OUseful.Info, the blog…

Whilst playing with some Google maps last night, I noticed a new control:

Click it, and the browser throws up a request:

For those of you who haven’t seen this sort of thing before, the latest browsers come complete with location aware browsing. In the case of my browser, “Firefox gathers information about nearby wireless access points and your computer’s IP address. Then Firefox sends this information to the default geolocation service provider, Google Location Services, to get an estimate of your location.”

If you’re using a mobile phone, additional cues ares available, such as a GPS fix if your phone is GPS enabled, and cell tower triangulation, where the phone’s location can be detected not only from the current cell the phone is registered with, but also from the signal strength of surrounding cells.

If you accept the location finding, the new Google map control turns out to be a blue dot control…

You can revoke the location aware privilege by going to the site you granted access to, selecting “Page Info” from the Firefox tools menu, and then tweaking the Location Awareness setting:

Adding location awareness to a web page is trivial (e.g. Where are you? Find out with geolocation in Javascript) and is something I suspect that Facebook will soon have a privacy setting for…;-)

Anyway, in order for wifi network detection to be usable, a service is required that can map a network identifier onto a location. Skyhook Wireless is one provider of this service (I don’t think Google has acquired it – yet…), but Google also appears to be building its own…

There are several ways for Google to do this, of course…. If you have an Android phone, then it’s in principle possible for the phone to reconcile GPS data with cell tower and wifi network identifers and signal strengths. And the Google Streetview car? Well it appears that it doesn’t just collect imagery… On Google Street View Car Logging Wifi Networks: “Google’s roving Street View spycam may blur your face, but it’s got your number. The Street View service is under fire in Germany for scanning private WLAN networks, and recording users’ unique Mac (Media Access Control) addresses, as the car trundles along.” In the past, of course, there have also been privacy concerns about Google Street View capturing faces and car number plates. (See also: Large-scale Privacy Protection in Google Street View [PDF]).

Ever one to take an idea and run too far with it, I had a little think around what other sorts of “assist” information Google might be able to capture from Street View. So for example, in December last year (2009) it was announced that Google takes another stab at QR codes. Will it work this time?: “Google announced a broad plan to introduce QR code stickers in the windows of over 100,000 local businesses nationwide.” Hmm…so that means if Street View captures the QR code, it can then reconcile that location with your business…

(Street View captured QR-codes also provides a launchpad for augmented reality ads in Google Maps and Google Earth, e.g. by using the QR-code as the augmented reality registration image. See for example Real-Time Ads Coming to Google Street View?.)

Something else that was announced this week – Google Cloud Print, in which printers become accessible, and fax machines can be laid to rest…

Our goal is to build a printing experience that enables any app (web, desktop, or mobile) on any device to print to any printer anywhere in the world.

The Goog will quickly work out where in the world those printers are, of course… (I can’t wait to see a “Printers near me” option appearing in context menus… Err…;-)

(Just in passing, this also caught my eye this week: Digital Photocopiers Loaded With Secrets. In short, digital photocopiers are scanners, with hard drives. So assuming that you know all those stories about sensitive information leaking from organisations via hard drives on scrapped PCs, well, err..? What happened to your last workplace photocopier?)

Okay, enough loose threads there for you to weave into your own nightmare scenario… @andysc suggested this was all getting a bit like Halting State, so I’m going to track that book (which is new to me) down right now…

See also: So What Do You Think You’re Doing, Sonny?

Although on a day to day basis I’m a Mac user, every so often I need to dip into the Windows virtual machine on my laptop. This generally fills me with fear and trepidation, because as an infrequent Windows user, whenever I do go over to the dark side I know my internet connection will grind to a halt and I will get regular requests to restart the machine as Windows goes into update mode. In a similar vein, on a day to day basis it’s Twitter that meets my social web needs. But on the rare occasions I go into Facebook, I’m also filled with dread. Why? Because there is frequently a new privacy minefield to negotiate (e.g. Keeping Your Facebook Updates Private).

Over the last few days, there’s been a Facebook developers conference, so I thought it worth checking in to see what new horrors have been released; and here’s what I saw today:

Hmm…

So Facebook makes it easy for website owners to help you “tweet” a link to your Facebook stream… (I wonder, does this also work as a social bookmarking service? Can I browse through the links I’ve Liked?

Ah – according to Deceiving Users with the Facebook Like Button, it appears that “Removing the feed item from your newsfeed does not remove your like — it stays in your profile. You have to click the button again to remove the ‘Like’ relationship.” So it could be used as a social bookmarking service, of a sort. Or at least a Facebook equivalent to “favorited” websites in your browser.

As you might have guessed from the previously linked to post, all may not (yet) be well with the Liked implementation though – because it seems that it’s possible to add a “Like” link on one page that actually Likes a page on another website. Which reminds me a little of phishing…

So, what other goodness (?!) does Facebook have in store for us?

Instant personalisation, hmm…? So if I go to Pandora, say, it can trawl my Facebook profile, decide from my Likes and updates that I’m a goth hippy groover, and generate a personalised radio station for me jus’ like that? The oo’s have it… (ooh…, cool… or spooky…?;-)

And guess what, Facebook have thoughtfully opted me in to that service, without me having to do anything, and without even forcing me to notice (I didn’t have to follow the link on the home page to read the new service announcement; and for mobile users, I wonder if any of the Facebook apps tell the users that they’ve been opted in to this new way of giving their personal data to third parties…?)

I think I’ll click here:

I think I’ll untick…

Am I sure…? Err, yes… Confirm.

But what does this mean…?

Please keep in mind that if you opt out, your friends may still share public Facebook information about you to personalize their experience on these partner sites unless you block the application.

Hmmm, I think I’ll Learn More… (do you ever get the feeling you’ve ended up in one of those Create Your Own Adventure style games, only for real… Is this Brazil, or a Trial?

Err, right…

I guess this is the one:

What data is shared with instantly personalized partner sites?
When you and your friends visit an instantly personalized site, the partner can use your public Facebook information, which includes your name, profile picture, gender, and connections. To access any non-public information, the website is required to ask for you or your friend’s explicit permission.

Or is that “When you or your friends visit…”? That is, if my friend visits Pandora and goes for instant personalisation, can Pandora use my friend as a vector to grab my public information? A question that now follows is – can Pandora identify my Facebook identity through some mechanism or other (e.g. Facebook set cookies?) and reconcile that with what it has learned about me from my friends who have opted in to personlisation features. And if so, could it then offer me personalisation services anyway, even though I opted out on Facebook…?

I’m still unticking… because as Facebook adds partners, I probably won’t pick up on it…

So, do I dare walk up the Facebook Privacy tree…? Let’s go up to the Privacy Setting page:

So here’s the Profile Settings control panel:

Hmmm… there’s a link there to Application Settings, which I don’t think appears on the Privacy settings page. Where does it go?

I’m not sure I understand everything in that drop down menu…?

How about the Contact settings?

Search?

Blocking?

Sheesh.. So here are the tabs that I have to work through:

Many of the pages only require setting a simple drop down box (though thinking through the implications, and what relates to what may be comples); but there are also quite a few that offer “Edit Settings…” links, and I suspect that some of those open up into rather more involved dialogues…

I reckon you could easily spend at least 1 week/10 hours of a 10 point short course just looking at Facebook privacy settings, and trying to think through what the implications are…

Which brings to mind the Facebook network visulisation I started working on with Gephi… Could we use visualisation tools to highlight who in your Facebook network can see what given your current privacy settings? Methinks there’s an app in that…

PS popping back in to Facebook just now to delete most of the apps I’m signed up to, I noticed on the “click here” page linked to above the option:

What your friends can share about you
Control what your friends can share about you when using applications and websites

Clicking through to Edit Settings, here’s what I see:

[Since grabbing that screenshot, I've unchecked all those boxes...]

I’ll spell out the text for you:

What your friends can share about you through applications and websites

When your friend visits a Facebook-enhanced application or website, they may want to share certain information to make the experience more social. For example, a greeting card application may use your birthday information to prompt your friend to send a card

If your friend uses an application that you do not use, you can control what types of information the application can access. Please note that applications will always be able to access your publicly available information (Name, Profile Picture, Gender, Current City, Networks, Friend List, and Pages) and information that is visible to Everyone

So… if i don’t take steps to protect my information, then my friends can give access to my presence, videos, links, photos, videos and photos and tagged in, my birthday, hometown etc etc to third party applications? Does that mean if I have various privacy settings set to share with friends only, they can still share the information on to third parties I did not anticipate seeing the data?

In the following set up, who can see photos and videos of me?

Answers in the comments please… If anyone’s done the experiments to see just how the various previous setting inter-relate, I’d love to see a write-up. I’m also thinking: maybe Facebook should be required to publish a logical model of what’s going on? (Are there logics of privacy? You could probably get somewhere close using epistemic logic?)

(It’s all a bit like writing legislation that says that as yet unspecified powers will be given to a Minister, who may then devolve those powers to others…;-)

PPS a page I didn’t link to/show a screengrab of but should have included is the Applications page (this is not under the privacy settings. You can find it here: http://www.facebook.com/#!/editapps.php?v=allowed

If you don’t use an app, particularly an external one, I suggest you delete it…

[UPDATE: Why I Joined the Facebook Privacy Changes Backlash...]

A couple of days ago, I picked up via a post on the Guardian Datablog a cluster map visualisation by the Public Whip folk comparing how MPs from the various parties have voted over the last few Governments: MP vote map (data).

The 2D chart shows clustered voting behaviour in Parliamentary votes between recent elections, showing who voted with whom (e.g. did the LibDems tend to vote with Labour MPs, or Conservative MPs?).

Ever a literalist, I thought I’d have a crack at the data myself, and plot some simple coloured matrix charts of MPs vs. vote, using colour to denote whether or note the MP voted in favour of the motion, or against it.

So for example, for the 2005-2010 period, I get the following:

The top block shows Labour MPs, then Lib Dems, then Conservative MPs and finally MPs from the other parties. The x-axis is the vote, with (I think) more recent votes to the left; individual MPs go down the y-axis. Looking at a line across the screen gives the voting record for a particular MP; looking at a line going down the screen shows how folk voted on a particular vote.

Where there are long horizontal black lines showing, this is identifies MPs who were absent from votes over that period of time. If you have good eyesight, looking down the votes, we can see whether or not the parties voted the same way. I have put in a little bit of interactivity to allow exploration of the data, but I think it also needs x/y magnification to better show the votes for the selected vote and MP:

To try to make things a little easier to see, here’s a view of the map showing MPs who were marked by the Public Whip as absent from a vote (white is absent);

Hover the mouse cursor over one of the lines shows Tony Blair as being largely absent (as you might expect). A distinct white line going down the screen shows that very few people attended the vote. I need to rethink this interaction, I think, maybe showing the votes that an MP did vote at when you highlight them, and using red/green colour to show how they voted.

The next view attempts to show whether or not a particular MP voted with the majority vote of their party…

So for example, looking across the diagram to find lines (= regular dissenters), I can pick out Jeremy Corbyn, Alan Simpson and Kenneth Clarke, which the Public Whip also sees as voting against the majority view of their party. Where there are significant numbers voting against the majority view of the party, I’m guess that’s a free vote…? Or, err, there’s something a little buggy going on in the code…:-(

The app was written in Processing; for what it’s worth, I posted an edit or two ago of the code code as a gist on github.

PS I just updated the info panel to provide a little bit more detail about how a vote went:

The bottom line shows the turnout for the vote, the overall majority (-ve number means the vote wasn’t passed), then the ayes/noes for each party. If this info doesn’t match the actual vote record, I know I have a bug…:-) (or is that :-(?

On Wednesday, transport willing, I’ll be giving a short presentation at an East of England Imnformations Services Group event:

Whilst preparing the slides, I listened in to Martin Bean’s opening keynote from JISC2010, and was interested to hear what he had to say about libraries:

That is, folk are gonna need help with sensemaking around information and with identfiying trusted [trustable?] content.

I had intended to put together a talk about the challenges faced by the OU library, as I see them, as it starts to offer a comprehensive digital library service for our students; but the VC’s talk got me thinking again about some of the issues I touched on in my Arcadia brown bag lunch talk about the skills training gap that I think is building up around digital tools:

Anyway, here’s a preview of my slides for Wednesday (subject, as ever, to change…;-)

(UPDATE, post presentation: a couple of folk commented on the slide aesthetic – it’s inspired in part by the Presentation Zen approach (blog), in part by Lawrence Lessig. As far as the Digital Economy Bill/Act goes, here’s a summary. And for Doctorow on book ownership, listen here.)

The content diverges somewhat from the title (oops!) but I feel the need to have another crack at exploring what exactly are the skills I think we’re failing to articulate…

As ever, it’s rich in images that don’t make a lot of sense without my commentary. I also toyed with the idea of embedding a few audio and video clips in the presentation, but as time is tight, I think I’ll omit probably have to omit those on the day:-(

One of the clips I had thought of using was Martin Bean’s quote embedded above. Another was from a recent TEDxNYED talk by Jeff Jarvis (via @ajcann) in which he talks about the move educators – like journalists – may have to make towards a curatorial role.

For libraries, too, there is need to consider the new curatorial role of the library (e.g. as recently observed by Lorcan Dempsey: Lam-inating libraries…). But maybe more important is the help that librarians can give to academics, and researchers, who are building their own collections, and wanting to curate their own “exhibitions”?

(Just by the by, I’ve started putting together the images I use in my presentations in flickr galleries. In part, this means I have ready access from source to images I’ve used before if I want to use them again… I’m also toying with the idea of trying to annotate the images in the gallery with “presenter notes” or “presentation design notes” as a way of capturing some of the things I was thinking about/looking for as I was selecting the images. If I was doing an Art GCSE, I guess this would correspond to my notebook…)

One of the reasons I considered adding the audio clips to the presentation was because they were to hand and I heard things in them potentially relevant to, and reusable in, the presentation I was preparing. (The use of the clips would also slow the presentation down a little – something I’m looking for strategies to help me with. Fewer slides may help here, of course…!;-) To make (re) use of them, I wired the headphone out to the audio in on my laptop, and played through the relevant parts of the original videos whilst capturing the audio track using Audacity. A little bit of editing in that environment cropped the audio clip to just the bit I needed, and also allowed me to tidy it up a little (removing ums and ahs, for example). For hosting purposes, I’ve used Audioboo. I’m not sure this is really in the spirit of Audioboo, but again, it was a pragmatic choice;-) Now I haven’t received any training in this (as any audiophile will probably be able to tell you!) but it got the job sort of done…

So, is that a skill the library can – or should – help me with, if required? In the OU’s case, I think getting help with that sort of activity would fall under the Digilab remit.

At the very least, is/could/should it be the role of the library to help me develop effective strategies for discovering audio content (nothwithstanding what the VC had to say about moving on from search and discovery)? Discovering audio content from OER repositories, maybe?

And what about help or advice on producing visualisations, such as visualisation of volcanic ash data from official advisory notes? Would that count too? (That was a request typical of the ones I receive on a weekly basis from various parts of the OU…) I captured my hacked attempt at working through that problem in the post Steps Towards a Volcanic Ash Advisory Google Maps Mashup Using Met Office Data, which also includes several bad assumptions I made in the original version of the post, so maybe I should pick through that to identify some of the skills involved?

Other Martin’s been at it again, this time posting JISC10 Conference Keynotes with Twitter Subtitles.

The OU’s VC, Martin Bean, gave the opening keynote, and I have to admit it really did make me feel that the OU is the best place for me to be working at the moment :-)

… though maybe after embedding that, my days are numbered…? Err…

Anyway, I feel like I’ve not really been keeping up with other Martin’s efforts, so here’s a quick hack a placemarker/waypoint in one of the directions I think the captioning could go – deep search linking into video streams (where deep linking is possible).

Rather than search the content, we’re going to filter captions for a particular video, in this case the twitter caption file from Martin (other, other Martin?!) Bean’s #JISC10 opening keynote. The pipework is simple – grab the URL of the caption file and a “search” term, parse the captions into a feed with one item per caption, then filter on the caption content. I added a little Regular Expression block just to give a hint as to how you might generate a deeplink into content based around the tart time of the caption:

You can find the pipe here: Twitter caption search

One thing to note is that it may take some time for someone to tweet what someone has said. If we had a transcript caption file (i.e. a timecoded transcript of the presentation) we might be able to work out the “mean time to tweet” for a particular event/twitterer, in which case we could backdate timestamps to guess the actual point in the video that a person was tweeting about. (I looked at using auto-genearated transcript files from Youtube to trial this, but at the current time, they’re rubbish. That said, voice search on my phone was rubbish a year ago, but by Christmas it was working pretty well, so the Goog’s algorithms learn quickly, especially where error signals are available. So bear in mind that if you do post videos to Youtube, and you can upload a caption file, as well as helping viewers, you’ll also be helping train Google’s auto-transcription service (because it’ll be able to compare the result of auto-transcription with your captions file…. If you’re the Goog, there are machine learning/supervised learning cribs everywhere!))

(Just by the by, I also wonder if we could colour code captions to identify in a different colour tweets that refer to the content of an earlier tweet/backchannel content, rather than the foreground content of the speaker?)

Unfortunately, caption files on Youtube, which does support deep time links into videos, only appear to be available to video owners (Youtube API: Captions), so I can’t do a demo with Youtube content… and I so should be doing other things that I don’t have the time right now to look at what would be required deeplinking elsewhere…:-(

PS The captioner tool can be found here: http://www.rsc-ne-scotland.org.uk/mashe/ititle/

Martin Hawksey, whose work this is, has described the evolution of the app in a series of several posts here: http://www.rsc-ne-scotland.org.uk/mashe/?s=twitter+subtitles

Another Formula One Grand Prix race weekend, another chance to tinker with some F1 visualisations, this time from China. Not much new this week – it’s been more a case of me making a start on tidying up my scripts, but I have started trying to think about driver comparisons.

So for example, on the driver DNA charts, we see a difference in gear change behavior between Button and Hamilton about 40% of the way into the track:

We can see this a little more clearly on a geographical projection of the gear change data (the tracks are offset from each other to aid visualisation):

We can also see some different in rThrottlePedal behaviour:

Okay, that’s enough for just now – back to coding up some KML views for Google Earth ;-)

As ever, thanks to @bencc for grabbing the data. For more posts in this series, see: OUseful f1data.

Sigh…;-)

Hi Tony,
In looking for authoritative news on the cloud about to tr-ash my holiday, I found this advisory:

http://www.metoffice.gov.uk/aviation/vaac/vaacuk.html

There’s a string of coordinates which appear to mark the extent of the cloud at “FL200” (20000 feet?). E.g. N6343 W01935 is 63.43N 19.35W.

It looks ripe for your skills, and if you could get a map and a how to …

Don’t you realise it’s a race weekend – and if I tinker on such a weekend, I tinker F1data?!;-)

Okay – so here’s a half hour hack (I timed it)…

The advisory data from the Met Office looks like this:

Rather than mess around with any scraping, I just copies and pasted some of the data into a text editor (I use TextWrangler on a Mac) and ran a few regular expressions over it. Starting at the bottom of the list:

- remove end of line characters and replace them with a space;
- remove the “-” and any whist space around it and replace it with a return (new line) character;
- replace the space with a tab character.

The result of the regular expression processing is a two column tab separated list of co-ordinates.

These can then be copied and pasted into a spreadsheet. For rapid prototyping purposes, I pasted the data into a Google spreadsheet because I know I can get a access to a CSV output from there, and I also know that I can get access to a map widget that will plot markers given lat/long data in that environment.

BIG OOPS… The next step was to decode the position data. How to read a Volcanic Ash Advisory gave a couple of clues, and a quick test suggested the data is direction, degrees, minutes, seconds concatenated. I’m guessing that in the general case the degrees are always two digits, the minutes one or two digits and the seconds zero or two digits but in the data I looked at the length was always 5 characters for latitude (dDDMM), 6 for longitude (dDDMSS), so I just worked with those fixed lengths.

Most of the mapping tools I use require lat/long co-ordinates in a decimal format, so a quick check of Stack Overflow turned up a function to convert from degrees, minutes, seconds to the decimal version (Converting latitude and longitude to decimal values).

UPDATE: I think the data format is actually just a decimal format to 2 dp. So the above and code below is all, in this case, nonsense… but I’m going to leave the content here anyway…

I then used a variant of this code to hack a formula using Google Apps script to run the conversion:

Using the apps script function I had defined as a spreadsheet formula, I could convert the lat/long data in the format provided by the advisory note into the more typical digital representation. Highlighting the converted lat/long data and Inserting a Google Maps Gadget gave me a mapped preview over the data.

Here’s the code (needs generalising bearing in the 1/2 digits for minutes; I had a problem with substring (not sure what – I only ever got one character out) which is why I used substr for the parsing):>

//http://stackoverflow.com/questions/1140189/converting-latitude-and-longitude-to-decimal-values

/***************************************
*** BROKEN CODE - left in for reference purposes only ***

****************************************/
function ConvertDMSToDD_BROKEN_STUPID(degrees, minutes, seconds, direction) {
    var dd = degrees + minutes/60 + seconds/(60*60);

    if (direction == "S" || direction == "W") {
        dd = dd * -1;
    } // Don't do anything for N or E
    return dd;
}

function ParseDMS(input) {
  var parts = [];
  if ((input.substring(0)=="N")||(input.substring(0)=="S")){
    parts[0]=parseInt(input.substr(1,2));
    parts[1]=parseInt(input.substr(3,2));
    parts[2]=0;
    parts[3]=input.substring(0);
  } else {
    parts[0]=parseInt(input.substr(1,2));
    parts[1]=parseInt(input.substring(3));
    parts[2]=parseInt(input.substr(4,2));
    parts[3]=input.substring(0);
  }
  var coord = ConvertDMSToDD(parts[0], parts[1], parts[2], parts[3]);
  return coord;
}

You can see the [UPDATE: corrected] spreadsheet here: Volcanic Ash Advisory mapping demo.

I replaced the lat/long conversion formula with one that:
- adds a decimal place after the first two digits;
- adds a minus sign for W/S.

Here’s the corrected formula:

function ParseDMS(input) {
  var parts = [];
  parts[0]=input.substring(0);
  parts[1]=input.substr(1,2)+'.'+input.substr(3);
  var coord = parseFloat(parts[1]);
  if ((parts[0]=='S')||(parts[0]=='W')) coord=coord*-1;
  return coord;
}

So what would be next?

- tidy up the lat/long conversion code so that it works in general case;
- find a way of pulling data into the spreadsheet live.

It would also be interesting to try to take into account altitude data, and then view the data in 3D in something like Google Earth. A heat map view rather than separate markers might also be fun to do (e.g. using HeatMapAPI).

But for now, back to the weekend…

The eagle eyed among you may have noticed a change to the domain part of the OUSeful.info URL. I took the plunge, and paid for a WordPress upgrade, and now I have a OUseful.info subdomain – http://blog.ouseful.info – acting as home to the OUseful.info blog.

Whilst the blog is still hosted on WordPress – and the original URLs should all still work – this is the first step in taking ownership of how my web content is resolved…

The mapping is achieved by adding a CNAME mapping to the DNS settings for ouseful.info so that blog.ouseful.info maps onto ouseful.wordpress.com. (This is achieved via the DNS administration control panel provided by my host). WordPress describe the process here: Domain Mapping » Map a Subdomain. The WordPress Primary Domain setting then determines which domain appears as the default in the browser address bar.

Now if only Automattic provided a tool to rewrite all the links in my previous posts that point to ouseful.wordpress.com so they point to blog.ouseful.info…

And what I suppose I need to do next on the feed subscription front is find a way of taking ownership of http://feeds.feedburner.com/ouseful so that folk can subscribe to that feed (with its attendant statistics) through the address feed.ouseful.info…. Anyone know if this is possible?

PS Ah, to answer my own question, Feedburner MyBrand appears to be what I need (e.g. see MyBrand Overview). If all’s gone correctly, then as soon as my CNAME mapping from feed.ouseful.info feeds.ouseful.info to Feedburner propagates, it should all work smoothly and the OUseful.info blog feed should be available from http://feeds.ouseful.info/ouseful…

A couple of weeks ago, I came across Gephi, a desktop application for visualising networks.

And quite by chance, a day or two after I was asked about any tools I knew of that could visualise and help analyse social network activity around an OU course… which I take as a reasonable justification for exploring exactly what Gephi can do :-)

So, after a few false starts, here’s what I’ve learned so far…

First up, we need to get some graph data – netvizz – facebook to gephi suggests that the netvizz facebook app can be used to grab a copy of your Facebook network in a format that Gephi understands, so I installed the app, downloaded my network file, and then uninstalled the app… (can’t be too careful ;-)

Once Gephi is launched (and updated, if it’s a new download – you’ll see an updates prompt in the status bar along the bottom of the Gephi window, right hand side) Open… the network file you downloaded.

NB I think the graph should probably be loaded as an undirected graph… That is, if A connects to B, B connects to A. But I’m committed to the directed version in this case, so we’ll stick with it… (The directed version would make sense for a Twitter network (which has an asymmetric friending model), where A may follow B, but B might choose not to follow A. In Facebook, friending is symmetric – A can only friend B if B friends A.

(Btw, I’ve come across a few gotchas using Gephi so far, including losing the window layout shown above. Playing with the Reset Windows from the Windows menu sometimes helps… There may be an easier way, but I haven’t found it yet…)

The graph window gives a preview of the network – in this case, the nodes are people and the edges show that one person is following another. (Remember, I should have loaded this as an undirected graph. The directed edges are just an artefact of the way the edge list that states who is connected to whom was generated by netvizz.)

Using the scroll wheel on a mouse (or two finger push on my Mac mousepad), you can zoom in and out of the network in the graph view. You can also move nodes around, view the labels, switch the edges on and off off, and recenter the view.

Not shown – but possible – is deleting nodes from the graph, as well as editing their properties.

You can also generate views of the graph that show information about the network. In the Ranking panel, if you select the Nodes tab, set the option to Degree (the number of edges/connections attached to a node) and then choose the node size button (the jewel), you can set the size of the node to be proportional to the number of connections. Tune the min and max sizes as required, then hit apply:

You can also colour the nodes according to properties:

So for example, we might get something like this:

Label size and colour can also be proportional to node attributes:

To view the labels, make sure you click on the Text labels option at the bottom of the graph panel. You may also need to tweak the label size slider that’s also on the bottom of the panel.

If you want to generate a pretty version of the graph, you need to do a couple of things. Firstly, in the layout panel, select a layout algorithm. Force Atlas is the one that the original tutorial recommends. The repulsion strength determines how dispersed the final graph will be (i.e. it sets the “repulsive force” between nodes); I set a value of 2000, but feel free to play:

When you hit Run, the button label will change to Stop and the graph should start to move and reorganise itself. Hit Stop when the graph looks a little better laid out. Remember, you can also move nodes around in the graph as show in the video above.

Having run the Layout routine, we can now generate a pretty view of the graph. In the Preview Settings panel on the left-hand side of the Gephi environment, select “Show Labels” and then hit “Refresh”:

In the Preview panel, (next tab along from Preview Settings), you should see a the prettified, 3D layout view:

Note that in this case I haven’t made much attempt at generating a nice layout, for example by moving nodes around in the graph window to better position them, but you can do… (just remember to Refresh the Preview view in the Preview Settings… (There must be a shortcut way of doing that, but I haven’t found it…!:-(

If you want to look at who any particular individual is connected to, you can go to the
Data Table panel (again in the set of panels on the right hand side, just along from the Preview tab panel) and search for people by name. Here, I’m searching the edges to see who of my Facebook friends a certain Martin W is also connected to on Facebook;

It’s easy enough to highlight/select and copy these cells and then post them into a spreadsheet if required.

So that’s step 1 of getting started with Gephi… a way of using it to explore a graph in very general terms; but that’s not where the real fun lies. That starts when you start processing the graph by running statistics and filters over it. But for that, you’ll have to wait for the next post in this series… which is here: Getting Started With Gephi Network Visualisation App – My Facebook Network, Part II: Basic Filters

Over the last few weeks, there has a been a smattering of challenges to the Linked Data community baiting them to demonstrate some of the utility of the Linked Data approach (e.g. A Challenge To Linked Data Developers (followed up in Response To My Linked Data Challenge) and Linked Data: my challenge, with some other possibilities here: 10 Ideas For Web of Data Apps).

So here’s my challenge, inspired by the #leadersdebate last night:

.

That is: each party should be required to tweet a link to #datagovuk sparql query to justify every “factual” claim they make.

For example – can someone write me a Linked Data query to show how much is spent by the government on UK education quangoes?

PS doing something similar for any claims made in the manifestos should also count…