tial documents (Figure 5). In such cases it might be more logical to refer to the technique as a “word cloud” since it shows word frequency in a text passage instead of tags on a site. (In a sense this is returning to the roots of Milgram’s and Coupland’s diagrams.)

Adding steam to the analytical power of tag clouds, a few sites have created alternative versions of the technique. Our own IBM Research site Many Eyes, which lets users upload and visualize data in a variety of ways, features two flavors of tag clouds: the traditional one-word and an unconventional two-word view. The two-word cloud shows the most frequent two-word phrases in a body of text (disregarding stop words). This simple mechanism gives viewers a much different perspective on the text being visualized, getting closer to some of the themes in the content. For example, the one-word and two-word clouds of a political speech uploaded to Many Eyes give viewers a dramatically distinct understanding of the material (see Figures 6a and 6b).

F F igure5:Atime-basedtagcloud.

 Figure 4: U.S. presidential speeches over time, created with Tagline Generator.

 

000 abraham achievement afford age ago america american americans arrived back begin bills bring bringing broken building call called campaign care challenges chance change changed child children citizenship city civil college common communities congress costs country creation crisis crucial cynics death decency decisions disillusionment distracted divided dreams economy election else’s end energy essential ethanol ethics executives expect face fail failure fair faith families finally forever founders free future generation give government grand happen happened hard health heard heart home honor hope hopes ill immigrants instilling intelligence interests iraq job joined journey kids late law lawyer lay-people lead learned learning life lincoln listen lives lobbyists long love made make march meaning men military millions money moved nation neighborhoods north offered oil opportunity page pass passed pay paycheck peace people plans play political politics poverty power president priorities problems production promises proud providing race rebuilding reform reminded rest rights role running safe schools senator serve set settle sharing single skepticism south special spent springfield stand start stopped struggling system table teachers tells terrorists things time times today told tough travel treatment trivial troops turn turned tyranny understand uniquely veterans washington ways west who’ve women words work working world write year years young

An Information-visualization
Technique

From a traditional information-design perspective, the rapid adoption of tag clouds is surprising because the method has glaring theoretical problems. Long words get undue emphasis over short ones, it is cumbersome to find any single word, and font sizes can be difficult to compare. Alphabetical ordering means that sets of related words are scattered: “East” is close to “Easter” but far from “west.”

Recent empirical work sup-

 Figure 6A: Simple, one-word tag cloud of a speech given by Barack Obama in 2007. Created on Many Eyes. Figure 6A: Simple, one-word tag cloud of a speech given by Barack Obama in 2007. Created on Many Eyes.

$13,000 2008 letting abraham lincoln accept responsibility active participation afford child alternative fuels america converge american lives american people americans feel anxiety americans awakened electorate big problems boy’s heart bring hope broadband lines capital city capping greenhouse captives free care costs care crisis cheap political cherished rights chicago’s poorest child care child turns christian faith chronic avoidance chronically ill citizenship restoring civil rights climate change cold today combat troops common dreams common hopes common purpose community organizer competitive economy constitutional law control costs country offering country safe country’s middle-class crucial role deadliest weapons death penalty death toll decades ago digital age distant executives divided north else’s civil else’s fault ends poverty equality depend essential decency ethics reform ethics reforms families struggling family connections finally frees finally tackles find peace freedom long frees america fuel-efficient cars future generations future schools gangly self-made gay people generations proud give health global warming grand speeches grand sum greenhouse gases _hh_eap_ape_ln_thdivi_cde_ad _rha _erd choices hard work hard-earned benefits _{hard-working americans harness homegrown health insurance helped free} high standards homegrown alternative homeland security hopeful america house divided impossible odds intelligence capabilities interests move interests who’ve iraq mounts job creation job sight job training justice roll katrina happened king’s call lasting friendships law school lawyer tells life continued lifted millions lincoln understood living wage longer divided lost loved made lasting make college make hard make similar makes future making grand mighty stream mistake today mounting debts nation’s workers north south odds people offering ten-point opened railroads to realize parties make passed ethics patriots brought penalty system people back people faced people reaching people turn perfect union plant closings political disagreement political points poorest neighborhoods powerful idea problems people real failures region faith replace diplomacy republican senator rights lawyer rising health rural towns safe place scientific research scoring cheap self-made springfield senator dick september day set high set priorities sigh unseen similar promises simple powerful single simple skewed priorities small part sound policies south east south slave special interests springfield lawyer stagnant wages start bringing steel mill stronger military struggling paycheck sweeping ethics tall gangly taught constitutional tax system teachers businessmen ten-point plans thousand miles time learning tough decisions tough talk tragic mistake troops home ultimate victory uniquely qualified united states universal health unseen motivated unyielding faith voices calling welcomed immigrants who’ve traveled who’ve turned working consensus working families world’s deadliest years candidates young lives

 Figure 6B: Two-word tag cloud of the same Barack Obama speech. This version reveals three main themes in the text: “health care,” “special interests,” and sending the “troops home.” Created on Many Eyes.

 

ports these theoretical concerns. In one experiment subjects shown tag clouds performed worse in word recognition and overall sense making compared with people looking

at simple vertical lists of words in alphabetical order [ 5]. The alphabetical ordering in tag clouds is an important organizing principle because it provides the only way to visually