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Nozawa thesis


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Nozawa thesis

  1. 1. 1University of Aizu, Graduation Thesis. March, 2012 s1170033AbstractUser manuals for physical performance help usunderstand how a task is actually performed in a 3-dspace. Literature on spatial informationcomprehension is scant on the topic related toidentifying factors which leads spatial comprehensionof physical tasks. The literature on mental imageryand rotation has been discussed in this context of anexperiment where body rotations, object height andaction combinations have been studied to understandhow mental rotation tasks are performed. Theexperiment reported in this thesis focused onmatching body rotation-action-object heightcombinations shown from body height with overheadimages. Two types of activities were used: holding abat and swinging a bat. Five body rotations from fullfront to back views were used with the bat being heldat chest and waist height. Results show that canonicalviewpoints and angles across the display plane aresomewhat preferred, although accuracy with non-canonical viewpoints and angles into the displayplane were also high. The study thus goes on to showthat with more practice and time spent, mentalrotation tasks could be better performed.1 IntroductionMental imagery is an experience and an importantaspect of our general understanding of how differentobjects functions in space without direct visualization[1]. In a complex spatial world, mental imagery canpresent some complex cases of comprehensioninvolving mental rotation. Mental rotation is theability to rotate two-dimensional and three-dimensional objects in space but as an internalrepresentation of the mind. It is basically about howthe brain moves objects in the physical space in amanner that helps with spatial understanding andintelligence (including structural and functionalattributes) of objects in space [2][3][4].Research in psychology has provided enoughliterature demonstrating how people develop andcustomize mental models and perform mentalrotation towards performing procedural actions inspace. This is where technical illustrations canactually help develop guidelines in a way that mighthelp users perform mental rotations in a predefined orexpected sequence. This leads us to the question ofwhy we need technical illustrations forcommunicating visually complex information.Technical illustration is the use of illustration tovisually communicate information of complexinformation [5]. The main purpose of any technicalillustration is to create expressive images, which hasmeaning to the human senses and observer. Theaccuracy of technical illustrations in terms ofdimensions and proportions help readers with visualcomprehension of the structural and functionalaspects of a given object in space. Naturally, this isvery important for showing body positions.In this context, one must introduce the concept ofkinesthetic learning. It is a learning style whereby theperformer learns by carrying out a physical activity inactual physical space, rather than thinking andconjecturing about a physical action. The theory ofmultiple intelligence by Gardner [6] has mentionedkinesthetic learning. Kinesthetic learners are thoughtto be the ones who prefer to physically try out andperform the action involving their own bodilyexperience.Technical illustrations are designed to act as visualaids that help replicate physical actions in a wayintended by instructors of the act. Technicalillustration show actions from the point of view ofperformers, especially if performers’ bodies arerequired to be positioned a particular way to performactions. One can choose to understand complexinformation by using technical illustrations as an aid.2 Review of the Literature2.1 OverviewThe technical communication literature is not veryrich with studies other than by Krull et al., (2001;2003; 2004); (Szlichcinski, 1980); (Heiser andTversky, 2002) and few others, focusing primarily oncomprehension of procedural illustrations, and lessfor body positions in space [7][8][9][10][11].Traditionally, studies of mental imagery and rotationin experimental psychology have addressed this issueof object positions in space, but for comprehendingEfficacy of Technical Illustrations in a TechnicalCommunication EnvironmentMasato Nozawa s1170033 Supervised by Prof. Debopriyo Roy
  2. 2. 2University of Aizu, Graduation Thesis. March, 2012 s1170033human ability to perform mental rotation tasks inspace. This review of the literature is designed toexplain two major factors that might helpcomprehend physical actions and performing mentalrotation in a 3-d environment.● How do perception of depth and body/object-centered viewpoints influence comprehension ofphysical actions in a 3-d space?● How do motor skills and learning influence theway we design technical illustrations?Such understanding will help us comprehend what ittakes to design technical illustrations of physicalactions performed in a 3-d environment. What factorsshould technical illustrators consider for designinguser actions in space?2.2 PERCEPTION OF DEPTH 2-DTECHNICAL ILLUSTRATIONThere is extensive research done by Krull et al.,(2004) with the suggestion that graphics for physicaltasks need to take into account the needs of users whowill carry out actions in a physical environment [9].Research suggests that graphics need to show tasksfrom the users viewpoint, and need to make clearhow tools are to be used and the direction in whichactions are to be exerted. The paper provides somesample graphic design guidelines.Technical illustrations are useful only when readersare actually able to use their vision systems whenperforming tasks in the three dimensional space [5].Readers might scan through physical illustrationsshowing physical actions and use one type of visionsystem primarily for object identification purposes,while the other type of vision system could be usedfor orienting their bodies in space [8]. However,people are often able to comprehend well the distancebetween objects or body parts across the displayplane where the space between objects is visible.Contrarily, people find it relatively difficult to be ableto judge object positions when distances are to bejudged into the display plane [8].The problem is that while showing different variantsof body positions and physical actions as in sports,people often perceive positions, objects, movements,and forces along the line of sight into the displayplane, thereby obscuring the vision necessary tocomprehend or copy the action, exactly as it shouldbe executed.Research suggests that monocular vision dominatesbinocular vision in experiencing depth from 2Dpictures and speculated that binocular vision did notdevelop as a separate visual system but as an add-onto monocular vision [12]. Hochberg (1978) suggestedthat readers of 2-D illustrations on print or electronicmedia have only monocular vision to help theminterpret what they see [13]. Krull concluded thatmonocular cues reduces depth perception for 2-Dillustrations, thereby making interpretation moredifficult, and situates the choice of illustration’sperspective (body-centered vs. object-centered) as acentral consideration. Depth perception arises from avariety of depth cues. These are typically classifiedinto binocular cues that require input from both eyesand monocular cues that require the input from justone eye [14].So, an optimal illustration should technically alwayshelp readers see the maximum viewpoints availablein the scene, and show objects in a way such thatalmost no parts of the body in business is obscured ina way that handicaps the possible understanding andexecution of the task. This is what we call an object-centered view where objects are placed across thedisplay plane.2.3 USER-CENTERED VS.OBJECT-CENTEREDPERSPECTIVEAn illustration with an object-centered point of viewpositions objects across a display plane. Thisviewpoint, which could also be called a spectator’sview, allows objects to be placed so as to directviewers’ attention without obscuring important partsof objects [6].When we have to show a man pushing a cart, shouldwe show the scene where we see the back of the manpushing the cart? Although it goes well with the user-centered perspective, the cart will be obscured fromdirect viewing; neither would it be possible to gaugethe hand placement as to replicate exactly how thecart is being pushed. However, if a 1/3rd front or a1/3rd side vision is shown, at a waist length, it mightbe a lot easier to see most of the body and parts of thecart, including the hand placement of the manpushing the cart. Research by Heiser and Tversky(2002) with a furniture assembly task andSzlichcinski (1979; 1980) with hand positionssupported the efficacy of partially rotated objects ascompared to objects shown head-on, or shown withfull back [11][10].Psychological research [8] has concurred thatcanonical views showing two-dimensionalrepresentations of physical actions that are held in athree dimensional world are best represented whenillustrations are shown with objects in a three-quarterview from slightly below the camera position.
  3. 3. 3University of Aizu, Graduation Thesis. March, 2012 s1170033Although canonical views (slightly rotated viewpointto show maximum angles) are always preferred,when it comes to replicating tasks, the choicebetween a spectator’s viewpoint (seeing the action asan observer and not as a doer) and object-centeredviewpoint (seeing the action as a doer and not as anobserver) is rather obscure and more context-driven.If the question is to judge the distance between legswhen pushing a heavy cart, then a complete side viewmight be the most preferred option. However, if weneed to see the grip and arm movements (stretching)when pushing the cart, both side and zoomed-in frontviews might both be effective. This is important tounderstand because there are individual differences inthe way people prioritize objects in space vis-a-visthe orientation of their bodies in space and withdifferent interpretations of visual information [15]and with different performance levels on the task [16].2.4 UNDERSTANDING MOTORSKILLS FOR TECHNICALILLUSTRATIONS DESIGNWhile designing illustrations of physical actions in auser manual, technical illustrators should considertwo important things.●How is motor learning and performancedeveloped?● What are the best possible strategies for drawingtechnical illustrations (for different tasks) such that ithelps readers understand the physical actions, notonly what needs to be accomplished, but exactly howit needs to be done?Skills classified by task: A specific task, based onspecific skills could be classified in terms of howwell defined is the movement in a discrete, serial andcontinuous continuum.Skills classified by Cognitive Elements: Whilenetting the ball in a basketball game, there should becognitive strategies deciding on the precise nature ofjump and the throw (how much to jump and thedistance to throw). Perfecting the jump and throw to acertain level of efficiency is recognition of fine motorskill, and the strategy behind such efficiency iscognitive skill, and the combination leads to theconstant adaptation needed to reach a certain level ofefficiency.Skills Classified by Environmental Factors: Withmore environmental conditions and relatedunpredictability, the levels of cognitive skills mighthave more impact [17]. For example, when playingbaseball, how to swing the bat to hit the ball when theball swings in the air due to windy conditions is avalid consideration.3 MAJOR RESEARCH QUESTIONAND HYPOTHESESWhat might be the most optimal viewpoint towardscomprehending a two-dimensional illustrationshowing physical actions in a three-dimensionalspace?Hypothesis:● Objects shown from a performer’s point of viewshould be easier to understand.● Illustrations showing more angles across thedisplay plane might be easier to understand.● Levels of comprehension based on a two-dimensional illustration should differ based onwhether the objects are shown at or below the cameraposition.The purpose of this experiment as designed for thereported study is not to measure motor skills andperformance, but to identify it as a factor influencingperformance and learning, and most importantly toexplore the extent to which readers are able tocomprehend illustrations when demonstrated in aprint media from different perspectives and depthperceptions.Sample and Context: Forty-one students who arenon-native speakers of English (native Japanesespeakers) participated in this study.ProcedureThe experiment aims to understand how commonpeople understand images and relates them to imagesshown from different perspectives and camerapositions. We asked test subjects to evaluate bodyimages via matching tasks and asked them to ratetheir confidence in their choices.4 Method41 subjects took part in the experiment and eachsubject rated 40 image types, divided into two blocksof 20 each. As part of its robust design, theexperiment considered two sets of images. For theexperiment, we generated images of body positionsfor two kind activities: a man holding a bat and a manhitting with a bat. The purpose for using two differenttypes of objects relates to the exploration of whetherobject types influence how decisions about depthperceptions and display planes and viewpoints(object-centered or performer-centered) are made.This paper only discusses the results generated fromthe image set related to the man with the bat. The
  4. 4. 4University of Aizu, Graduation Thesis. March, 2012 s1170033other set (man with ball) has been discussed as part ofanother paper.Each participant was handed out two different sets aspart of an in-class graded assignment, with each sethaving 20 test sheets. Each participant was firsthanded out an instruction sheet in Japanese, and theywere orally explained in Japanese as to what isexpected of them from the experiment.The volunteers explained to them the purpose ofthe experiment, what it aims to achieve and how eachparticipant should approach the test. At that point, theparticipants were allowed to ask questions related tothe experiment, and voice any question or concern.The volunteers were also available throughout theexperiment to answer queries related to theexperiment. There was no time limit set for theparticipants to complete the experiment, but theywere expected to complete their responses within 90minutes. However, they were allowed to retain theanswer sheet with them until the next class meetingexactly a week later. There were two reasons whythere was no time limit maintained.(1) Students were allowed to think and re-thinkabout illustrations and were allowed to change theirresponses if they wanted to.(2) Students had to complete a series of questionsrelated to the experiment in Moodle as a gradedassignment, and retaining the test sheets andreferring back to those while answering thequestions in Moodle were naturally thought of asmore enriching.In each test sheet, participants were asked to circlethe correct choice. Each of the three options weredemonstrated as Picture A, B and C. They also wenton report their second best choice for each test sheetand also their levels of confidence for each response.Instruments:Using a computer program called POSER FigureArtist that sustains accurate three-dimensionalrelationships among body parts, the experimenterproduced variations of viewpoints and body positions.Each position included two heights for each activity:Chest and Waist. The man-with-bat-holding is shownas holding a bat centered in front of chest or waist withthe hands gripping the bat from both sides. The man-with-bat-throwing version shows hitting with bat at thechest or waist height. These action gestures werecaptured for five positions where the body moves withthe camera position remaining constant: Front - 0degrees (the man holding/throwing the ball and facingthe camera head on), 1/3 Side - 30 degrees, Side - 90degrees, 1/3 Back - 120 degrees, Back - 180 degrees.For all these images, the camera was positionedslightly above the waist height.Each set had five images and there were 4 sets in total.Every set was rotated in five angles as mentionedbefore. The first set showed a man holding a bat atchest height; the second set showed hitting at chestheight. Two other sets showed a man holding andhitting with a bat at waist height respectively.Once these images were generated, the camera wasthen positioned to capture images from the top for theabove-mentioned sets. A matching top image wasgenerated for each image generated from the setsabove, with a displacement along the y and z-axis toposition the camera exactly on top of the head. Each ofthe images generated for the 4 sets were tested to seewhether readers could identify the same when shownfrom the top. Each test sheet had an image from theabove sets, with three top views out of which only onetop view correctly represents the view shown fromslightly over the waist height. Each test sheet had threequestions and question 1 and 3 were answered in aLikert scale.1 Identify the most appropriate picture shown from thetop that matches the picture shown from the waistheight. (Three options provided).2 Which illustration shown from the top stands thesecond best?3 How confident are you about your response?Findings:A comprehensive review of data allows us to seethat there is some significant difference between the 20different body position-height-action combinationsthat were used for this analysis. Subsequent analysisrevealed whether the difference in the mean values ofaccuracy between body positions, as has beendiscussed in the next paragraph is statisticallysignificant.Data shows relatively highest mean values for manholding bat at chest height for 1/3rd side rotation at .93(meaning 93% of the participants completed thematching task accurately), holding waist 1/3rdback,holding waist back and front at over .90 mean score.Only one score from hitting category, hitting waistback rotation is marked at .93. Interestingly, almost allthe highest levels of accuracy for any given matchingtask are recorded for holding bat positions; with hittingpositions for any angle (except hitting waist backrotation) have lower levels of accuracy.
  5. 5. 5University of Aizu, Graduation Thesis. March, 2012 s1170033Further, data shows that all the highest frequenciesare recorded for 1/3rdside, back, 1/3rd back positions.The lowest mean accuracy scores were recorded forhitting chest 1/3rd back positions at .66, hitting waist1/3rdside positions at .68 and other hitting positionsalso recording lower mean accuracy scores. With over80% accuracy scores, frequency data shows over 30individuals performing the matching task correctly.I then performed a non-parametric Cochran’s Q testfor binary data (0 = inaccurate; 1 = accurate) for the 5angular rotations at “holding bat at chest height”.Results show that with Cochran’s Q value at 4.182 andp = .382 > .05, there is no significant differencebetween the different matching tasks at holding chestheight for 5 angular rotations.An overall Cochran’s Q test for all the 20combinations of data (5 angular rotations, height andbat action) shows a value of - 17.968, with Asymp. Sig= .525.For hitting at chest position for 5 angular rotations,data shows a value of 6.552 with Asymp. Sig = .162.Although data shows statistically insignificantdifference between the 5 matching tasks in the group,it certainly shows more diverse data when compared tothe “holding chest” group.Data show that for “holding bat at the waist height”combinations for the 5 angular rotations there isinsignificant difference between the mean accuracyscores. A Cochran’s value of 2.615 and p = .624 goeson to show the insignificance. However, data doesindicate that the accuracy performance is less variedfor “holding-waist” group than it is for “hitting-chest”group.Data further shows that there are statisticallysignificant difference accuracy scores between the 5angular body positions for the 5 “hitting-waist”combinations. With a Cochran’s test value of 14.122and a p value = .007 < .05, we see that angularrotations for hitting waist positions did not call for thesame type of accuracy scores. This evidence showsthat when compared to all other groups, the data ismore varied between these 5 matching tasks.Comparative accuracy scores between four frontpositions between the chest and waist heights and foractions (holding or hitting) show a difference in meanaccuracy scores between 78 ~ 90%. The comparativeaccuracy scores between the 1/3rdside positionsbetween the chest and waist heights and for actions(holding or hitting) show a difference in meanaccuracy scores between 68 ~ 93%. Results suggestthat hitting waist 1/3rdside with 68% accuracy wasway lower than any other position combinationdiscussed so far. The other hitting position at chestheight had much more accuracy at 83%. But overall, itlooks like the holding positions were relatively easierto complete. Results suggest that hitting positions onside angles has relatively lower levels of accuracyaround 76 ~ 78%, but the holding positions (chest andwaist) have higher accuracy scores at 85%.For the confidence self-reports on the 5 angularrotations for the holding chest positions, we see avariation in self-confidence levels in a 1 ~ 5 scalebetween 3.50 ~ 3.98. Interestingly, front and 1/3rd sidepositions clearly show higher levels of comfort andconfidence.Interestingly, for hitting chest positions we clearly seea lowered confidence level around the 3.5 levels for allthe given angular rotations. Even when the confidencelevels are lower when compared to the holding chestpositions, even within this hitting-chest group we seequite a difference in confidence levels between frontposition at 3.43 and 1/3rd back position at 3.63.Surprisingly, we see higher confidence levels for 1/3rdback positions, whereas for back position, theconfidence is quite lower.This data is not conclusive and indicative of anypattern, but there exists some indications thatcanonical viewpoints show a strong correlationbetween actual accuracy scores and confidence.4 DiscussionsIn the review of the literature, we had a section onhow motor skills and related performance happensfor physical tasks. We wanted readers to be consciousof the fact that types of actions shown (discrete, serialor continuous), cognitive information processing bythe actor, linking motor skills and cognitive elements,and environmental factors for e.g., consideration ofwind factors (while bowling in a game of cricket),ground slope (when playing golf) etc., technicallyand practically have a bearing on how the physicaltask is completed. However, in this study we couldnot consider it to be a factor that influencesunderstanding of illustrations. Rather, we wantedreaders to know that it becomes a factor when readersprobably try to emulate the action based on theircomprehension of the illustration. Comprehension ofhow the task is to be completed and actualimplementation of the task are different factors andreaders should be aware of the fact that actualimplementation needs more calculation and judgmentbased on specific context of action which probablycan’t always be designed as part of technicalillustrations. Motor learning is based on motor
  6. 6. 6University of Aizu, Graduation Thesis. March, 2012 s1170033performance and is different from learning about anaction from a technical illustration with visibleviewpoints. Technical illustrations will work forinitial comprehension of action patterns, but beyondthat, motor learning and performance shouldcomplement each other.5 ConclusionsThis study is aimed at carrying forward the studiesperformed by Krull et al (2004) [10]. As compared toprevious studies by Krull et al., this study aimed atincluding more variations in actions and body heightsand making those positional features more explicitand detailed. Further, with this study the aim was toinclude a serious group of participants who actuallyparticipated in this exercise for a grade. Futurestudies should continue to include more variations inbody height and action types, with more details andobjects in and across the line of sight. This study doesallow us to see the importance of different variablesand how it influences performance. More testing isneeded before we could definitely reach a conclusionabout the preferences that readers might have forvisualization purposes. Finally, besides testing withdifferent variations on body height – actioncombinations, future testing should also makealterations to the way the current experiment has beendesigned to more systematically include more optionsfor test sheets.Reference[1] Michel-Ange Amorim et al., “Embodied SpatialTransformations: Body Analogy for the MentalRotation of Objects” American PsychologicalAssociation, Vol. 135, no. 3, pp. 327-347, 2006.[2] Johnson A.M., “The speed of mental rotation as afunction of problem-solving strategies.” Perceptionand Motor Skills, Vol. 71, no. 3, pp.803-806,Dec.1990.[3] Jones B et al., “Effects of sex, handedness,stimulus and visual field on “mental rotation”.”Cortex, Vol. 18, no. 4, pp. 501-514, Dec. 1982.[4] Hertzog C., “Age differences in components ofmental-rotation task performance.” Bulletin of thePsychonomic Society, Vol. 29, no. 3, pp. 209-212,May. 1991[5] Viola I., Kanitsar A., Groller M.E., “Importance-driven feature enhancement in volume visualization”IEEE, Vol.11, No.4, pp.408-418, July-Aug, 2005.[6] H. Gardner, Frames of Mind: The Theory ofMultiple Intelligence New York: Basic Books, 1983[7] Krull R., “Writing for Bodies in Space”Proceedings of the IEEE ProfessionalCommunication Society, September, 2001.[8] Robert Krull, Debopriyo Roy, Shreyas D’Souza,Marilyn Morgan, “User Perceptions and Point ofView in Technical Illustration s”, STC Proceedings,2003.[9] Robert Krull, Shereyas J. Dsouza, Debopriyo Roy,AND D. Michael Sharp, “Designing ProceduralIllustrations” IEEE TRANSACTIONS ONPROFESSIONAL COMMUNICATION, VOL. 47,NO. 1, MARCH 2004[10] Szlichcinski, “The syntax of pictorialinstructions” In P.A. Lolers, M.E Wrolstad, and H.Bouma(Eds.) Processing of Visible Language, Vol. 2,pp. 113-124. 1980[11] Heiser J. and B. Tversky, “Diagrams andDescriptions in Acquiring Complex Systems.”Proceedings of the 24thAnnual Meeting of theCognitive Science Society, Fairfax, VA, August, 2002.[12] C.J. Erkelens “Interaction of monocular andbinocular vision” Perception 39 ECVP AbstractSupplement. 2010.[13] Kenneth J., Hochberg, ”A SIGNED MEASUREON PATH SPACE RELATED TO WIENERMEASURE” The Annals of Probability, Vol.6, No.3,Jun 1978.[14] H. Goldstein, “Communication Intervention forChildren” Journal of Autism DevelopmentalDisorders, Vol. 32, No. 5, October, 2002.[15] A. David Milner and Melvyn A. Goodale, “Thevisual Brain in Action” Great Clarendon Street,Oxford OX2 6DP, 1995.[16] Zacks et al., “Mental Spatial Transformations ofObjects and Perspective.” Spatial Cognition &Computation, pp. 315-322, 2002.[17] Schmidt Richard, & Wrisberg Craig, “MotorLearning and Performance” Human KineticsPublishers, United States, 2008.