Review of Sinha et al. – “An Ontology Design Pattern for Surface Water Features”

September 23rd, 2019

In “An Ontology Design Pattern for Surface Water Features” (2014), Sinha et al. proposed an ontology of Surface Water to generalize distinguishable characteristics with an aim to make it interoperable between different cultures and languages, as well as to help build the Semantic Web. To achieve this, the authors distinguished the container from the water body, separating them in two distinct parts; the Dry module referencing to the terrain and the Wet module referencing to the water body. They also emphasize that the Wet module is dependent on the Dry module to exist, meaning they are superposed when the former is present.

The article provides a great approach to analyze the ontology of surface water features by generalizing both the Dry and Wet module in a limited number of classes while also preserving a sufficient number of defining features. An interesting example would be in their characterization of a water body, which even encompasses endorheic basins, in other words a drainage basin that has no outflow to another water body, as they didn’t specify the need for it to have an outlet point. With that said, while this ontology mentions that water movement is dictated by gravity, there are some instances of water bodies flowing uphill, such as a river under the ice sheet of Antarctica or the flow reversal in a water body following an cataclysm. In that case, this would challenge the assumption that water always flows from a high point to a low point. 

Thoughts on “An Ontology Design Pattern for Surface Water Features”

September 23rd, 2019

This paper takes on a huge challenge in trying to formalize GIS hydrographic data for semantic technology by developing an ontology for surface water. One issue it covers is how “surface water features have physical qualities that can lead to socially defined functions and roles” (Sinha et al 2014). The authors address this in part by creating the :Function class, “with criteria that if a particular feature bearing a quality, role, disposition, or function is removed, the feature may be changed, but continues to exist” (Sinha et al 2014). This seems to be a reasonable way to address what should happen to a feature whose use is discontinued; however, the paper does not mention a class that addresses what happens when a feature’s function is changed but not removed. For example, how would this ontology account for a former hydro dam that’s now used as a bridge? There are many important questions that the paper fails to address with respect to a feature’s “socially defined functions and roles.” How can less obvious instances of such functions and their impacts be determined? For example, how many people fishing in certain areas of a river would it take to affect its flow rate? What are the impact of non-human uses of water bodies, like a beaver building a dam? What features of the river, classified in this extensive ontology, are associated with certain usages (for example, a slow flow rate or a wide river bed)? The authors have created quite a thorough ontology with respect to certain human uses, such as bridges, canals, gates, and levees; however, the more nuanced considerations outlined above appear to be underdeveloped and could be built upon in future work.

Thoughts on “Do Mountains Exist? Towards an Ontology of Landforms”

September 23rd, 2019

While this piece is quite abstract, I glommed on to one particular contention that applies beyond mountains to other areas of science. On page 4, the authors state that they can rephrase the question “do mountains exist?” as “do we need to accept… mountains in order to attain good explanations or… good… theories?” (Smith and Mark 2003). They then go on to describe theories about human and animal behavior that may utilize mountains to make sense and be accurate. This line of thinking reminded me of the famous experiment carried out by Ernest Rutherford (at McGill) that confirmed the existence of an atom’s nucleus in the 1800s. Although Rutherford could not observe a nucleus himself, the presence of a nucleus was the only feasible explanation for why he repeatedly obtained a specific set of results in his experiments. In this way, one could say the question “does a nucleus exist?” was answered by asking “do we need to accept nuclei to attain good explanations for Rutherford’s experiments?” The same may be said of the beetle experiment mentioned in this paper. Even setting aside the assumption that mountains exist, the entomologist’s results point to mountains existing; they must exist for the beetles to concentrate at their peaks. Therefore, this rule of thumb resonates with me as I can see it being applied not only in geography but other scientific fields as well. An important question that stems from using this line of reasoning is how to prove that something exists if it does not need to be accepted to attain good explanations or good theories, or whether determining if such a thing exists is even worthwhile. Unfortunately, answering such questions is beyond the scope of this blog post… but it has got me thinking.

Thoughts on “Do geospatial ontologies perpetuate Indigenous assimilation? (Reid & Sieber, 2019) “

September 23rd, 2019

This article uncovers the fact that there is no universality in the field of ontology. This means there is no one formalized rule towards geospatial topology. The emergence of indigenous ontology means that people started to realize that people with different cultural background can percept the land and environment differently. This realization is important because new technologies which involves citizen science and crowdsourcing have emerged greatly, and those technologies might want to figure out a way to formalize people’s perception towards the land and its surrounding environment. Take OpenStreetMap as an example, they want every contributor to have a consensus about what is the boundary of a river or what can be labeled as residential area. However, indigenous communities do not categorize geographic entities in distinct categories, which means their understanding of a river can be different and both physically and spiritually. So they might find it hard to contribute to OpenStreetMap since they might perceive river different than western communities.

I think this realization of no universality in geospatial ontology is important worldwide. Although I do not have previous research about indigenous groups, I can very much relate it to China’s diverse ethnic background. China has 55 minority ethnic groups and one majority group. The majority groups covers 91% of the nation’s population, and the rest 9% was divided into 55 distinct ethnic groups. The minority groups each have their different understandings towards entities and some of them have completely different language systems. This difference would made even one nation hard to address universality in ontologies. Other than China, some of the other Eastern countries and territories also have a considerable amount of ethnic groups.

So how do we address each different culture and context worldwide when there is not only indigenous communities but also great number of ethnic groups? If there is some overlap of ontologies between different groups, how can we make use of it? As it is mentioned in the article: “Indigenous people can be directly involved in the shaping and crafting of ontologies.”, can ontologies be quantifiable or in other words be “crafted” if it involve spiritual or philosophical meanings? What might happens if indigenous ontologies are contradict with conventional ontologies?

Review about reading Sinha and Mark et al’s An Ontology Design Pattern for Surface Water Features.

September 23rd, 2019

In Sinha and Mark et al’s paper, “An Ontology Design Pattern for Surface Water Features”, the authors works together to introduce Surface Water pattern, in order to generalize and standardize the semantics of basic surface water related features on earth’s surface. Their incentive to create this model is to resolve the differences of semantics description around the world, on describing surface water related feature and terrain. To bring convenience and precise description on surface water features are the essence of their work.

In the Surface Water pattern, they divided Earth’s surface water system into two parts: Dry module and Wet module. The Dry module, which they used to describe the landscape that is able to contain water body/flow, contains: Channel, Interface, Depression. Channel describes the landscape that allow water to flow, tend to have two ends (start/end point), which they latter describe as Interface. Interface is where channel start and end, and if the Interface include interaction with other surface water related landscape (e.g. another Channel or Depression), it is a Junction (subclass). And depression, they describe as a landscape that can contain water body, so it does not over flow. It is usually surround and enclosed by a rim (which is usually a contour line represents the highest elevation of the depression).

The Wet module is about actual water (or in their further discussion, to be any liquid has the capability to flow) body/flow. It includes Stream Segment, Water Body, and Fluence.  Stream Segments represents water flow in Channel (from the Dry module), which has only one start and end point (later explained as Influence and Exfluence), which is not necessary the Interface for the Channel it flows within. Water Body is the water that sit relatively still inside Depression (from the Dry module). It is also included by the rim of Depression. Fluence describes the start and end point of Stream Segments. If it is the start point of Stream Segments, it is called an Influence. Otherwise, it is called an Exfluence. If it is where one Stream Segment interact with another Stream Segments or Water Body, it is a Confluence.

And the end. Sinha and Mark et al explained that the Surface Water pattern did not cover every features that needs to be describe as part of Earth’s surface water system, such as features related to glaciers and ice flows. It rather serves as a frame work that can be extended, and further developed to more specific Ontology. And the Surface Water pattern should be describing basic features for all flowing liquid including water, and on all planet with gravity.

My major critics on their Surface Water pattern is: although they said Wetland (as an important feature in surface water system) may not be described using their pattern in the discussion part, it is not proper to call their Onotology design as “Surface Water” when they clearly excluded wetland as a necessary part of Earth’s surface water system. The reason I claim that it is a major flaw for excluding wetland in their Surface Water pattern is: wetland in Dry module, neither fits their definition for Depression (since wetland not necessarily have a rim), nor can be described as a series of Channel (it does not have to contain flowing water). Even though in their discussion of their Onotology pattern, they stated that wetland can be developed in a different Ontologiy pattern or future extension of this pattern, it still creates confusion when they name their pattern as Surface Water but not including all parts of surface water.

An Ontology Design Pattern for Surface Water Features (Sinha et al., 2014)

September 22nd, 2019

Sinha et al. (2014) aimed to create a widely-applicable, foundational ontology for the classification of surface water features to aid in database interoperability. The authors do this by distilling surface water features into (near-)universally recognizable elements in two distinct and separate classes: Dry and Wet. Wet classes are contained within the physical bounds of the Dry features. By doing this, they base the pattern on physical properties of the landscape rather than properties of the surface water features themselves which can be variably interpreted between culture, region, or occupation.

Developing this sort of foundational standardization is important for database interoperability, user-friendliness, and intercultural ontological adaptability. The authors have done well in explaining both the limitations and the abilities of this pattern and where the pattern may be expanded to accommodate ontological differences or situational needs.

I think that the extent to which the authors were able to abstract these concepts is very impressive, as well as how expandable they have been able to make this system of organization. It is good that they have emphasized the expandability aspect of the pattern rather than trying to create a new standard for hydrological databases. A criticism that I have is only where the pattern cannot be applied, at least not as effectively; both areas were touched on in the article, but it cannot be applied to snow- or ice-cover, and it is much more complicated in wetlands where boundaries are blurry and permeable. This makes it much less useful in areas where water is the dominant landscape feature and it could be most useful.

Thoughts on “Do geospatial ontologies perpetuate – Indigenous assimilation?”

September 22nd, 2019

The article written by Reid and Sieber discusses the underlying ontology development which reveals the central motivation in the academic fields of GIScience and computer science — making data interoperable across different sources of information. Moreover, the authors explore how the ontology theories should be better developed considering indigenous knowledge inclusive. The title raises up a question while at the end of the paper they answer that: With approaches suggested — indigenous place-based approach and deep engagement with indigenous methodologies for ontology co-creation (participatory approach), Indigenous conceptualizations would be taken seriously and never assimilated by western concepts in ontology development.

I find this paper really interesting for that it brings about the doubts for the conventional geospatial ontology development and asserts the importance of indigenous knowledge. I think not only indigenous knowledge should be emphasized but also many other unique cultures which are not consistent with the advanced western regime. However, constructing a universal ontology is fundamental and a main focus in GIS and CS for data collection, management, control, sharing and etc, and different cultures involved in ontology creation may make the universality much more complicated to understand or communicate. I think maybe sometimes we can create specific ontologies for special case with localized problems.

Introduction – Elizabeth

September 22nd, 2019

Hello everyone! My name’s Elizabeth Stone and I am a 4th year undergrad majoring in Geography, with minors in GIS and Economics. I am from Newtown Square, Pennsylvania, which is just outside of Philadelphia.

I do not have any specific research projects that I am currently working on, but I am very interested in a range of topics. I am a very active, outdoorsy person, and so I am very interested in how geography interacts with my love for wild places. More specifically, I am interested in how GIS intertwines with such topics as conservation, environmental management, ecology, sustainability, and ecological economics.

I spent this past summer in Olkiramatian, Kenya as an intern for a conservation NGO, and so I am currently very interested in environmental topics which deal with this region, whether that be looking at  methods to mitigate human-wildlife conflict, or how increasing development is impacting wildlife migration corridors, to name a few examples.

Do geospatial ontologies perpetuate Indigenous assimilation? (Reid & Sieber, 2019)

September 22nd, 2019

To answer the title of the paper succinctly: yes, geospatial ontologies do perpetuate Indigenous assimilation when no Indigenous perspectives are considered; however, if researchers do consider Indigenous perspectives, decolonization of geospatial research is possible. Indigenous people across the globe view their landscape much differently than western geographers do; for example, physical entities can have their own agency, there are less abrupt changes between different aspects of the landscape, and often there is no separation between cultural beliefs and the entity itself.  With more Indigenous experts participating in discussions of ethnophysiography and geospatial ontologies, it appears that there can be no universality of geospatial ontologies and that multiple worlds must exist.

Concerning GIScience, ontologies have an important place in discussing landscape perspectives, especially in an ever-connected and technologically-driven world where standardization and simplicity reign. With the rise of the neogeography and VGI, geospatial ontologies are more important than ever, as everyone who is contributing geographic data should view physical entities of their landscape in a similar manner in order for the data to be viewed as accurate and useful.

After reading this paper, I have some questions regarding Indigenous ontologies and geospatial ontologies generally: how much differentiation is there between different Indigenous groups’ perspectives of their landscape? How often was universality discussed before the creation of the internet? What is the research on ontology universality like today – is it still a popular field of research like it was in the 2000s?  How do Indigenous perspectives translate to modern technology – do computers have trouble understanding their view of the landscape? What else is being done to decolonize geographic research?

I realize some of these questions might have answers in other literature, especially since I do not have a lot of prior research in Indigenous studies nor ontologies, and I welcome any response educating me or pointing me in the direction of other papers that may answer my questions.

-Elizabeth

 

 

Introducing Myself _ Qiao

September 22nd, 2019

Hi everyone. My name is Qiao Zhao. I am from China. I am a PhD student in the Department of Geography. My supervisor is Prof. Kevin Manaugh.

Cycling is prevalent among low-come and minority communities, but it is sometimes described as a white thing. Equity has emerged as an important consideration for transportation officials working on developing connected multimodal systems that provide meaningful choices in transportation. However, bicycle equity makes up a relatively small segment of the transportation equity literature. My research explores questions related to transportation equity. I focus particularly on issues related to cycling and on the experiences of disadvantaged populations.

My research aims to provide a comprehensive methodology for bicycle network planning in order to assistant governments in providing cycling infrastructure in an equitable manner. I integrate multiple methodologies into my research including statistical analysis and geographic information systems to try to understand how to improve the ability of disadvantaged populations to travel safely and conveniently via cycling and achieve an equitable transportation system that can provide options in how people access various destination.

My supervisor and I are working on assessing the impact of elevation on commuter mode choice at the census tract level.

Indigenous Geospatial Ontologies (Reid & Sieber, 2019)

September 22nd, 2019

In this paper, Reid and Sieber (2019) argued that universality in geospatial ontologies may disempower Indigenous knowledge holders and assimilate Indigenous people. They compared Indigenous ontologies with geospatial ontologies and argued that conventional ontologies fail to take into consideration Indigenous conceptualizations including: 1. Continuum between mental processes and the physical; 2. Inclusivity of all entities; 3. Agency in geographic entities and natural phenomena; and 4. Predominance of relationships. While I haven’t read much of the literature on geospatial and Indigenous ontologies, the paper is easy to follow and makes the complex topic easily understood and digestible. Even so, it does seem a bit thin on solutions for overcoming the issues it well described.

The authors introduced some methods used to address universality in conventional ontologies. They stated that the integration of participatory approaches and geospatial ontologies provides ample opportunities to capture and represent Indigenous conceptualizations of spatial phenomenon, which reminds me of the issues of researcher’s positioning in participatory research. The researchers who have been perceived by Indigenous people as outsiders may have to spend a long period to build trust and rapport with the participants. Also, power relationships are highlighted while a range of Indigenous experts is involved in the development of ontologies. Would high-power people play larger roles in the process? Further, I am left wondering how to incorporate qualitative data into geospatial ontologies and GIS.

Sakar and al. Animal Movement.

December 4th, 2017

This paper focuses on movement data from barnacle goose migration patterns. By using migration hotspots with periodicity and directionality from these hotspots they are able to establish the movement patterns of these geese. I’m not sure if geese have a need for privacy but if they do, attaching GPS trackers to them would definitely be an invasion of privacy. This study also highlights the relationship between location information and information about an individual/animal quite well. Location information is a critical piece of information about the identity of what’s moving.

I thought this paper was very well written; I am left with very few questions bout the effectiveness of the methods. Notably, the paper accounts for the effect of weather and ecological stresses from certain hotspots that affect the movement of the geese. Considering that these stresses have already affected movement, it would be interesting to see how the migration patterns will be affected on a longer timeframe. Will urbanization, climate change, atmospheric conditions continue to alter these patterns over time?

Written in 2015, this paper is well up to date in terms of the algorithms, clustering methods and GPS devices used. It would be interesting to compare and contrast the migration of other geese (perhaps the Canada goose) using the same tracking methods. Perhaps there would be fundamental law’s of goose travel that would become more apparent.

Analyzing Animal Movement Characteristics From Location Data (Sarkar et al., 2016)

December 3rd, 2017

This paper adopts Periodica algorithm by enhancing the hotspot detection, which accomplished through substituting Kernel Density Estimate (KDE) with Getis-Ord Gi*. The new method is applied in periodical behavior discovery in animal movement. It is a very typical case in spatial data mining for integrating spatial autocorrelation with traditional statistical analysis. As the author mentioned, KDE is criticized because it assume data points are independent and sensitive to the shape of data points. Getis-Ord Gi* perfectly avoids these drawbacks; however, Getis-Ord Gi* is grid-based and still suffering from Modifiable Areal Unit Problem (MAUP). It means the model will have different results when applied in different spatial scales, which represents the granularity here. Considering the scale problems is a significant different between spatial data mining and traditional datamining. Therefore, it is important to explicitly discuss the size of grid in practices, and it is also to necessary to think about time scales. Periodical behaviors may simultaneously happen in many different-length and interlaced periods (e.g., seasonal behaviors and daily behaviors can happen together). Sometimes there is only one kinds of periods we need to consider (e.g., animal immigration), but sometimes we may need to have cross-scale analysis (e.g., human’s periodic behaviors), which will make the situation far more complicated.

Beyond the Periodica algorithm, I believe there could be a better way to discover the periodic behaviors. First, I think no matter what hotspot detection methods used, it never gets rid of arbitrarily determining the hotspots. More instinctively, it means how big a staying region is to represent a periodic behavior is happening. Second, since the points in trajectories are not independent, why we separate them from trajectories to conduct analysis? Can we directly analyze the trajectories even the basis are still points? Do we only care about the periodical behaviors within certain locations and how the directions they traveled? Is there any interesting periodic behaviors during the travelling (e.g., certain routes they always travel)? Simplifying information to binary data also means losing information for further discovering. I’m not arguing we always have to know all the answers of those questions, but when it is necessary, we should have better methods or tools to do the job. Third, in my perspectives, periodical behaviors mean always having some event in a certain time. There is nothing about space. I think most of literature have their clear definitions about periodical behaviors but seem not natural. Mathematically, it is good to make “hard” definitions for analysis, but we still need more discussion about this assumption (e.g., using locations to situate periodical behaviors). Therefore, I argue we should have better solution to substitute the Periodica algorithms if necessary, and I suggest it can start from the concept of clearly separating space from other information in spatial data mining.

Thoughts on Toch et al

December 3rd, 2017

This article gave me a much-needed injection of nuance into my views on privacy data. I found the concept of high and low entropy locations quite interesting, and how levels of comfort were correlated to these notions. By allowing the participants how to control their privacy settings based on time and location was quite very exciting. There is a narrative of location-tracking devices and apps imposing an authoritarian top-down imposition of privacy guidelines which is quite worrisome, so it comes at a pleasant surprise to see privacy guidelines being manipulated by the user rather than the creator. This potentially has a ‘win-win’ effect of reaping the benefits of location-tracking while phasing out moments in which one feels uncomfortable.
In a vacuum I like this quite a bit, but it sounds that this kind of narrative could potentially normalize the idea of location-based sharing. That is the direction in which we’re heading as each generation becomes more comfortable with this potential lack of anonymity. Additionally, by reaping in statistical data for different areas, we would be able to seemingly create models that determine which areas have high and low entropy. Wouldn’t we risk falling to certain biases based on the participants themselves? The positionality of those collecting the data must be considered, and even then, it would be impossible to account for everyone’s preference on a statistical basis. Statistical tools are generalizing by nature, so is it safe or ethical to infer too much data on what the data that it produces?
On a more positive note, I find the concept of low and high entropy in the context of location-sharing a potentially interesting tool of analyzing space. While in some space people would want to share their location publicly versus private spaces. What urban implications may this have? Could make for an interesting study.

Empirical Models of Privacy in Location Sharing (Toch et al, 2010)

December 3rd, 2017

In this paper, the authors propose a model for privacy location sharing, and investigate the relationships between the sharing behaviors and location characteristics and tracking methods. During the modeling process, it is meaningful to introduce entropy and apply it in later statistical analysis. However, I think that the other settings may lead to bias when conclude the results. The most influential factors may be the investigating system. How to communicate with participants and what they know about this project can lead to different location sharing behaviors. In my perspectives, the best datasets for analyzing privacy in location sharing are produced by users in daily life. The empirical environment is not natural for users and likely to change their behaviors. For example, we may doubt whether participants are more willing to share locations because they get pay from this project. We also don’t know whether they share locations on purpose in this project, which is not the natural states. Therefore, limitations can include that data come from particular applications and devices provided by researchers.

 

It is tricky to measure how comfortable people are willing to share their locations. Hence, it is necessary to ensure the natural inputs from participants (i.e., lessen the systematic errors). There are two possible ways we can improve privacy analysis in location sharing. In one hand, we should collect datasets from people’s daily life, which ensure the randomness of data. In the other hand, we can have more comprehensive data, participants, and context to simulate the natural environment rather than rely on a simple model.

On Sarkar et al. (2014) and movement data

December 3rd, 2017

I thought Sarkar et al.’s “Analyzing Animal Movement Characteristics From Location Data” (2014) was super interesting, as I don’t have a very strong background in environment and I didn’t know about all of the statistical methods involved in understanding migratory patterns via GPS tracking. The visualizations were super interesting, like the Rose diagram to show directionality and the Periodica method to then determine hotspots. I also appreciated the macroscopic viewpoint of this article; though the inclusion of equations is important for replication and critical understanding, it is also important to discuss the outputs and limitations of the equations at a larger level, in order to better understand results. It is especially useful for those without deep math backgrounds, like myself, to understand the intentions of using these certain equations without having the math background of being able to visualize output.

As interesting as it was to learn about the incredible utility of understanding migratory patterns of animals, I couldn’t help but think about applications to human geography. I wonder if these patterns are already being used to extrapolate information on someone based on their location, as the Toch et al. (2010) paper on privacy for this week hinted at. If they are different, it would be interesting to evaluate the utility of the methods to study human spatial data patterns as applied to animal migratory patterns. Since Sarkar et al. used unsupervised classification to learn new patterns, it seems like the combination of methods used could apply (and probably do apply) to human spatial data mining. As terrifying as that is.

On Toch et al. (2010) and location-sharing

December 3rd, 2017

This article was super interesting, as I didn’t know too much about the actual mechanics behind location sharing (ie. “Creating systems that enable users to control their privacy
in location sharing is challenging” (p. 129)). Their ideas of identifying privacy preferences based on the locations that people go to was confusing (and was not really ameliorated by the end). Perhaps it’s because I don’t understand Loccacino, particularly because of technology constraints from 7 years ago (did they or could they collect data then? All the time, or just when you wanted to share your location like “At the mall”?), underlined by the wonderful image of the “smartphone” (p. 131). Like some of my classmates noted, this seemed very similar to Find My Friends, and perhaps that’s why I didn’t understand how this worked, what the line was between actively volunteering and passively volunteering location.
Further, I had some issues with the participant pool that they used. The researchers relied on a set that was 22/28 male and 25/28 student and then were surprised that “the study revealed distinct differences between the participants, even though the population was homogenous”. As evident from spatiotemporal GIS & feminist GIS, women interact with spaces differently than men. Further, age of participants, as another classmate noted, is crucial: a 50-year-old staff member or student will go different places than a 22-year-old student. Not to mention, analysis of age could determine why there was a big difference in sharing (or if there was not a difference). Also, I was interested in seeing the differences between people between mediums, as some people used phones and some used laptops, and phones are way easier to pull out and share info on than laptops, especially in social gatherings or public spaces. They acknowledged this difference as being 9 mobile & 5 laptop users being “highly visible” (p. 135), but I would be more interested in seeing the differences between the two mediums first and seeing activity levels as a whole for the two mediums, rather than continuing to equate the two, especially since laptops and phones were not distributed equally among participants. I think this study would be interesting to redo today, but with more information about participants and more controls throughout the study (or at least, fixing for differences among participants and modes of participation).

Duckham and Kulik (2006) – Location privacy

December 2nd, 2017

In this chapter, Duckham and Kulik outline and compare four approaches to location privacy protection: regulation, privacy policies, anonymity, and obfuscation. The growing presence of locationally-aware devices (and applications) have increased both the richness of personal location data being gathered, but also the range of actors with access to it.

While measures can be taken to limit the ease of subsequent use, an individual’s location data gains a significant amount of meaning when it is considered in a wider context. The extent to which anonymised data can be used to infer identity by relating trajectory information with other locations and events raises a pressing concern in location privacy.

I would guess that a significant proportion my own sets of preferences and personalities could be guessed from my life’s trajectory data alone, given sufficient context (which might include the trajectory data of other people, or easily obtained information about places and events). For instance, my own musical taste could probably quite easily be deduced directly from the concerts and festivals I’ve attended over my life, from the concerts and festivals attended by others whose trajectory intersects my own, and indirectly from other inferred personality traits.

As outlined in the reading, the meaning that can be derived from aggregated data may be greatly understated existing privacy policy and regulatory standards. Addressing this issue and limiting growing opportunities for privacy breaches will require case studies that further illustrate the predictive power of location-based data.
-slumley

Laube and Purves (2011) – Temporal granularity and cow trajectory data

December 2nd, 2017

In this article, Laube and Purves explore the influence of temporal scale on the analysis of ecological movement data. In particular, they vary temporal granularity and record the effects on various movement parameters (speed, direction, periodicity) for a high temporal resolution cow trajectory dataset.

Their results show that assessment of these parameters was inconsistent between scales, meaning that the determined speed of the cows depended largely on how finely resolved the timesteps taken were. Thus in general, researchers should be explicit about the temporal scale and range of their analysis; failing to do so could lead to unclear or irreproducible results.

I think in some sense Laube and Purves boil the problem down into two. First, a ‘coastline paradox’ style problem where varying the temporal unit of measurement (e.g. of speed) leads to different speed estimates, though presumably at some point the trajectory lengths tend towards a finite limit in a more meaningful sense than they do for lengths of coastline. Secondly, at smaller temporal scales, uncertainty in GPS measurements become significant. Navigating and accounting for these issues present a challenge and opportunity for GIScientists.
-slumley

Location Privacy and Location-Aware Computing, Duckham and Kulik (2006)

December 2nd, 2017

Duckham and Kulik (2006) introduce the importance of privacy in location-aware computing, and present emergent themes in the proposed solutions to related concerns. In their section contextualizing privacy research, the authors present privacy and transparency as opposing virtues (p. 3). I’m curious about the distinction that would motivate the valuation of one over the other. For instance, many would feel uncomfortable with the details of their personal finances being public (myself included), but would advocate for the openness of business or government finances, or even those of the super-rich. Is power the distinguishing characteristic? Perhaps concerns for person wellbeing or intrusive inferences are less applicable to large organizations, but how do we explain the public response to the Panama or Paradise Papers?

Duckham and Kulik (2006) also posit that greater familiarity and ubiquity of cheap, reliable location-aware technologies will increase public concern for privacy (p. 4). I’m not so convinced–in fact, is it not the opposite? It would seem that during their inception concern for privacy was much higher than it is now. I would argue the pervasiveness of location-aware technologies has generated a reasonable level of comfort with the idea that personal information is always being collected. I would imagine this is evident in the differential use of location-aware technologies in people that have grown up with them.

I appreciated the authors’ discussion of location privacy protection strategies. They provided interesting critique of regulatory, privacy, anonymity, and obfuscation approaches. I would add to the critique of regulatory or policy frameworks based on “consent” that participation in such technologies is becoming less and less optional. Even when participation is completely optional, consent is often ill-informed. It’s clear that the question of privacy in location-aware computing is one with no clear answer.