Joe Lamantia.com

In Piv­ot­ing on tags to cre­ate bet­ter nav­i­ga­tion UI Matt McAl­lis­ter offers the idea that we’re see­ing “a new user inter­face evolv­ing out of tag data,” and uses Wikio as an exam­ple. For con­text, he places tag clouds within a con­tin­uüm of the evo­lu­tion of web nav­i­ga­tion, from list views to the new tag-based nav­i­ga­tion emerg­ing now.
It’s an insight­ful post, and it allows me to build on strong ground­work to talk more about why and how tag clouds dif­fer from ear­lier forms of nav­i­ga­tion, and will become [part of] a new user inter­face.
Matt iden­ti­fies five ‘leaps’ in web nav­i­ga­tion inter­faces that I’ll summarize:

1. List view; a list of links
2. Left-hand col­umn; a stan­dard loca­tion for lists of links used to navigate
3. Search boxes and results pages; mak­ing very large lists manageable
4. Tab nav­i­ga­tion; a list of other nav­i­ga­tion lists
5. Tag nav­i­ga­tion; tag clouds

A Les­son in ‘Lis­tory’
As Matt men­tions, all four pre­de­ces­sors to tag based nav­i­ga­tion are really vari­a­tions on the under­ly­ing form of the list. There’s use­ful his­tory in the evo­lu­tion of lists as web nav­i­ga­tion tools. Early lists used for nav­i­ga­tion were sta­tic, cho­sen by a site owner, ordered, and flat: recall the lists of favorite sites that appeared at the bot­tom of so many early per­sonal home pages.
These basic nav­i­ga­tion lists evolved a vari­ety of order­ing schemes, (alpha­bet­i­cal, numeric), began to incor­po­rate hier­ar­chy (shown as sub-menus in nav­i­ga­tion sys­tems, or as indent­ing in the left-column Matt men­tions), and allowed users to change their order­ing, for exam­ple by sort­ing on a vari­ety of fields or columns in search results.
From sta­tic lists whose con­tents do not change rapidly and reflect a sin­gle point of view, the lists employed for web nav­i­ga­tion and search results then became dynamic, per­son­al­ized, and reflec­tive of mul­ti­ple points of view. Ama­zon and other e-commerce des­ti­na­tions offered recently viewed items (yours or oth­ers), things most requested, sets bounded by date (pub­lished last year), sets dri­ven by vary­ing para­me­ters (related arti­cles), and lists deter­mined by the nav­i­ga­tion choices of oth­ers who fol­lowed sim­i­lar paths.)
But they remained fun­da­men­tally lists. They item­ized or enu­mer­ated choices of one kind or another, indi­cated implicit or explicit prece­dence through order­ing or the absence of order­ing, and were designed for lin­ear inter­ac­tion pat­terns: start at the begin­ning (or the end, if you pre­ferred an alter­na­tive per­spec­tive — I still habit­u­ally read mag­a­zines from back to front…) and work your way through.
Tag clouds are dif­fer­ent from lists, often by con­tents and pre­sen­ta­tion, and more impor­tantly by basic assump­tion about the kind of inter­ac­tion they encour­age. On tag-based nav­i­ga­tion Matt says, “This is a new layer that pre­empts the search box in a way. The visual rep­re­sen­ta­tion of it is a tag cloud, but the inter­ac­tion is more like a pivot.” Matt’s men­tion of the inter­ac­tion hits on an impor­tant aspect that’s key to under­stand­ing the dif­fer­ences between clouds and lists: clouds are not lin­ear, and are not designed for lin­ear con­sump­tion in the fash­ion of lists.
I’m not say­ing that no one will read clouds left to right (with Roman alpha­bets), or right to left if they’re in Hebrew, or in any other way. I’m say­ing that tag clouds are not meant for ‘read­ing’ in the same way that lists are. As they’re com­monly visu­al­ized today, clouds sup­port mul­ti­ple entry points using visual dif­fer­en­tia­tors such as color and size.
Start­ing in the mid­dle of a list and wan­der­ing around just increases the amount of visual and cog­ni­tive work involved, since you need to remem­ber where you started to com­plete your sur­vey. Start­ing in the “mid­dle” of a tag cloud — if there is such a loca­tion — with a brightly col­ored and big juicy visual morsel is *exactly* what you’re sup­posed to do. It could save you quite a lot of time and effort, if the cloud is well designed and prop­erly ren­dered.
Kunal Anand cre­ated a visu­al­iza­tion of the inter­sec­tions of his del.icio.us tags that shows the dif­fer­ences between a cloud and a list nicely. This is at heart a pic­ture, and accord­ingly you can start look­ing at it any­where / any­way you pre­fer.
Visu­al­iz­ing My Del.icio.us Tags

We all know what a list looks like…
iTunes Play Lists

What’s In a Name?
Describ­ing a tag cloud as a weighted list (I did until I’d thought about it fur­ther) misses this impor­tant qual­i­ta­tive dif­fer­ence, and reflects our early stages of under­stand­ing of tag clouds. The term “weighted list” is a list-centered view of tag clouds that comes from the pre­ced­ing frame of ref­er­ence. It’s akin to describ­ing a com­puter as an “arith­metic engine”, or the print­ing press as “mov­able type”.
[Aside: The label for tag clouds will prob­a­bly change, as we develop con­cepts and lan­guage to frame new the user expe­ri­ences and infor­ma­tion envi­ron­ments that include clouds. For exam­ple, the lan­guage Matt uses — the word ‘pivot’ when he talks about the expe­ri­ence of nav­i­gat­ing via the tag cloud in Wikio, not the word ‘fol­low’ which is a default for describ­ing nav­i­ga­tion — in the post­ing and his screen­cast reflects a pos­si­ble shift in fram­ing.]
A Cam­era Obscura For the Seman­tic Land­scape
I’ve come to think of a tag cloud as some­thing like the image pro­duced by a cam­era obscura.
Cam­era Obscura

Where the cam­era obscura ren­ders a real-world land­scape, a tag cloud shows a seman­tic land­scape like those cre­ated by Amber Frid-Jimenez at MIT.
Seman­tic Land­scape

Seman­tic Land­scape

Like a cam­era obscura image, a tag cloud is a fil­tered visu­al­iza­tion of a mul­ti­di­men­sional world. Unlike a cam­era obscura image, a tag cloud allows move­ment within the land­scape. And unlike a list, tag clouds can and do show rela­tion­ships more com­plex than one-dimensional lin­ear­ity (expe­ri­enced as prece­dence). This abil­ity to show more than one dimen­sion allows clouds to reflect the struc­ture of the envi­ron­ment they visu­al­ize, as well as the con­tents of that envi­ron­ment. This frees tag clouds from the lim­i­ta­tion of sim­ply item­iz­ing or enu­mer­at­ing the con­tents of a set, which is the fun­da­men­tal achieve­ment of a list.
Ear­lier, I shared some obser­va­tions on the struc­tural evo­lu­tion — from sta­tic and flat to hier­ar­chi­cal and dynamic — of the lists used as web nav­i­ga­tion mech­a­nisms. As I’ve ven­tured else­where, we may see a sim­i­lar evo­lu­tion in tag clouds.
It is already clear that we’re wit­ness­ing evo­lu­tion in the pre­sen­ta­tion of tag clouds in step with their greater visu­al­izatin capa­bil­i­ties. Clouds now rely on an expand­ing vari­ety of visual cues to show an increas­ingly detailed view of the under­ly­ing seman­tic land­scape: prox­im­ity, depth, bright­ness, inten­sity, color of item, color of field around item. I expect clouds will develop other cues to help depict the many con­nec­tions (per­ma­nent or tem­po­rary) link­ing the labels in a tag cloud. It’s pos­si­ble that tag clouds will offer a user expe­ri­ence sim­i­lar to some of the ontol­ogy man­age­ment tools avail­able now.
Is this “a new user inter­face”? That depends on how you define new. In Shap­ing Things, author and futur­ist Bruce Ster­ling sug­gests, “the future com­posts the past” — mean­ing that new ele­ments are sub­sumed into the accu­mu­la­tion of lay­ers past and present. In the con­text of nav­i­ga­tion sys­tems and tag clouds, that implies that we’ll see mix­tures of lists from the four pre­vi­ous stages of nav­i­ga­tion inter­face, and clouds from the lat­est leap; a fusion of old and new.
Exam­ples of this com­post­ing abound, from 30daytags.com to Wikio that Matt McAl­lis­ter exam­ined.
30DayTags.com Tag Clouds

Wikio Tag Cloud

As lists encour­aged lin­ear inter­ac­tions as a result of their struc­ture, it’s pos­si­ble that new user inter­faces rely­ing on tag clouds will encour­age dif­fer­ent kinds of seek­ing or find­ing behav­iors within infor­ma­tion expe­ri­ences. In “The endan­gered joy of serendip­ity” William McK­een bemoans the decrease of serendip­ity as a result of pre­cisely directed and tar­geted media, search­ing, and inter­ac­tions. Tag clouds — by offer­ing many con­nec­tions and mul­ti­ple entry paths simul­ta­ne­ously — may help reju­ve­nate serendip­ity in dan­ger in a world of closely focused lists.