{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T20:53:02Z","timestamp":1777668782261,"version":"3.51.4"},"reference-count":24,"publisher":"SAGE Publications","issue":"3","license":[{"start":{"date-parts":[[1999,9,1]],"date-time":"1999-09-01T00:00:00Z","timestamp":936144000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Hum Factors"],"published-print":{"date-parts":[[1999,9]]},"abstract":"<jats:p>\n                    Two experiments have investigated the effects of lag on discrete target-directed head movements in a virtual environment. Both the target and a head-slaved pointer (subjected to lag) were presented on a head-mounted display. Targetdirected head movements in the presence of a constant time lag were shown to obey Fitts' law (R\n                    <jats:sup>2<\/jats:sup>\n                    &lt; .93). A previously reported interaction between the effects of lag and the effects of index-of-difficulty on hand movement time could not be found in head movement time when the target width was kept constant. Further experiments suggested that there is a significant interaction between the effects of target width and lag but not between target distance and lag. A model predicting head movement strategy in the presence of lag is proposed to explain the experimental findings. This model predicts, and experiments verified, that for a target width from 1\u00b0 to 8\u00b0 and a target distance range of 2.5\u00b0 to 30\u00b0 , the effect of lag (up to 267 ms) on target-directed head movement is independent of target distance but dependent on target width. Actual or potential applications of this research include the design of virtual control panel and its layout in a Virtual Reality simulator.\n                  <\/jats:p>","DOI":"10.1518\/001872099779611067","type":"journal-article","created":{"date-parts":[[2007,1,20]],"date-time":"2007-01-20T10:29:16Z","timestamp":1169288956000},"page":"474-486","source":"Crossref","is-referenced-by-count":19,"title":["Target-Directed Head Movements in a Head-Coupled Virtual Environment: Predicting the Effects of Lags Using Fitts' Law"],"prefix":"10.1177","volume":"41","author":[{"given":"Richard H.Y.","family":"So","sequence":"first","affiliation":[{"name":"Hong Kong University of Science and Technology, Hong Kong"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Germen K.M.","family":"Chung","sequence":"additional","affiliation":[{"name":"Hong Kong University of Science and Technology, Hong Kong"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ravindra S.","family":"Goonetilleke","sequence":"additional","affiliation":[{"name":"Hong Kong University of Science and Technology, Hong Kong"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[1999,9,1]]},"reference":[{"key":"atypb1","doi-asserted-by":"publisher","DOI":"10.1177\/001872088903100606"},{"key":"atypb2","doi-asserted-by":"publisher","DOI":"10.1093\/oso\/9780195075557.001.0001"},{"key":"atypb3","doi-asserted-by":"crossref","unstructured":"Barnes, W. J. (1989, March). Tactical applications of the helmetmounted display in fighter aircraft. Proceedings of the SPIE Conference on Helmet-Mounted Displays (pp.149\u2013160). Bellingham, WA: The International Society for Optical Engineering.","DOI":"10.1117\/12.960910"},{"key":"atypb4","doi-asserted-by":"publisher","DOI":"10.1145\/229459.229468"},{"key":"atypb5","volume-title":"Engineering data compendium: Human perception and performance","author":"Boff, K. R.","year":"1988"},{"key":"atypb6","doi-asserted-by":"crossref","unstructured":"Eggleston, R. G. & Janson, W. P. (1997). Field of view on a direct manipulation task in a virtual environment. In Proceedings of the Human Factors and Ergonomics Society 44th Annual Meeting, pp. 1244\u20131249. Santa Monica, CA: Human Factors and Ergonomics Society.","DOI":"10.1177\/1071181397041002116"},{"key":"atypb7","doi-asserted-by":"publisher","DOI":"10.1109\/THFE.1965.6591253"},{"key":"atypb8","doi-asserted-by":"publisher","DOI":"10.1037\/h0045689"},{"key":"atypb9","volume-title":"Human performance","author":"Fitts, P. M.","year":"1967"},{"key":"atypb10","doi-asserted-by":"publisher","DOI":"10.1109\/TSMC.1976.5408778"},{"key":"atypb11","doi-asserted-by":"publisher","DOI":"10.1080\/00140139208967796"},{"key":"atypb12","doi-asserted-by":"publisher","DOI":"10.1080\/00222895.1985.10735338"},{"key":"atypb13","volume-title":"The science of virtual reality and virtual environments","author":"Kalawsky, R. S.","year":"1993"},{"key":"atypb14","doi-asserted-by":"publisher","DOI":"10.1080\/00140139208967804"},{"key":"atypb15","doi-asserted-by":"publisher","DOI":"10.1145\/169059.169431"},{"key":"atypb16","volume-title":"Bodyspace: Anthropometry, ergonomics, and design","author":"Pheasant, S.","year":"1986"},{"key":"atypb17","doi-asserted-by":"publisher","DOI":"10.1177\/001872089003200405"},{"key":"atypb18","doi-asserted-by":"crossref","unstructured":"Rogers, S. P., Spiker, V. A. & Fischer, S. C. (1997, April). Effects of system lag on head-tracked cursor control. In Proceedings of the SPIE Conference on Head-Mounted Displays II, (pp. 14\u201323). Bellingham, WA: The International Society for Optical Engineering.","DOI":"10.1117\/12.276644"},{"key":"atypb19","doi-asserted-by":"publisher","DOI":"10.1109\/THFE.1963.231283"},{"key":"atypb20","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1109\/TSMC.1979.4310186","volume":"9","author":"Starr, G. P.","year":"1979","journal-title":"IEEE Transactions on Systems, Man, and Cybernetics"},{"key":"atypb21","unstructured":"So, R. H. Y. & Griffin, M. J. (1993).\n                      Effect of lags on human performance with head-coupled simulators\n                      . Wright-Patterson Air Force Base, OH: Armstrong Laboratory. (NYIS Mo. AL\/CFTR-1990-0101)"},{"key":"atypb22","first-page":"74","volume-title":"Contemporary ergonomics","author":"So, R. H. Y.","year":"1995"},{"key":"atypb23","first-page":"103","volume-title":"Simulated and Virtual Realities: Elements of perception","author":"So, R. H. Y.","year":"1995"},{"key":"atypb24","doi-asserted-by":"publisher","DOI":"10.1109\/TSMC.1987.4309031"}],"container-title":["Human Factors: The Journal of the Human Factors and Ergonomics Society"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1518\/001872099779611067","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1518\/001872099779611067","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T07:51:09Z","timestamp":1777449069000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1518\/001872099779611067"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,9]]},"references-count":24,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1999,9]]}},"alternative-id":["10.1518\/001872099779611067"],"URL":"https:\/\/doi.org\/10.1518\/001872099779611067","relation":{},"ISSN":["0018-7208","1547-8181"],"issn-type":[{"value":"0018-7208","type":"print"},{"value":"1547-8181","type":"electronic"}],"subject":[],"published":{"date-parts":[[1999,9]]}}}