For those of you who aren’t familiar with cricket a bowler’s average is calculated by dividing the number of runs scored against the bowler by the number of wickets taken. If a bowler has the amazingly good average of 20 it means that they take a wicket every 20 runs.

One problem with this metric is that the quality of the batsmen dismissed will vary. Some bowlers will have tidied up the tail end batsmen more often. Others might be adept at getting out the upper order. How do we distinguish between these two? The solution is to deduct the averages of the batsmen dismissed from the average before dividing by the overs bowled. I call this measure “Bowler’s contribution”

Bowler’s contribution = (bowlers average – average of batsmen’s averages) / overs bowled

The outcome is that you have a measurement which takes into consideration all relevant factors:

• number of wickets taken
• number of runs conceeded
• quality of batsmen dismissed
• number of overs bowled

So, lets take four bowlers:

Using the traditional method the best bowlers here would be Alfie and Bertie. However, the “contribution” method scored Alfie and Charlie the best because they are dismissing batsmen of a higher calibre.

This new method does have practical problems associated with it because it requires that the statistician know all of the batsmen’s averages for each innings they play. This is not the kind of statistic you will necessarily find in a book but it shouldn’t be too difficult to calculate if you have a comprehensive historical record.

So there you have it. It would be very interesting to see how bowlers would line up using this method. I reckon it would uncover a few unappreciated gems. Something more for the commentators to talk about. Cricket fans… what do you think? Let me know in the comments who the best all time bowlers would be on this new criteria.

In the back of my mind though I had been wanting to complete a longer walk which would take up the entire night – from sunset to sunrise. I was aiming to undertake such a walk during the winter solstice but I had a cold back then and so was unable to attempt it. Anyway, it’s still pretty close to the solstice so there is still a lot of night to walk through… 14 hours of it, 4km/h… that’s around 56km. I calculated that a Penrith to Bondi walk had a nice ring to it. It came in at around 60km according to Google maps. If I timed it right I could get to Bondi at sunrise. Also, if I got too knackered and the call of bed got too strong I could always wimp out around Camperdown, making the walk 52 km.

OK. That all sounded good and so I decided to give it a go. Rang Mike and Steve up but wisely they were suffering colds or had better things to do. Smart move.

There was trackwork on of course. Luckily there was a direct bus out to Penrith which was pretty quick. I got the arround 4.45 and made it to the river just on sunset. Right on. All up it went pretty well. My feet held up OK and the pace was pretty good. Managed to solve a few technical problems which I was ruminating on…

It wasn’t without unpleasantness though. I really had underestimated the desolation of the Great Western Highway. In my mind I had sort of imagined a continuation of Paramatta Road but boy I was wrong. What was I thinking? That road is by no means pedestrian friendly. For a lot of the way I was creeping along the edge of the roadside barrier with cars whizzing by. At its worst it was through knee high grass. Sometimes the median strip was best. There were a few times where I really did consider it all a bit ill conceived. I got that kind of creepy feeling of there only being one way out of it and that was forward. You know – when you have to rely on yourself alone. I think Steve Waugh calls it a “comfort zone” In a funny kind of way that is why I do these walks. Eventually some lights appeared on the horizon and Wentworthville emerged. Footpaths. Street lights. Service stations. Street signs. The very occasional person. And a bit of hope. Oh joy.

I must have been pretty scared because I clocked up that 30km in about 5 and a bit hours – way faster than my usual 5km per hour. The next 20 km was pretty uneventful. It was great to be back in civilisation. I’ve now seen every car sales yard in Sydney. Memos kebab shop really makes a tasty kebab BTW Heh. Anyway, for the last 10 clicks or so the blisters were getting a bit bad and so I did decide to call it a night at Camperdown. Bondi would have to wait for another day. 52km all up in a little less than 12 hours. I won’t be doing that walk again anytime soon. Glad to have done it though.

Out of the box WordPress comes with a fairly small set of hard-baked object types which don’t necessarily map particularly well to the semantic web:

• pages
• posts
• comments
• links
• users
• tags, categories and link categories.

The options for relating things have been pretty limited:

• posts can be related to tags and categories
• links can be related to link categories
• users and posts can have metadata but no out of the box display for this.

Taxonomies

As of WordPress 2.3 the database schema changed to introduce “taxonomies”. This involved a rejigging of the way categories and tags were stored and related. This allowed for the creation of custom realtionships to be made. ie. it is possible to create custom relationship types such as “is a”, “studied”, “likes”, etc. This allows for much richer metadata to be produced. Out of the box taxonomies are not available to WordPress users but plugin developers are able to use the new data structures to come up with something better than what is available with tags and categories.

Check out these two posts explaining the changes

• Tip #5 : Taxonomy in WordPress 2.3
• WordPress 2.3 Taxonomy Schema

This all looks promising. However, I was a bit disappointed with the way things had been implemented in the backend. To me it seems that some less than optimal decision were made.

The thoughts that follow are a result of looking at the DB schema only. I have not peered into the code or am aware of the background for making the decisions that were made.

The old WordPress had the following tables:

• categories
• post2cat
• link2cat

The new WordPress has factored these replaced them with three new tables:

wp_terms
term_id
name
slug

wp_term_taxonomy
term_taxonomy_id
term_id
taxonomy
description
parent
count

wp_term_relationships
object_id
term_taxonomy_id

Please read WordPress 2.3 Taxonomy Schema for a better understanding of how the above three tables work together. I will make a few points at this stage.

• the terms table handles names and slugs for category, link_category and post_tag. The slug provides the unique index. This design seems very strange to me as we have three namespaces (category, link_category and post_tag) which are being constrained by a single slug namespace. It therefore seems impossible to have the same slug represent different concepts (or names) across namespaces. eg /category/max (the “max” size) and /tag/Max (the “Max” person). The schema just smooshes the namespaces together, limiting expressiveness. This might be acceptable if there were only one namespace but there isn’t. This makes me a bit concerned about renaming things. If one term is forming double duty for a tag and a category, then the rename of one will knock onto the other.
• naming duties are split between wp_terms and wp_term_taxanomy. Why does wp_terms get name and slug, and
  wp_term_taxonomy get description? Weird. I can’t see the benefit of the wp_terms table. One argument for it might be that wp_terms is there to handle duplication of names and to save space. I don’t buy this. Names and slugs are short, clashes are relatively rare and we have the namespace slug problem above. I can’t see the point of wp_terms. Further, any query would need to join across to wp_terms to get the name – a pointless exercise.
• according to the documentation the object_id property type in wp_term_relationships can take a link_id or a post_id. What? This breaks the relational model. We don’t know what the ID represents in this table. Is it a link or a post? The only way I can see this working is to join across to wp_taxonomy and restrict on the taxonomy value! ie. you need to do a join to restrict the object ID. I haven’t checked the code so I can’t be sure. I must be missing something here but that is the only way I can see it working. This must lead to less than efficient querying on big datasets.

So that’s me being a bit critical of the design of taxonomies as it stands technically. However, I have bigger problems with what can be achieved sematically with it. The main limitation lies with the content of the wp_term_relationships table. You are limited into what can go into object_id (links and posts) and what can go into term_taxonomy_id (category, link_category, tag, custom). There is a divide between the resources would and the subjects world. This means that it is impossible to:

• relate posts with posts, links, users, comments or pages
• relate links with posts, links, users, comments or pages
• relate users, commentsor pages with anything

This really is a massive lost opportunity. Why the limitation?

The main problem for me is not being able to relate posts with posts. It is very common to want to encode a “see also” or a “is friends with” or “works for”. If you have this content in your WordPress as a post rather than a tag/category/custom then you are out of luck. For users who are using WordPress as a CMS with most of the content is posts (in order to get the benefits of tags and categories) this is a frustrating situation.

Another obvious loss is the inability for tags and categories to apply to pages. This kind of functionality is often bolted on by plugins. It would be nice if it could be supported natively.

Suggested alternative

OK. What would be a better design? If I were to take a stab at it I would solve it in two tables, rather than three.

mw_term
term_id
subtype (“tag”|”category”|”custom”|”predicate”)
title
slug
description
parent
unique index: subtype + slug

1 = _category (subtype:predicate)
2 = _link_category (subtype:predicate)
3 = _post_tag (subtype:predicate)

This design solves the term problem by making a single mw_term table which handles all of the naming: title, slug and description. It also handles the namespacing problem because uniqueness is solved with slug + subtype index. The subtype handles the old “taxonomy” values but also includes another: predicate.

Predicates join subjects and objects. They could have their own table for naming but why double up? Lets just put them into the mw_term table. You can see that the first three rows in mw_term are for the category, link_category and post_tag terms.

mw_triple
subject_type (post, link, term, user, comment, page)
subject_id
predictate_id
object_type (post, link, term, user, comment, page)
object_id

And here we have a standard relationship table which relates subjects with objects. This is very much like an RDF triple. You can see that this allows us to relate anything to anything resulting in the most freedom of expression. It is now possible to do some very helpful stuff without plugins:

• relate posts to posts
• relate pages to categories and tags
• relate tags/custom to tags/custom

If we wanted to represent “joe (post_id=1) worksfor acme (post_id=2)” we would have the following:

mw_term.term_id = x
mw_term.subtype = custom
mw_term.title = “Works for”
mw_term.slug = “works-for”

mw_triple.subject_type = “post”
mw_triple.Subject_id = 1
mw_triple.predictate_id = x
mw_triple.object_type = “post”
mw_triple.Object_id = 2

This is simple and straight forward.

What can be done in the current framework?

The most obvious thing is not to worry and just work with post-custom taxonomies. These are quite powerful and should get you a long way. This approach should gain a quick takeup once the taxonomy plugins become more widely deployed and used. For example, the Simple Taxonomies plugin is very simple to use and quite intuitive. If only I could get the target links to work

But what is we want to do more within the wp_term_taxonomy paradigm. What can we do? It would be possible to hack some “proxy” term_taxonomies to make statements about posts. This allows us to make statements about a post as an object (in the triples sense of the word).

We will reuse the “joe worksfor acme” example above. The posts get some auto created terms which we can use to relate them. The hack here is to have a shadow term for each post.

wp_terms.term_id = x
wp_terms.name = “mw.post_id.1″
wp_terms.slug = “mw.post_id.1″

wp_terms.term_id = y
wp_terms.name = “mw.post_id.2″
wp_terms.slug = “mw.post_id.2″

wp_term_taxonomy.wp_term_taxonomy_id = t
wp_term_taxonomy.taxonomy = “Works for”
wp_term_taxonomy.term_id = y

wp_term_relationships.object_id = 1
wp_term_relationships.term_taxonomy_id = t

We have just expressed “joe worksfor acme”. This is obviously a lot more complex than the example because we are forcing it to do something it doesn’t want to do.

This is problematic mainly because of duplication of data in wp_terms, making data integrity harder. If “joe” is deleted we will need to delete wp_terms.1. The row wp_term_taxonomy.t might also need to be deleted since it is an orphan. It also doesn’t solve the case where we want to relate tags with tags or custom with custom. So this is a sub-optimal solution.

Conclusion

The best way to look at taxonomies is to consider them as tags on steroids. To be honest this will solve a lot of problems and I am looking forward to using them to improve my tag structure. This will get me most of the way there.

I did have the dream of being able to import RDF and dump it into the two metadata centers in WordPress: Custom Fields for literals and Taxonomy for relationships. Or failing that, at the very least I wanted an easy way to relate my posts. However, it now appears that the taxonomy structure is a halfway house which isn’t capable of supporting structures as flexible as those found in RDF. It also seems to fall short for simpler things as well.  If you wanted to go down this path then the best bet seems to support a data structure outside of the WordPress tables which is a shame. How easy would it be to plug in an open source Topic Maps or RDF engine to support these relationships?

The Sydney Institute publishes the Sydney Papers, a quarterly publication of the various speeches given at weekly events. The Sydney Institute required a CMS which would allow them to maintain a subscription list where paying members have access to protected content. This was implemented as a WordPress site with a subscription manager.

Requirement: Content Management, Publishing, Subscription
Technology: WordPress, PayPal, Theme customisation

The other day I took a couple of friends visiting from the UK for a trip up to the Northern Beaches of Sydney. We dropped by Cottage Point for lunch and then made our way up to Palm Beach and Pitwatter for a bit of a dip and an ice cream. On the way back to Sydney I noticed the roadsign which was to be the genesis for the Night Walkers group: Sydney 40km.

That got me thinking. 40km is nearly a marathon and I had always wanted to complete a marathon. I decided then and there to give my friend Mike a ring to see if he would be interested in walking a marathon in the cool of night. I knew that Mike would be up for it as he doesn’t like to be beaten by a challenge.

And so on the 30th Jan 2009 we made the journey from Palm Beach to the GPO on foot. It took us nine and a half hours and it is fair to say that we were knackered by the end of it. The chaffing was extreme, the blisters were pretty bad too and we were well and truely ready for the comforts of our beds waiting at home.

During the evening we discussed many things including what the next walk would be of course. We flirted with a Wollongong to Sydney walk but soon realised that 40km was challenge enough. We put such discussions on ice until we finished. Anyway… from that initial walk the Night Walkers facebook group was created. We have since completed a few more walks and are looking for new members to take up the challenge. If you feel like doing something a little crazy please join us.

New Leaf Publishing is a small publishing house providing editorial and production services. It required a website outlining its services and contact information.

Requirement: Brouchure-ware
Technology: HTML, CSS

If you have any photographic techniques then I would love to hear about them in the comments.

Shoot relection in water
Get the focus right. Don’t just mirror images – make the single subject the focus.

Shoot through water
Make sure there’s no reflection.
http://www.flickr.com/photos/djs1021/29143860/

Self referential
Take a photo, print, return to the scene and take a photo of the photo. Interesting but a bit cheap unless relevant.
http://www.flickr.com/photos/raul/41476707/
http://www.flickr.com/photos/95111447@N00/40238228/

BW for portraits
Grain and starkness add gravitas to subjects
http://www.flickr.com/photos/eddielaw/49919568/
http://www.flickr.com/photos/stillpicture/39463802/
http://www.flickr.com/photos/babsi/42389067/
http://www.flickr.com/photos/cariephoto/show/

Night shots enhanced by lingering sunset
Adds colour and drama to the image
http://www.flickr.com/photos/wilfjames/822205/

Close ups of chaos makes viewer doubletake
The viewer spends longer processing the image leading to more rewarding consumption
http://www.flickr.com/photos/yeahboone/28365913/
http://www.flickr.com/photos/wolffman17/16998094/

Fame and action are enough
Good subjects always work. See paparazi and sports photographers. The subject matter speaks for itself.
http://www.flickr.com/photos/froodmat/51128168/
http://www.flickr.com/photos/whatevernevermind/22981532/
http://www.flickr.com/photos/pixelydixel/6321340/

A new perspective
Put the lense where the eye can’t go: high, low, big, small.
http://www.flickr.com/photos/lenny_meriel/20297074/
http://www.flickr.com/photos/vision_aerie/3245770/
http://www.flickr.com/photos/samuelyung/37945030/

Camera is faster than the eye
It can reveal things we never see with the naked eye. Run of the mill, point and shoot, photos are generally too slow.
http://www.flickr.com/photos/borghetti/6596202/

Photographers photo
Photographers have their own tricks whci add a sense of unreality to an image and takes it out of the everyday: play with light, backlit, noir, infra red.
http://www.flickr.com/photosrtofgold/32012683/
http://www.flickr.com/photos/theorem/23719776/
http://www.flickr.com/photos/bhikku/17602694/
http://www.flickr.com/photosckley/2942132/

Beauty in abstract
Abstract shapes sparate the image from photography and reach to other ideas. Also good for contrasting the natural and mechanical.
http://www.flickr.com/photos/bryan/25652552/
http://www.flickr.com/photos/clearlyambiguous/19985476/

Photo as canvas
Crops on street art elevate the art to a canvas once the grime of the street is removed.
http://www.flickr.com/photos/dispositive/23114600/

Juxtapose for comic effect
Jokes are unexpected truth, so too with photos. Works well for portraits. Gets you another look in at the subject.
http://www.flickr.com/photos/henk/796710/
http://www.flickr.com/photos/janv/13816599/
http://www.flickr.com/photos/betina/13993717/

Contrast for interest
Contrating subject matter makes us think.
http://www.flickr.com/photos/whileseated/50636340/
http://www.flickr.com/photos/twmlabs/41482884/

Focus draws attention to an idea
A non descript photo gains strength by telling a story by emphasising certain elements through focus/blurring.

Colour stands out
Look for blocks, gradations and contrasts.
http://www.flickr.com/photos/mylakent/63475757/
http://www.flickr.com/photos/marct/32766382/
http://www.flickr.com/photos/34379736@N00/64086472/
http://www.flickr.com/photos/chun/9887123/

Form can be interesting too
Probably doesn’t have as much punch as colour.
http://www.flickr.com/photos/k/4505471/
http://www.flickr.com/photos/51035555243@N01/34337425/
http://www.flickr.com/photos/esthet/3753156/
http://www.flickr.com/photos/cariephoto/2433627/

Texture is cool as well
Even more subtlehttp://www.flickr.com/photos/special/3912163/
http://www.flickr.com/photos/pictobox/4747479/
http://www.flickr.com/photos/bingolittle/4302278/

Less is more
Photos can trigger a creative process like a book. It doesn’t all have to be spelt out.
http://www.flickr.com/photos/emikohime/62333544/
http://www.flickr.com/photos/velvethellvis/41596903/
http://www.flickr.com/photos/john/10881278/in/pool-moms/

Be brave to get the subjects
A lot of images are the same. You need to become at one with your subject
http://www.flickr.com/photos/cdierdorff/53940727/

Strangeness is evocative
Staged photos don’t strike me head on but do evoke strange mixed feelings.
http://www.flickr.com/photos/furnari/8481521/

The passing of time
Images capture a fraction of a second but the can capture so much more: exposure, repetition, blurring, sequence.
http://www.flickr.com/photos/oceanbornstudios/36360575/
http://www.flickr.com/photos/jonlucas/17302350/
http://www.flickr.com/photos/reality/3764433/
http://www.flickr.com/photos/patisfaction/1864688/

Window to another world
Viewing a photo is voyeristic. We gain insights into another’s world – a stolen moment. These are the trickiest photos to get and I feel quite guilty about taking them. The viewer avoids most of this guilt as they are reduced to consumer rather than exploiter.
http://www.flickr.com/photos/elix/160596/

Sex sells
Sensual images will stir emotions. Even the suggestion of sex is enough for arousal.
http://www.flickr.com/photos/mivella/15150349/
http://www.flickr.com/photos/43472158@N00/3320688/

Push the limits, strip away the unnecessary
Draw attention the the essential aspects of an image: high contrast. over exposed.
http://www.flickr.com/photos/hkvam/1177681/

The eyes have it
Beauty is in the eye of the beheld.
http://www.flickr.com/photos/twmlabs/41482884/
http://www.flickr.com/photos/noqontrol/11757131/

Shooting to the light increases contrast
Usually you want to avoid it because of loss of detail in forground images, however, striking silohettes can be formed.
http://www.flickr.com/photos/ellishall/52103259/

Maybe this kind of info could be provided on a website. eg. Electricity companies compared, the best water tanks, qualified installers, etc. You can still get the kickbacks but it is free for users.

Idea

This way of thinking can be possibly rectified by placing the person at some time in the future and asking them to image how they would feel at that point in time and then ask them to reconsider the opportunity cost. There is a chance that they will change their decison based on this hindsight.

Example 1: Talented executive decides to forgo leisure time (friends, family, lovers, travel, fitness) for 15 years (25 -40) and accepts high wage. This may seem logical. Now ask them to put themselves in the 40 yo shoes and to consider if the loss of quality of life was worth the $x they have accumulated.

Example 2: Couple close to retirement has a reasonable amount saved and decide to work for another 5 years (63 – 68) to accrue more with the fear that they may hit hard times. Now ask them to put themselves in the shoes of the 68 year old. Maybe there are only a couple of productive years left in their lives. What value would then be put in the previous 5 productive years. Propbably a lot more than what was accrued. ie. The relative value of the enjoyment of the previous 5 years will be valued much higher.