Archive for March, 2012

Becoming Comfortable with Uncertainty

Monday, March 5th, 2012

In Hunter and Goodchild’s essay entitled “Managing Uncertainty in Spatial Databases”, one statement in particular regarding uncertainty and error in data really hit home: the idea that people don’t understand the error in their data—and I would add, don’t ask about it, either.  This also recalled for me something Ana presented in her talk about LBS—that people don’t always understand or appreciate the data and technologies they are working with today—even perhaps the experts who know the complexities of data and technology that generate information we work with, and potentially take for granted, today.

So for me, amidst all their discussion of identifying, working with, and explaining/understanding error in data, their goal for future research stood out.  “Future error research cannot stay confined to the academic sector and should be conducted jointly with the user community to reflect the need for solving management aspects of the issue”.  The emphasis they place on being able to manage error is also incredibly important, and should also be at the forefront of this integration of research into the user domain, particularly as the user domain does not necessarily mean experts working in the field, but can be any layperson with access to the Internet.

This argument is particularly important as they express in their semi-ironic Figure 1, demonstrating how the experts are the ones who generally know how to deal with data, and what to ask, but don’t need to ask, whereas the layperson does not know how to deal or what to ask, but unfortunately is the one in need of those answers.  When reading Foody’s take on uncertainty, it further highlighted why lack of understanding in users can be negative, outside of creating questionable results—people may choose not to act at all with information they are uncertain about.  As Foody mentions with the global methane sink, without an understanding of how something works, it leads to uncertainty in models and results, and no action being taken.  This also seems a largely important point when arguing for the increased understanding of not only what uncertainties are present, but also what we can do with uncertainty in data.

This particularly reminds me of another class I am taking, in which we are discussing uncertainty in the media with regards to climate change.  Media sources depict scientific knowledge and models to be wrought with uncertainty—and as the public, policy makers, and other “end-users” don’t understand how scientists work with uncertainty in data and models, they are likely to be unreceptive of results and recommendations.

Of particular interest to me, Foody also discusses uncertainty inherent in geographical data, and the issue of zoning and the placement of administrative boundaries that can influence analysis on population data—it appears with uncertainty it is just another problem where assumptions must be made explicit.

sah

Galaxy Beam

Friday, March 2nd, 2012

http://www.guardian.co.uk/technology/gamesblog/2012/feb/27/samsung-galaxy-beam-announced

 

What’s next… phasers?

LBS and User-Centric Design

Friday, March 2nd, 2012

Location-based services (LBS) have already been widely utilized in daily life. By this means, users become both geospatial data providers and the information consumers. In the paper of Jiang et al. 2006, authors point out the LBS should be designed in a user-centric way. As LBS is a developing research field that includes the study of geospatial cyberinfrastructure, information technology, social theories, and data mining, we should take a careful look at the user-centric design in order to improve LBS.

Mobile technologies have contributed a lot geospatial data for LBS. With the development of wireless network, geospatial data, including image data, test message, voice data, and spectral information that are collected with different mobile sensors, can be easily shared over the Internet. But the large data volume becomes another challenge in LBS research; especially of user-centric design. First, not all the data contributed by user are equally useful for knowledge discovery and decision-making. So data mining techniques are necessary and it should also be supported by the geospatial cyberinfrastructure which is not directly visible for end users. Secondly, due to the large scale data and their temporal attributed, real-time computing are usually utilized to guarantee the performance of LBS is satisfying. Moreover, the limited resource of mobile devices require geospatial cyberinfrastructure at the backend to provide functionalities such as data storage, statistical analysis, visualization, to name a few examples here. All those functionalities should be kept transparent to the users, which further complicated the user-centric design research in LBS.

Another point I want to indicate here is the lack of standard criteria for evaluating LBS. As new technologies bring pervasive computing concepts in LBS, how to measure and evaluate the performance of LBS systems are great challenges in the future study.

–cyberinfrastructure

Scale – more complicated than we thought

Friday, March 2nd, 2012

I realised after reading the 3rd page of the article that there actually had not been an attempt to define ‘scale’. No matter, I’m guessing from the reading that it is the name of a class of objects from the ontological perspective (did I get that right?). What I disagree with though (with my own limited experience in remote sensing) is the statement that “pixel size is commonly used as an approximation to the sampling unit size” (page 3). People doing remote sensing a very aware of the limitations of the ‘resolution’ of the data they have, and know that a pixel will often contain the sample plus data about whatever is surrounding it. When trying to extract the signature of an object that is smaller than a pixel, it is unlikely that an analyst would come to the simple conclusion that all the data in the pixel it resides in represents that object.

 

The section on multivariate relationships and other problems with changing components of scale was interesting, but a little worrying. This is one of the reasons why geographers need to exist. The article says that “prior to a field of study, one should check than n provides enough power for detecting the hypothesized pattern, given the anticipated size of the [spatial lag] effect”. What do we do when n is very limited in availability anyway? It’s certainly a good idea to maximise n, but more often than not, data collection is limited by budget, time, and the number of subjects itself. There are other problems with trying to account for all the guidelines in the considerations section.
What really echoed with me was the conclusion, that “there is not one ‘problem of scale’, but many”. What does this mean for those in the general public wishing to do geographic analysis in things such as PPGIS with VGI? What we need is more explicit documentation in methods on all the components of scale. Without this, it will be difficult to comment on the accuracy of studies

 

-Peck

Experimental Design and Scale

Friday, March 2nd, 2012

Dungan et al.’s paper on scale introduced me to one new concept in particular, that some general guidelines could be followed to determine what might be an appropriate scale for a sample or experiment and what conclusions about processes could be drawn from the chosen scale. This concept is particularly important to me as a physical geographer as I have been reading many papers lately for a class on global biogeochemistry where global systems are examined and processes are inferred from experiments of different magnitudes, local and small or combining datasets from many areas. In the remaining readings for this course, I will now be more aware of the scale at which an experiment or study was conducted and will have a better idea when discussing the feasibility extrapolating or interpolating conclusions reached to other scales.

 

-Outdoor Addict

 

Privacy

Friday, March 2nd, 2012

I have heard much about location based services lately and prior to reading this paper had merely thought of it as Google Maps on a smartphone. It was interesting to read more about it and the issues it faces particularly that of privacy and surveillance. As my pseudonym suggests, I enjoy being outside not merely because it is nicer than being inside but partly because nobody knows where I am when I go outside and go hiking or canoeing etc. As mentioned in class, few people recognize location privacy and freedom and fewer still realize is being lost.

Before the advent of cell phones and the internet, if someone wanted to find out where you were going they needed to ask you. Today, they may not need to. They could just see if they have you on Foursquare, if you’ve updated your Twitter location or posted your plans of Facebook. Who says they even need to be good friends to be able to do this? You may have met them once or twice at a school activity etc. and thought you might want to stay in touch with them but they now have access to a huge amount of information about you and particularly your location. This leads to the importance of privacy not only in relation to strangers but perhaps also to acquaintances; you may have met them but do you really want them aware of your every move, literally?

Privacy with respect to strangers, institutions, governments etc. is even harder to obtain as these bodies do not need to know you to obtain your information. In the case of governments and institutions, they may obtain it by attempting to order it be given to them by the companies. In the case of strangers, hacking is not uncommon. It seems to me with one’s location being updated and distributed online or even via a phone, it would be all too easy for someone to follow that person, learn their habits etc. and could be dangerous to their personal security.

The Yao article mentions there are efforts in place to try to create frameworks for increasing security but that these have so far been limited with few studies performed. I feel that much more time and energy should be put into increasing security but that perhaps users should be educated on privacy issues from a young age when they begin using LBS technology so that they are aware of exactly how accessible the information they post online may be to those who are looking for it.

-Outdoor Addict

Disappearing Buildings!

Thursday, March 1st, 2012

The two assigned topics for Friday’s class are relevant to one another. It can be so frustrating when trying to search for a place, store or location on a smart phone. Depending where you are, how zoomed in you are and especially the spelling, the results can have huge amount of variance.

The other day I was searching for The Bell Sports Complex in Brossard, but my phone was incapable of finding my query. I had successfully performed the search before, but for some unknown reason, it no longer existed. Perhaps the disappearance of the Habs’ practice facility could explain their recent woes…

Jiang’s article on LBS provokes a question: Does a feature in a landscape possess different coordinates if it is a point, or does it have different extents (if a polygon) depending on the scale? For example, at a global scale, Montreal might appear as a point feature, but at a larger scale it may instead be a polygon. Does each map of a certain scale possess the address and location for different features? This seems redundant; but perhaps necessary right now. I can imagine that one feature could potentially hold different types of representations. When a certain type of representation is required, it could simply be called upon instead of having repetitions within the database.

I am sometimes concerned about privacy with regards to LBS, but more impressed with how internet searches have become more efficient with the integration of LBS. There are positives and negatives, and at this point, I’m not so concerned with people knowing my exact location. I really enjoy how in GEOG 201, it was mentioned that Google’s goal was to integrate all searches into a map-like interface. Four years later, I can definitely see this as a possibility. It was a little foreign to me at the time, but I am able to see that almost everything has a spatial component to it.

Andrew

Thinking About Scale

Thursday, March 1st, 2012

I agree with cyberinfrastructure and henry miller in their thinking about how scale is presented in the paper written by Dungan et. al. The authors of this paper primarily provide examples from ecology although they do discuss and provide context from other fields. I too think we must be careful in paying attention to what field we are working in when we think about the term scale.

My first introduction to the concept came from a political ecology class I took, where scale could be used outside of just its connotations in physical space and time. Scale, in this context, could be used to think about government, human communities, academic disciplines and more. Of course, political ecologists might often be more concerned with power relationships and how these relationships flow across different scales than we are in this course.

But, since we are looking at this in the context of GIS, I thought one interesting blog post that helps to make one of the same points as the authors of this article might be worth sharing (the pictures do it for me). Scale, just in a physical sense, does matter incredibly when investigating landscapes or in thinking about maps. As a human geographer, the author’s points about the sample size of scale also holds a lot of implications when thinking what is the appropriate scale to study human subjects or their communities on. As cyberinfrastructure notes, we should be mindful of how scale might adjust our methodologies or observations by paying attention to scale itself. But, I would argue that we also need to think about what discipline we are working in (and its definition or varying usages of scale) when we consider scale shifts and how it might affect our research.

-ClimateNYC

Motivations and LBS

Thursday, March 1st, 2012

I really enjoyed reading the article by Jiang and Yao. It was incredibly informative and set up a great framework for me to use when thinking about LBS in the future. The authors mention that “[c]lustering the users in terms of interests, behaviors and personal profiles is an important step towards a better understanding of the users” (715) and discusses grouping users based on the amount of information they desire. I think it would have been insightful to also note the different motivations behind locational-sharing.

A recent New York Times article claims that LBS, despite enthusiasm from investors, have yet to become very popular among users. I think being responsive to users’ motivations for location sharing will be important for LBS gaining more popularity. For instance, an app designed for individuals to share their locations on social networks should understand that one of the reasons people do so is for reputation management. People will share locations that present them in a positive light (e.g. popular restaurants) and keep other locations (e.g. casino) secret. Since individuals are selective about which locations they want their friends to see, this group will not be receptive of an LBS that constant tracks their movements. With regards to the temporal resolution of data, individuals may not want to share details about the duration of their stay at any one location. Other motivations for locational sharing could be fun/gaming and earning “badges” and to discover new places in town (e.g. Yelp).  Further, Lindqvist et al. (2011) “did not find that discounts and special offers [to be] a strong motivator for checking in” for users on Foursquare (a social location-sharing service). However, the authors note that if more business used the service, this could change.

Thus, motivations among naïve users may be useful for developing LBS that are more specialized and responsive to specific needs. These considerations will in turn shed useful insights on the types of privacy settings that will be most appropriate.

Ally_Nash

Lindqvist et al. (2011). I’m the Mayor of My House: Examining Why People Use foursquare – a Social-Driven Location Sharing Application.

The development potential of LBS

Thursday, March 1st, 2012

I liked the article’s overview of LBS – it it consists of, how it’s different from a regular GIS, and what kind of data analysis can be done. There is also a good overview of the issues with using LBS, such as interoperability. Interoperability, I think, is even more important than emphasized in the paper. Although location-based services aren’t restricted to expensive hi-end devices like smartphones (the article doesn’t even explicitly mention LBS in the cellular phone market), it is still fact that certain kinds of phones can benefit more from LBS (i.e. smartphones) than other phones (feature phones + ‘dumb’ phones). This brings to mind a video I just watched where Eric Schmidt of Google gave his views on future developments in internet and telecoms at a couple days ago (not actually directly relevant to LBS). However, he made it clear that, while there are many users with fancy smartphones out there, there are still 5 billion without them, or running on older generation hardware (and networks). I think this is another factor that is holding back the development of LBS. The user base may be large, but still not homogenous, as there is a whole range of devices out there (2G to 4G/LTE). Eric Schmidt gave his opinion that the divide between those that have the cutting edge of devices, and those that don’t, will persist for quite a while longer. If this is the case, LBS will have a tough time being deployed globally, as developers will have to try to design their systems for many different devices, with different operating systems, different processing power, and different capabilities. It may be the case that LBSes for mobile phones will have to be split into hardware specific categories, but since this hardware availability varies with geographic location, there will be a large portion of the world where a certain service will be unavailable. In the final part of his talk, Eric Schmidt answered questions, in which he stated something along the lines of ‘the smartphone of today is the feature phone of tomorrow’. It certainly seems the case in the mobile phone market where certain features are becoming more commonplace, and processing power and memory is constantly increasing. If this is the case throughout the world, then we should be optimistic for the spread of LBS throughout the world.

 

-Peck

Scales in spatial statistical analysis: other definitions, other fields

Thursday, March 1st, 2012

Dungan et al. (2002) are detailed and clear in presenting scales in the field of ecology. Observation scales, scales of ecological phenomena, and scales used in spatial statistical analysis are thoroughly explained, along with their limitations. The three categories that can utilize spatial scale are the studied phenomenon, “the spatial units or sampling units used to acquire information about the phenomenon, and the analysis of the data” (627). When addressing the definitions of phenomena, observations and analysis, we should note that “some of these definitions overlap one another or are ambiguous” (629). In particular, how would be go about determining explicit definitions? Given one of the examples in the article, what would be an explicit definition of grain? The article could have mentioned ways to gain a consensus on the aforementioned definitions. However, the authors do raise awareness of issues regarding the role of scale in spatial statistical analysis scale that have been ignored by the literature, and note that “resolution involves more than observation grain alone” (630).They further state ecologists wrongly utilize scale terminology when applying large scale use to large phenomena and small scale use to small phenomena, observations or analysis. Dungan et al.’s solution is to replace the word ‘scale’ with ‘extent’. Will such changes affect ecologist’s “arbitrary decisions” in their selection of sampling and analysis units? (638)

While the authors do indeed provide a balanced view of scale in spatial statistical analysis by delineating its advantages and limitations, I am curious about scale’s effect on other fields, beyond ecology. Dungan et al. mention that “many ecological attributes can be expected to average linearly…” (631). Although the linear outcome may work for ecologists, how will other fields that will have attributes that will result in non-linear outcomes? How will the data be analyzed? What will be the impact of the modifiable areal unit problem (MAUP)? Outside the field of ecology, complex networks are moving towards the direction of escaping the limitations of scale, where the generative models created aim to comprise of scale-free networks.

-henry miller

LBS, compatibility, and user-friendliness

Thursday, March 1st, 2012

One of the aspects of the article that I found to be most interesting (and relates to my GIScience topic of error and uncertainty) is the mis-matching of geospatial data collected by various individuals or agencies. This also relates to the lecture on spatial cognition, as the data being generated by native and non-native users is greatly influenced by the ways in which spatial knowledge has been gained, whether consciously or sub-consciously. In order to foster LBS activities such as predicting locations, this information is likely to be required to be compatible, which seems like just as challenging of a task as creating universal ontologies.

Catering LBS to the needs of various users is also an interesting and challenging subject, especially as applications and platforms are hindered by features such as small cell phone screens. For various applications, for example, the article notes that a wide array of layers and sources are needed to provide the required information. Also challenging is deciding how to model this information in a user-friendly manner. The article notes that including landmarks, for instance, may be more beneficial than information such as street names. As has been noted in previous posts, the notion of differing needs with regards to presenting information on a screen is also imminent when designing systems for disabled individuals. Since even using a map-based application may be difficult, text-based descriptions may be required instead.

As a final note, Jiang et al. discussed combining the functionality of geometric and symbolic models to include the advantages of both in an LBS. Perhaps this idea is similar to designing road signs, for example, where efforts are made to allow those who may not speak the native language or are illiterate to be able to navigate their way. Like the article notes, no assumptions can be made about a user’s prior knowledge of GIS or spatial environments, which may include vey basic notions such as literacy. As GIS students, it is easy for us to overlook or take for granted the knowledge we have gained through our education, so being able to understand the needs of others will certainly be a challenge.

– jeremy

LBS and Naive Users (A.K.A. Me)

Thursday, March 1st, 2012

I must say I appreciated Bin Jiang and Xiaobai Yao’s article “Location-based services and GIS in perspective” a great deal for the myriad ways it helped to explain LBS technology in light of GIS science’s research agenda, particularly given how ubiquitous they are in our everyday lives right now. The key section, to me at least, is where the authors argue that these technologies tend to be “generally oriented to naive users” (719) because potentially everyone might be a user some day. In a nutshell, that naive user is me but with one important caveat. I do not own an IPhone, tablet, IPad or any other generally accepted form of LBS technology. While I’d like to think I’m relatively sophisticated in using modern, online technology, I simply can’t bring myself to buy any kind of tablet because I’m not able to distinguish how my using it would be different from using my computer. Generally, as cell phones go, I’m that guy who walks into the store and demands the cheapest, most-unbreakable phone I can get. Perhaps I’m old, but a phone should be a phone and nothing more, by my way of thinking.

So I found this paradigm of the naive user engaging with LBS technology particularly interesting when the authors got into discussing how research into “spatial ontologies”  and “geographic representation” could be closely tied into work on LBS platforms. The authors approach it from the perspective that such research can help to “set up a common ontology for LBS for knowledge sharing among diverse users” (718). This might be one direction such a flow could be viewed: previously developed ontologies of geographic space shaping the manner in which LBS networks/devices display such information. But, I would think such a flow might move in the opposite direction too, in that many LBS users might influence definitions of geographic space according to how they use their devices. As the authors note, aspects of spatial cognition will be very important to LBS device design (719). Or, put simply, naive folks like me will want simple ontological definitions so they can understand/use these devices better.

But, let’s remember to put this in perspective. Not everyone uses these devices the same way and people like me have taken themselves out of the game entirely. So, how do designers define ontologies that fit all of the diverse users around the globe? I know interoperability remains an important idea as we discussed with Renee’s talk about ontologies, but at what cost? Take this example: A little while ago, a friend took me on a kayaking trip around the Boston, MA harbor islands. He did not bring a map. After a long day, we found ourselves still on the water in the dark searching for the island where we could camp. We knew we were close but his IPhone was on the blink – at least as far as its star charts, GIS, and map technologies were concerned. Needless to say, he was not pleased. For my part, I found it amusing he thought such devices would work on the ocean (albeit still within 5 miles of shore).

Perhaps just a technological infrastructure issue – but the point is still the same. If we’re thinking about defining standards for the information these devices display, what happens if our standards disenfranchise kayakers? More to the point, what about users in Africa who find landmarks such as a neighbor’s field more useful than street grids with names? The authors touch on this idea, but how do we allow naive users to generate data and give input on the ways these devices work as they become yet even more commonplace across the globe.

-ClimateNYC

DISCLAIMER: My parents do both own complicated, new-fangled cell phones that allow many of these LBS functions. And, yes, I have used them many times and helped my parents figure out how to use them – since I somehow am a bit more adept than they.

 

 

Clarify “Scale” in Different Research Domain

Thursday, March 1st, 2012

In the paper of Dungan et al. 2002, the definition of the terminology “scale” is examined in spatial research domains. They explore “scale” with the phenomenon being studied, the spatial unit or sampling unit, and data analysis. Within different research domains, they find different synonyms for “scale”, including extent, gain, resolution, lag, support and cartographic ratio. Case studies are provided to illustrate different definition of “scale” in different research topics. Modifiable Area Unit Problem (MAUP) is identified, and authors present several suggestions to avoid it.

Most of the examples in this paper come from ecology studies, so the diversity of “scale” is not fully explored. They have mentioned “scale” in remote sensing, and refer it as the synonym of “resolution”. But “resolution” in remote sensing is involved with spatial resolution, spectral resolution and temporal resolution. In image data analysis, the word “scale” is more often utilized as statistical scale, which is related to the analysis unit rather than the observational or sampling unit. For geospatial database design and implementation, the word “scale”, or “large-scale” have significantly different meaning. The large scale data do not only mean huge volume, but also heterogeneity (e.g., different spectral and spatiotemporal resolution) and complexity (e.g., data with different format, noisy rate, and distributed storage) as well. Therefore, I agree with the authors in this paper, that “scale” should be specified with respect to the context that it is used.

Different scales give us different approaches to study our targets. By changing the scale, we actually change our methodology and observation methods. Therefore, more attention should be given to “scale “itself, not the definition.

–cyberinfrastructure