“…Forthesmartphone,thelimiteddisplaysizecouldincreaseusers'memoryload (Chae&Kim, 2004).Therearetwowaystodealwithlimiteddisplay.Thefirstwayistostaywiththetreestructure andimproveitsdesign.Previousstudieshaveeitherprovidednavigationtoolsorbalancedmenu depthandbreadth (Zhou,Rau&Salvendy,2012;Ziefle,2008Ziefle, ,2009.Menubreadthmightconflict withfontsize.Displayingfivemenuitemsperpageonfeaturephoneswasbetterthandisplaying onemenuitemperpage,and12pt.fontsizewasbetterthan8pt. (Ziefle,2010).Anavigationtool, whichaddedsurveyknowledgetothetreestructureoffeaturephones,helpedusersachievebetter interactionperformance (Ziefle&Bay,2006).Thesecondwayistoabandonthetreestructure.A piemenuwithroundpatternwasdesignedandcomparedtothelinearmenu.Resultsshowedthatthe piemenureducedtargetsearchingtimeanderrorrates (Callahan,Hopkins,Weiser&Shneiderman, 1988).Also,theroundrotatingmenuwasimplementedonapersonaldigitalassistant(PDA)prototype andgainedpositivefeedbackfromolderadults (Zao,2008).…”