Engineering Science, Osaka University, Osaka 565-0871, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5","DOI":"10.3200\/MONO.132.1.5-94","article-title":"The communicative functions of touch in humans, nonhuman primates, and rats: A review and synthesis of the empirical research","volume":"132","author":"Hertenstein","year":"2006","journal-title":"Genet. 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