Tag Archives: tony hirst

When information is power, these are the questions we should be asking

Various commentators over the past year have made the observation that “Data is the new oil“. If that’s the case, journalists should be following the money. But they’re not.

Instead it’s falling to the likes of Tony Hirst (an Open University academic), Dan Herbert (an Oxford Brookes academic) and Chris Taggart (a developer who used to be a magazine publisher) to fill the scrutiny gap. Recently all three have shone a light into the move towards transparency and open data which anyone with an interest in information would be advised to read.

Hirst wrote a particularly detailed post breaking down the results of a consultation about higher education data.

Herbert wrote about the publication of the first Whole of Government Accounts for the UK.

And Taggart made one of the best presentations I’ve seen on the relationship between information and democracy.

What all three highlight is how control of information still represents the exercise of power, and how shifts in that control as a result of the transparency/open data/linked data agenda are open to abuse, gaming, or spin. Continue reading

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Merging Datasets with Common Columns in Google Refine

It’s an often encountered situation, but one that can be a pain to address – merging data from two sources around a common column. Here’s a way of doing it in Google Refine…

Here are a couple of example datasets to import into separate Google Refine projects if you want to play along, both courtesy of the Guardian data blog (pulled through the Google Spreadsheets to Yahoo pipes proxy mentioned here):

University fees data (CSV via pipes proxy)

University HESA stats, 2010 (CSV via pipes proxy)

We can now merge data from the two projects by creating a new column from values an existing column within one project that are used to index into a similar column in the other project. Looking at the two datasets, both HESA Code and institution/University look like candidates for merging the data. Which should we go with? I’d go with the unique identifier (i.e. HESA code in the case) every time…

First, create a new column:

Now do the merge, using the cell.cross GREL (Google Refine Expression Language) command. Trivially, and pinching wholesale from the documentation example, we might use the following command to bring in Average Teaching Score data from the second project into the first:

cell.cross("Merge Test B", "HESA code").cells["Average Teaching Score"].value[0]

Note that there is a null entry and an error entry. It’s possible to add a bit of logic to tidy things up a little:

if (value!='null',cell.cross("Merge Test B", "HESA code").cells["Average Teaching Score"].value[0],'')

Here’s the result:

Coping with not quite matching key columns

Another situation that often arises is that you have two columns that almost but don’t quite match. For example, this dataset has a different name representation that the above datasets (Merge Test C):

There are several text processing tools that we can use to try to help us match columns that differ in well-structured ways:

In the above case, where am I creating a new column based on the contents of the Institution column in Merge Test C, I’m using a couple of string processing tricks… The GREL expression may look complicated, but if you build it up in a stepwise fashion it makes more sense.

For example, the command replace(value,"this", "that") will replace occurrences of “this” in the string defined by value with “that”. If we replace “this” with an empty string (” (two single quotes next to each other) or “” (two double quotes next to each other)), we delete it from value: replace(value,"this", "")

The result of this operation can be embedded in another replace statement: replace(replace(value,"this", "that"),"that","the other"). In this case, the first replace will replace occurrences of “this” with “that”; the result of this operation is passed to the second (outer) replace function, which replaces “that” with “the other”). Try building up the expression in realtime, and see what happens. First use:
toLowercase(value)
(what happens?); then:
replace(toLowercase(value),'the','')
and then:
replace(replace(toLowercase(value),'the',''),'of','')

The fingerprint() function then separates out the individual words that are left, orders them, and returns the result (more detail). Can you see how this might be used to transform a column that originally contains “The University of Aberdeen” to “aberdeen university”, which might be a key in another project dataset?

When trying to reconcile data across two different datasets, you may find you need to try to minimise the distance between almost common key columns by creating new columns in each dataset using the above sorts of technique.

Be careful not to create false positive matches though; and also be mindful that not everything will necessarily match up (you may get empty cells when using cell.cross; (to mitigate this, filter rows using a crossed column to find ones where there was no match and see if you can correct them by hand). Even if you don’t completely successful cross data from one project to another, you might manage to automate the crossing of most of the rows, minimising the amount of hand crafted copying you might have to do to tidy up the real odds and ends…

So for example, here’s what I ended up using to create a “Pure key” column in Merge Test C:
fingerprint(replace(replace(replace(toLowercase(value),'the',''),'of',''),'university',''))

And in Merge Test A I create a “Complementary Key” column from the University column using fingerprint(value)

From the Complementary Key column in Merge Test A we call out to Merge Test C: cell.cross("Merge Test C", "Pure key").cells["UCAS ID"].value[0]

Obviously, this approach is far from ideal (and there may be more “correct” and/or efficient ways of doing this!) and the process described above is admittedly rather clunky, but it does start to reveal some of what’s involved in trying to bring data across to one Google Refine project from another using columns that don’t quite match in the original dataset, although they do (nominally) refer to the same thing, and does provide a useful introductory exercise to some of the really quite powerful text processing commands in Google Refine …

First Play With R and R-Studio – F1 Lap Time Box Plots

Last summer, at the European Centre for Journalism round table on data driven journalism, I remember saying something along the lines of “your eyes can often do the stats for you”, the implication being that our perceptual apparatus is good at pattern detection, and can often see things in the data that most of us would miss using the very limited range of statistical tools that we are either aware of, or are comfortable using.

I don’t know how good a statistician you need to be to distinguish between Anscombe’s quartet, but the differences are obvious to the eye:

Anscombe's quartet /via Wikipedia

Another shamistician (h/t @daveyp) heuristic (or maybe it’s a crapistician rule of thumb?!) might go something along the lines of: “if you use the right visualisations, you don’t necessarily need to do any statistics yourself”. In this case, the implication is that if you choose a viualisation technique that embodies or implements a statistical process in some way, the maths is done for you, and you get to see what the statistical tool has uncovered.

Now I know that as someone working in education, I’m probably supposed to uphold the “should learn it properly” principle… But needing to know statistics in order to benefit from the use of statistical tools seems to me to be a massive barrier to entry in the use of this technology (statistics is a technology…) You just need to know how to use the technology appropriately, or at least, not use it “dangerously”…

So to this end (“democratising access to technology”), I thought it was about time I started to play with R, the statistical programming language (and rival to SPSS?) that appears to have a certain amount of traction at the moment given the number of books about to come out around it… R is a command line language, but the recently released R-Studio seems to offer an easier way in, so I thought I’d go with that…

Flicking through A First Course in Statistical Programming with R, a book I bought a few weeks ago in the hope that the osmotic reading effect would give me some idea as to what it’s possible to do with R, I found a command line example showing how to create a simple box plot (box and whiskers plot) that I could understand enough to feel confident I could change…

Having an F1 data set/CSV file to hand (laptimes and fuel adjusted laptimes) from the China 2001 grand prix, I thought I’d see how easy it was to just dive in… And it was 2 minutes easy… (If you want to play along, here’s the data file).

Here’s the command I used:
boxplot(Lap.Time ~ Driver, data=lapTimeFuel)

Remembering a comment in a Making up the Numbers blogpost (Driver Consistency – Bahrain 2010) about the effect on laptime distributions from removing opening, in and out lap times, a quick Google turned up a way of quickly stripping out slow times. (This isn’t as clean as removing the actual opening, in and out lap times – it also removes mistake laps, for example, but I’m just exploring, right? Right?!;-)

lapTime2 <- subset(lapTimeFuel, Lap.Time < 110.1)

I could then plot the distribution in the reduced lapTime2 dataset by changing the original boxplot command to use (data=lapTime2). (Note that as with many interactive editors, using your keyboard’s up arrow displays previously entered commands in the current command line; so you can re-enter a previously entered command by hitting the up arrow a few times, then entering return. You can also edit the current command line, using the left and right arrow keys to move the cursor, and the delete key to delete text.)

Prior programming experience suggests this should also work…

boxplot(Lap.Time ~ Driver, data=subset(lapTimeFuel, Lap.Time < 110))

Something else I tried was to look at the distribution of fuel weight adjusted laptimes (where the time penalty from the weight of the fuel in the car is removed):

boxplot(Fuel.Adjusted.Laptime ~ Driver, data=lapTimeFuel)

Looking at the release notes for the latest version of R-Studio suggests that you can build interactive controls into your plots (a bit like Mathematica supports?). The example provided shows how to change the x-range on a plot:
manipulate(
plot(cars, xlim=c(0,x.max)),
x.max=slider(15,25))

Hmm… can we set the filter value dynamically I wonder?

manipulate(
boxplot(Lap.Time ~ Driver, data=subset(lapTimeFuel, Lap.Time < maxval)),
maxval=slider(100,140))

Seems like it…?:-) We can also combine interactive controls:

manipulate(boxplot(Lap.Time ~ Driver, data=subset(lapTimeFuel, Lap.Time < maxval),outline=outline),maxval=slider(100,140),outline = checkbox(FALSE, "Show outliers"))

Okay – that’s enough for now… I reckon that with a handful of commands on a crib sheet, you can probably get quite a lot of chart plot visualisations done, as well as statistical visualisations, in the R-Studio environment; it also seems easy enough to build in interactive controls that let you play with the data in a visually interactive way…

The trick comes from choosing visual statistics approaches to analyse your data that don’t break any of the assumptions about the data that the particular statistical approach relies on in order for it to be applied in any sensible or meaningful way.

[This blog post is written, in part, as a way for me to try to come up with something to say at the OU Statistics Group’s one day conference on Visualisation and Presentation in Statistics. One idea I wanted to explore was: visualisations are powerful; visualisation techniques may incorporate statistical methods or let you “see” statistical patterns; most people know very little statistics; that shouldnlt stop them being able to use statistics as a technology; so what are we going to do about it? Feedback welcome… Err….?!]

Fragments: Glueing Different Data Sources Together With Google Refine

I’m working on a new pattern using Google Refine as the hub for a data fusion experiment pulling together data from different sources. I’m not sure how it’ll play out in the end, but here are some fragments….

Grab Data into Google Refine as CSV from a URL (Proxied Google Spreadsheet Query via Yahoo Pipes)

Firstly, getting data into Google Refine… I had hoped to be able to pull a subset of data from a Google Spreadsheet into Google Refine by importing CSV data obtained from the spreadsheet via a query generated using my Google Spreadsheet/Guardian datastore explorer (see Using Google Spreadsheets as a Database with the Google Visualisation API Query Language for more on this) but it seems that Refine would rather pull the whole of the spreadsheet in (or at least, the whole of the first sheet (I think?!)).

Instead, I had to tweak create a proxy to run the query via a Yahoo Pipe (Google Spreadsheet as a database proxy pipe), which runs the spreadsheet query, gets the data back as CSV, and then relays it forward as JSON:

Here’s the interface to the pipe – it requires the Google spreadsheet public key id, the sheet id, and the query… The data I’m using is a spreadsheet maintained by the Guardian datastore containing UK university fees data (spreadsheet.

You can get the JSON version of the data out directly, or a proxied version of the CSV, as CSV via the More options menu…

Using the Yahoo Pipes CSV output URL, I can now get a subset of data from a Google Spreadsheet into Google Refine…

Here’s the result – a subset of data as defined by the query:

We can now augment this data with data from another source using Google Refine’s ability to import/fetch data from a URL. In particular, I’m going to use the Yahoo Pipe described above to grab data from a different spreadsheet and pass it back to Google Refine as a JSON data feed. (Google spreadsheets will publish data as JSON, but the format is a bit clunky…)

To test out my query, I’m going to create a test query in my datastore explorer using the Guardian datastore HESA returns (2010) spreadsheet URL (http://spreadsheets1.google.com/spreadsheet/ccc?hl&key=tpxpwtyiYZwCMowl3gNaIKQ#gid=0) which also has a column containing HESA numbers. (Ultimately, I’m going to generate a URL that treats the Guardian datastore spreadsheet as a database that lets me get data back from the row with a particular HESA code column value. By using the HESA number column in Google Refine to provide the key, I can generate a URL for each institution that grabs its HESA data from the Datastore HESA spreadsheet.)

Hit “Preview Table Headings”, then scroll down to try out a query:

Having tested my query, I can now try the parameters out in the Yahoo pipe. (For example, my query is select D,E,H where D=21 and the key is tpxpwtyiYZwCMowl3gNaIKQ; this grabs data from columns D, E and H where the value of D (HESA Code) is 21). Grab the JSON output URL from the pipe, and use this as a template for the URL template in Google Refine. Here’s the JSON output URL I obtained:

http://pipes.yahoo.com/pipes/pipe.run?_id=4562a5ec2631ce242ebd25a0756d6381
&_render=json&key=tpxpwtyiYZwCMowl3gNaIKQ
&q=select+D%2CE%2CH+where+D%3D21

Remember, the HESA code I experiment with was 21, so this is what we want to replace in the URL with the value from the HESA code column in Google Refine…

Here’s how we create the URLs built around/keyed by an appropriate HESA code…

Google Refine does its thing and fetches the data…

Now we process the JSON response to generate some meaningful data columns (for more on how to do this, see Tech Tips: Making Sense of JSON Strings – Follow the Structure).

First say we want to create a new column based on the imported JSON data:

Then parse the JSON to extract the data field required in the new column.

For example, from the HESA data we might extract the Expenditure per student /10:

value.parseJson().value.items[0]["Expenditure per student / 10"]

or the Average Teaching Score (value.parseJson().value.items[0]["Average Teaching Score"]):

And here’s the result:

So to recap:

– we use a Yahoo Pipe to query a Google spreadsheet and get a subset of data from it;
– we take the CSV output from the pipe and use it to create a new Google Refine database;
– we note that the data table in Google Refine has a HESA code column; we also note that the Guardian datastore HESA spreadsheet has a HESA code column;
– we realise we can treat the HESA spreadsheet as a database, and further that we can create a query (prototyped in the datastore explorer) as a URL keyed by HESA code;
– we create a new column based on HESA codes from a generated URL that pulls JSON data from a Yahoo pipe that is querying a Google spreadsheet;
– we parse the JSON to give us a couple of new columns.

And there we have it – a clunky, but workable, route for merging data from two different Google spreadsheets using Google Refine.

Data for journalists: JSON for beginners

Following the post earlier this week on XML and RSS for journalists I wanted to look at another important format for journalists working with data: JSON.

JSON is a data format which has been rising in popularity over the past few years. Quite often it is offered alongside – or instead of – XML by various information services, such as Google Maps, the UK Postcodes API and the Facebook Graph API.

Because of this, in practice JSON is more likely to be provided in response to a specific query (“Give me geographical and political data about this location”) than a general file that you access (“Give me all geographical data about everywhere”).

I’ll describe how you supply that query below. Continue reading

Tech Tips: Making Sense of JSON Strings – Follow the Structure

Reading through the Online Journalism blog post on Getting full addresses for data from an FOI response (using APIs), the following phrase – relating to the composition of some Google Refine code to parse a JSON string from the Google geocoding API – jumped out at me: “This took a bit of trial and error…”

google-refnie-took-a-bit-of-trial-and-error

Why? Two reasons… Firstly, because it demonstrates a “have a go” attitude which you absolutely need to have if you’re going to appropriate technology and turn it to your own purposes. Secondly, because it maybe (or maybe not…) hints at a missed trick or two…

So what trick’s missing?

Here’s an example of the sort of thing you get back from the Google Geocoder:

{ “status”: “OK”, “results”: [ { “types”: [ “postal_code” ], “formatted_address”: “Milton Keynes, Buckinghamshire MK7 6AA, UK”, “address_components”: [ { “long_name”: “MK7 6AA”, “short_name”: “MK7 6AA”, “types”: [ “postal_code” ] }, { “long_name”: “Milton Keynes”, “short_name”: “Milton Keynes”, “types”: [ “locality”, “political” ] }, { “long_name”: “Buckinghamshire”, “short_name”: “Buckinghamshire”, “types”: [ “administrative_area_level_2”, “political” ] }, { “long_name”: “Milton Keynes”, “short_name”: “Milton Keynes”, “types”: [ “administrative_area_level_2”, “political” ] }, { “long_name”: “United Kingdom”, “short_name”: “GB”, “types”: [ “country”, “political” ] }, { “long_name”: “MK7″, “short_name”: “MK7″, “types”: [ “postal_code_prefix”, “postal_code” ] } ], “geometry”: { “location”: { “lat”: 52.0249136, “lng”: -0.7097474 }, “location_type”: “APPROXIMATE”, “viewport”: { “southwest”: { “lat”: 52.0193722, “lng”: -0.7161451 }, “northeast”: { “lat”: 52.0300728, “lng”: -0.6977000 } }, “bounds”: { “southwest”: { “lat”: 52.0193722, “lng”: -0.7161451 }, “northeast”: { “lat”: 52.0300728, “lng”: -0.6977000 } } } } ] }

The data represents a Javascript object (JSON = JavaScript Object Notation) and as such has a standard form, a hierarchical form.

Here’s another way of writing the same object code, only this time laid out in a way that reveals the structure of the object:

{
  "status": "OK",
  "results": [ {
    "types": [ "postal_code" ],
    "formatted_address": "Milton Keynes, Buckinghamshire MK7 6AA, UK",
    "address_components": [ {
      "long_name": "MK7 6AA",
      "short_name": "MK7 6AA",
      "types": [ "postal_code" ]
    }, {
      "long_name": "Milton Keynes",
      "short_name": "Milton Keynes",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "Buckinghamshire",
      "short_name": "Buckinghamshire",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Milton Keynes",
      "short_name": "Milton Keynes",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "United Kingdom",
      "short_name": "GB",
      "types": [ "country", "political" ]
    }, {
      "long_name": "MK7",
      "short_name": "MK7",
      "types": [ "postal_code_prefix", "postal_code" ]
    } ],
    "geometry": {
      "location": {
        "lat": 52.0249136,
        "lng": -0.7097474
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 52.0193722,
          "lng": -0.7161451
        },
        "northeast": {
          "lat": 52.0300728,
          "lng": -0.6977000
        }
      },
      "bounds": {
        "southwest": {
          "lat": 52.0193722,
          "lng": -0.7161451
        },
        "northeast": {
          "lat": 52.0300728,
          "lng": -0.6977000
        }
      }
    }
  } ]
}

Making Sense of the Notation

At its simplest, the structure has the form: {“attribute”:”value”}

If we parse this object into the jsonObject, we can access the value of the attribute as jsonObject.attribute or jsonObject[“attribute”]. The first style of notation is called a dot notation.

We can add more attribute:value pairs into the object by separating them with commas: a={“attr”:”val”,”attr2″:”val2″} and address them (that is, refer to them) uniquely: a.attr, for example, or a[“attr2”].

Try it out for yourself… Copy and past the following into your browser address bar (where the URL goes) and hit return (i.e. “go to” that “location”):

javascript:a={"attr":"val","attr2":"val2"}; alert(a.attr);alert(a["attr2"])

(As an aside, what might you learn from this? Firstly, you can “run” javascript in the browser via the location bar. Secondly, the javascript command alert() pops up an alert box:-)

Note that the value of an attribute might be another object.

obj={ attrWithObjectValue: { “childObjAttr”:”foo” } }

Another thing we can see in the Google geocoder JSON code are square brackets. These define an array (one might also think of it as an ordered list). Items in the list are address numerically. So for example, given:

arr[ “item1”, “item2”, “item3” ]

we can locate “item1″ as arr[0] and “item3″ as arr[2]. (Note: the index count in the square brackets starts at 0.) Try it in the browser… (for example, javascript:list=["apples","bananas","pears"]; alert( list[1] );).

Arrays can contain objects too:

list=[ “item1”, {“innerObjectAttr”:”innerObjVal” } ]

Can you guess how to get to the innerObjVal? Try this in the browser location bar:

javascript: list=[ "item1", { "innerObjectAttr":"innerObjVal" } ]; alert( list[1].innerObjectAttr )

Making Life Easier

Hopefully, you’ll now have a sense that there’s structure in a JSON object, and that that (sic) structure is what we rely on if we want to cut down on the “trial an error” when parsing such things. To make life easier, we can also use “tree widgets” to display the hierarchical JSON object in a way that makes it far easier to see how to construct the dotted path that leads to the data value we want.

A tool I have appropriated for previewing JSON objects is Yahoo Pipes. Rather than necessarily using Pipes to build anything, I simply make use of it as a JSON viewer, loading JSON into the pipe from a URL via the Fetch Data block, and then previewing the result:

Another tool (and one I’ve just discovered) is an Air application called JSON-Pad. You can paste in JSON code, or pull it in from a URL, and then preview it again via a tree widget:

Clicking on one of the results in the tree widget provides a crib to the path…

Summary

Getting to grips with writing addresses into JSON objects helps if you have some idea of the structure of a JSON object. Tree viewers make the structure of an object explicit. By walking down the tree to the part of it you want, and “dotting” together* the nodes/attributes you select as you do so, you can quickly and easily construct the path you need.

* If the JSON attributes have spaces or non-alphanumeric characters in them, use the obj[“attr”] notation rather than the dotted obj.attr notation…

PS Via my feeds today, though something I had bookmarked already, this Data Converter tool may be helpful in going the other way… (Disclaimer: I haven’t tried using it…)

If you know of any other related tools, please feel free to post a link to them in the comments:-)

UK Journalists on Twitter

A post on the Guardian Datablog earlier today took a dataset collected by the Tweetminster folk and graphed the sorts of thing that journalists tweet about ( Journalists on Twitter: how do Britain’s news organisations tweet?).

Tweetminster maintains separate lists of tweeting journalists for several different media groups, so it was easy to grab the names on each list, use the Twitter API to pull down the names of people followed by each person on the list, and then graph the friend connections between folk on the lists. The result shows that the hacks are follow each other quite closely:

UK Media Twitter echochamber (via tweetminster lists)

Nodes are coloured by media group/Tweetminster list, and sized by PageRank, as calculated over the network using the Gephi PageRank statistic.

The force directed layout shows how folk within individual media groups tend to follow each other more intensely than they do people from other groups, but that said, inter-group following is still high. The major players across the media tweeps as a whole seem to be @arusbridger, @r4today, @skynews, @paulwaugh and @BBCLauraK.

I can generate an SVG version of the chart, and post a copy of the raw Gephi GDF data file, if anyone’s interested…

PS if you’re interested in trying out Gephi for yourself, you can download it from gephi.org. One of the easiest ways in is to explore your Facebook network

PPS for details on how the above was put together, here’s a related approach:
Trying to find useful things to do with emerging technologies in open education
Doodlings Around the Data Driven Journalism Round Table Event Hashtag Community
.

For a slightly different view over the UK political Twittersphere, see Sketching the Structure of the UK Political Media Twittersphere. And for the House and Senate in the US: Sketching Connections Between US House and Senate Tweeps