In navigation from one place to another, spatial knowledge helps us establish a destination and route while travelling. Therefore, sufficient spatial knowledge is a vital element in successful navigation. To build adequate spatial knowledge, various forms of spatial tools have been introduced to deliver spatial information without direct experience (maps, descriptions, pictures, etc.). An innovation developed in the 1970s and available on many handheld platforms from the early 2000s is the Global Position System (GPS) and related map and text-based navigation support systems. Contemporary technical achievements, such as GPS, have made navigation more effective, efficient, and comfortable in most outdoor environments. Because GPS delivers such accurate information, human navigation can be supported without specific spatial knowledge. Unfortunately, there is no universal and accurate navigation system for indoor environments. Since smartphones have become increasingly popular, we can more frequently and easily access various positioning services that appear to work both indoors and outdoors. The expansion of positioning services and related navigation technology have changed the nature of navigation. For example, routes to destination are progressively determined by a “system,” not the individual. Unfortunately we only have a partial and nascent notion of how such an intervention affects spatial behaviour. The practical purpose of this research is to develop a trustworthy positioning system that functions in indoor environments and identify those aspects those should be considered before deploying Indoor Positioning System (IPS), all towards the goal of maintaining affordable positioning accuracy, quality, and consistency. In the same way that GPS provides worry free directions and navigation support, an IPS would extend such opportunities to many of our built environments. Unfortunately, just as we know little about how GPS, or any real time navigation system, affects human navigation, there is little evidence suggesting how such a system (indoors or outdoors) changes how we find our way. For this reason, in addition to specifying an indoor position system, this research examines the difference in human’s spatial behaviour based on the availability of a navigation system and evaluates the impact of varying the levels of availability of such tools (not available, partially available, or full availability). This research relies on outdoor GPS, but when such systems are available indoors and meet the accuracy and reliability or GPS, the results will be generalizable to such situations.

Study of complex networks by researchers from many disciplines has provided penetrating insights on various complex systems. A study of the world wide web from a network theoretic perspective has led to the design of new search engines [65]. The spread of diseases is now better understood by analyzing the underlying social network [26]. The study of metabolic networks, protein-protein interaction networks and the transcriptional regulatory networks with graph theoretic rigor, has led to the growing importance of an interdisciplinary approach [71]. Network centrality measures, which has been of interest to the social scientists, from as long as 1950 [13], is today studied extensively in the framework of complex networks. The thesis is an investigation on understanding human navigation with a network analytic approach using the well established and widely used centrality measures. Experiments were conducted on human participants to observe how people navigate in a complex environment. We made human participants way-find a destination from a source on a complex network and analyzed the paths that were taken. Our analysis established a fact that the learning process involved in navigating better in an unknown network boils down to learning certain strategic locations on the network. The vertices in the paths taken by the participants, when analyzed using the available centrality measures, enabled us to conclude experimentally that humans are naturally inclined to learn superior ranked vertices to navigate better and reach their intended destination. Our experiments were based on a word game called the word-morph. A generalized version of the experiment was conducted on a 6x6 photo collage with an underlying network hidden from the participant. A detailed analysis of the above experiment established a fact that, when humans are asked to take a goal-directed path, they were prone to take a path that passed through landmark nodes in the network. We call such paths center-strategic. We then present an algorithm that simulates the navigational strategy adopted by humans. We show empirically that the algorithm performs better than naive random walk based navigational techniques. We observe that the algorithm produces rich center-strategic paths on scale-free networks. We note that the effectiveness of the algorithm is highly dependent on the topology of the network by comparing its functionality on Erdos-Renyi networks and Barabasi-Albert networks. Then we discuss a lookahead algorithm to compute betweenness centrality in networks under vertex deletion operations. We show that the widely used Brandes algorithm can be modified to a lookahead version. We show that our proposed algorithm performs better than recomputing the betweenness centrality values in the vertex deleted graph. We show that our method works 20% faster than the Brandes algorithm.

abstract: When a rolling ball exits a spiral tube, it typically maintains its final inertial state and travels along straight line in concordance with Newton's first law of motion. Yet, most people predict that the ball will curve, a "naive physics" misconception called the curvilinear impetus (CI) bias. In the current paper, we explore the ecological hypothesis that the CI bias arises from overgeneralization of correct motion of biological agents. Previous research has established that humans curve when exiting a spiral maze, and college students believe this motion is the same for balls and humans. The current paper consists of two follow up experiments. The first experiment tested the exiting behavior of rodents from a spiral rat maze. Though there were weaknesses in design and procedures of the maze, the findings support that rats do not behave like humans who exhibit the CI bias when exiting a spiral maze. These results are consistent with the CI bias being an overgeneralization of human motion, rather than generic biological motion. The second experiment tested physics teachers on their conception of how a humans and balls behave when exiting a spiral tube. Teachers demonstrated correct knowledge of the straight trajectory of a ball, but generalized the ball's behavior to human motion. Thus physics teachers exhibit the opposite bias from college students and presume that all motion is like inanimate motion. This evidence supports that this type of naive physics inertial bias is at least partly due to participants overgeneralizing both inanimate and animate motion to be the same, perhaps in an effort to minimize cognitive reference memory load. In short, physics training appears not to eliminate the bias, but rather to simply shift it from the presumption of stereotypical animate to stereotypical inanimate behavior. / Dissertation/Thesis / M.A. Psychology 2013

Finding the right path is a key aspect for successful navigation through the environment, with technologies such as the Global Positioning System (GPS) having improved this. However, human navigators can still be met with incorrect information either from devices or peers. The literature on how individuals then successfully navigate is limited. The current study attempts to fill in some of the gaps, assessing both individual and group differences. The navigation performance of twenty-five young adults was tested using a Virtual Environment (VE) built with Unreal Engine 4. Participants’ self-assessment of spatial ability, trait anxiety, and wayfinding preferences was further assessed through a series of pre- and post-test measures. Using quantitative data analysis, no significant differences in wayfinding strategies when given incorrect information were found and furthermore there was no interaction between trait anxiety and navigational performance. However, participants in general experienced increased difficulty when the incorrect information given was with regards to landmarks. Furthermore, males had decreased accuracy compared to females but only when given incorrect turn information. Even with this lower performance in terms of accuracy, males still rated themselves higher with regards to spatial ability. These results are particularly interesting for human navigation research and might be used to improve GPS-devices or other technology used for navigation (e.g. taking into account gender differences). Further research is needed due to some limitations present in the current study including a limited sample size. / Att hitta rätt väg är grunden för att lyckas hitta rätt väg genom sin omgivning och modern teknologi som GPSen (Global positioning system) har förbättrat detta. Dock så kan en mänsklig navigatör fortfarande presenteras med felaktig information, vare sig det är från teknologiska enheter eller andra individer. Den litteratur som är tillgänglig angående hur folk anpassar sig till detta och ändå försöker finna rätt väg är  begränsad. Denna studie är till för att fylla denna kunskapslucka, både på individuell och på gruppnivå. 25 unga vuxnas navigationsförmågor undersöktes med hjälp av en virtuell miljö skapad i Unreal Engine 4. Deltagarna självutvärderade också sina spatiala förmågor, ångestbenägenhet samt preferenser när det kommer till att utforska och hitta rätt väg. Något som i sin tur komplementerades både före och efter själva experimentet. Kvantitativ dataanalys uppvisade inga märkbara skillnader i navigeringsstrategier när felaktig information hade getts och ingen koppling kunde etableras mellan ångestbenägenhet och prestation. Det fanns dock en trend i upplevda svårigheter när felaktig information angående milstolpar angavs. Män presterade sämre med lägre precision än kvinnor vid missvisande information om svängtillfälle. Men trots detta hade männen en tendens att betygsätta sin spatiala förmåga högre än kvinnor. Dessa resultat är av specifikt intresse för forskning inom navigation och kan användas till att förbättra GPS-enheter samt annan teknologi som utnyttjas för liknande syften (t.ex. för att ta hänsyn till könsskillnaderna). Men mer forskning krävs på grund av vissa begränsningar i undersökningen, inklusive en begränsad provstorlek.

This master thesis presents an overview of psychological and neurological the- ories and research of human navigation, how it works, what systems it con- sists of and what external information it requires to operate. I present several experiments administered in virtual environment which tested the process of accessing two discrete spatial reference frames: allocentric landmark-centred and object-centred. The research tries to answer whether these reference frames interface during the learning phase and whether their access is sim- ultaneous or sequential. Data from my experiment are partially concordant with previous research and imply that the two representations exist inde- pendent of each other. Subjects tend to manifest longer reaction times during the spatial task when they need to change the reference frames in order to provide a correct answer. But the data also suggest that the switch from the object-centred reference frame does not occur prior to the task itself, which is conflicting with previous studies. Possible explanations are discussed. keywords: human navigation, switching, environmental representations, object- centred reference frame, virtual reality 1

A desktop virtual reality environment of a campus area (called Silcton) was used to examine how instructing participants on performing exploration in an unfamiliar environment impacts the acquired spatial knowledge. Participants explored the Silcton virtual environment, after having received differing instructions on what to do. Two instruction conditions were tested: (i) the participant was provided with instructions to freely explore the Silcton virtual environment for at least 10 minutes (ii) the individual explored the environment while being instructed to pay specific attention to the environment’s layout. By providing different types of instructions before exploring an unfamiliar environment, we can learn more about how the instructions' wording impacts the acquired spatial knowledge, especially when aiming for a particular behavior or memory effects. We also tested for participants’ spatial abilities and observed differences between genders and based on individual differences. The present study shows no statistically significant differences in pointing and model-building scores between any of the tested groups, namely, the different instruction groups, gender, and groups with 'low' and 'high' spatial abilities. Time spent in the environment and pointing error showed a significant negative correlation, which indicates that as experience with the environment increases, participants become better at pointing to targets in the environment. The lack of significant results might be attributed to the overall small sample sizes and/or the distribution of men and women in the two instruction groups. Therefore, for future research a close monitoring of the experimental process and a larger retainment of participants are required to provide solid evidence and draw any general conclusion. / En stationär virtuell verklighetsmiljö på ett campusområde, kallad Silcton, användes för att undersöka hur instruktioner för deltagare relaterat till att utforska okänd miljö påverkar den förvärvade rumsliga kunskapen. Deltagarna utforskade Silctons virtuella miljö, efter att ha fått olika instruktioner om vad de ska göra. Två instruktionsförhållanden testades: (i) deltagaren fick instruktionen att fritt utforska Silctons virtuella miljö i minst 10 minuter (ii) deltagaren fick instruktionen att utforska miljön samtidigt som han skulle ägna särskild uppmärksamhet åt miljöns design. Genom att tillhandahålla olika typer av instruktioner innan vi utforskar en okänd miljö kan vi lära oss mer om hur instruktionernas formulering påverkar den förvärvade rumsliga kunskapen, särskilt när man siktar på ett visst beteende eller visa minneseffekter. Vi testade också för deltagarnas rumsliga förmågor och observerade skillnader mellan könen och individuella skillnader. Resultatet för studien visar inga statistiskt signifikanta skillnader i pek- och modellbyggande poäng mellan någon av de testade grupperna, nämligen de olika instruktionsgrupperna, kön och grupper med "låga" och "höga" rumsliga förmågor. Tid i miljön och pekfel visade en signifikant negativ korrelation, vilket indikerar att när erfarenheten med miljön ökar blir deltagarna bättre på att peka på mål i miljön. Bristen på signifikanta resultat kan hänföras till de övergripande små urvalsstorlekarna och/eller fördelningen av män och kvinnor i de två instruktionsgrupperna. Därför krävs för framtida forskning en noggrann övervakning av den experimentella processen och ett större antal deltagare för att tillhandahålla solida bevis och dra några allmänna slutsatser.