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Tag Clouds: Usability and Math


For determining font sizes, I encountered four techniques (Listing Four). You can see that both absolute (url1) and relative (url2) font sizes are used. You can also translate the weights to CSS class names (url3) or to multiple instances of sizing tags (url4). Undoubtedly, you will think of more alternatives that you would want to support with your code.

I don't address here how you create UI controls or bind HTML tags to data. I assume you can take the ideas from my examples and turn them into working code. Just remember that front-end developers are at least as stubborn as other software engineers. If you decide to create your own UI control, try to facilitate your front-end colleagues by making your HTML generator compatible with several of the techniques mentioned. This also applies to the context in which hyperlinks are placed. Some solutions use HTML for enumerating the text tags; others use spaces to separate them from each other. A UI designer might want other properties of the hyperlinks (such as the intensity of the color) to vary with the weight of the tags. A good UI control will not stand in the way of any creative ideas!

One last bit of advice: Consider that any spaces in tags (like in names of authors) can be replaced by  ; while rendering the HTML. This saves front-end developers the effort of taking measures against undesirable wrapping of the tags.

Dim url1 As String = "<a href='{0}' style='font-size:{1}px;'>{2}</a>"
Dim url2 As String = "<a href='{0}' style='font-size:{1}em;'>{2}</a>"
Dim url3 As String = "<a href='{0}' class='class{1}'>{2}</a>"
Dim url4 As String = "<em>...<em><a href='{0}'>{2}</a></em>...</em>"
Listing Four


To sum up, there are different types of data that can serve as data sources for tag clouds and you can apply different algorithms to distribute font sizes more evenly among tag clouds. Using this information, you can build a generic solution in your own favorite environment that is applicable in many different situations. Hopefully, I will encounter some of your results the next time I am searching for good solutions.

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<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<u> Defines underlined text

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