What Is Usability in the Context of the Digital Library and How Can It Be Measured?

By Judy Jeng

Jeng has helped to systematize and codify concrete measures of usability and to survey the state of the art. Her 2004 student paper (the subject of this blog) won the LITA/Endeavor Student Writing Award. LITA is a division of the American Library Association (ALA).

Her model, in outline format, comprises the following.

Usability

1. Related Dimensions

1.1. Effectiveness

1.2. Efficiency

1.3. Satisfaction

1.3.1. Ease of Use

1.3.2. Organization of Information

1.3.3. Labeling

1.3.4. Visual Appearance

1.3.5. Content

1.3.6. Error Correction

2. Learnability

Effectiveness, efficiency, and satisfaction are correlated measures. That is, if a digital library is effective and efficient, one may expect users to be satisfied. Satisfaction relates to six key attributes of the site: is it easy to use, is the information well-organized, are there adequate signposts, is it pleasing to gaze upon, does it have relevant content, and can one recover from an error?

A second important dimension is learnability: are the navigation and finding schema easily internalized by the user?

To gauge usability, Jeng describes the following instruments:

· a pretest questionnaire to collect important demographics and user profiles,

· a list of tasks (various items to find or do),

· post activity interviews,

· think-aloud exercises where the user verbalizes his actions, and

· a post-test questionnaire.

She gives examples of some of these in an appendix along with an extensive bibliography.

I think Jeng’s article and her work are what good library science (and library science writing) is all about. You can find her Ph.D thesis by typing Judy Jeng in the search box located here.

Learnability's Unwritten Problem

The big problem with learnability is that most of the articles are written in English. Don’t get me wrong, English is a wonderful language, easy to conjugate, rich in vocabulary. The only (and easily remediable) problem is the spelling (parody). Let’s face it. English spelling is not user friendly. Why should gauze and gauge or come and home have completely different vowel sounds? We should have learned our lesson. The Brits invented cricket and cribbage, two of the most convoluted games known to man. And don’t forget golf (warning: vulgarity). Their cars leak oil. They invented one of the most inconsistent systems of units (such as BTU, pound, mile, etc.) and then partially abandoned it in favor of the metric system. (Here in the U.S., we’re still stuck with them.)

So lets change our spelling like most other sensible countries and use a completely phonetic coding for words.

Do you think our arcane system of spelling is important? In fact, even when English spelling is mucked up beyond all recognition, native English speakers can still read it, as this site reports:

I cdnuolt blveiee that I cluod uesdnatnrd what I was rdanieg. The phaonmneal pweor of the human mind aoccdrnig to a rscheearch taem at Cmabrigde Uinervtisy: it deosn’t mttaer in what order the ltteers in a word are, the only iprmoatnt thing is that the frist and lsat ltter be in the rghit pclae.

If you would like to see what simplified English looks like, Fox news has written a story about simplified spelling using simplified spelling.