Usability 101: Memorability

Hav­ing cov­ered learn­abil­ity and effi­ciency as the first two ele­ments of usabil­ity, it is now time to turn to memorability.

What is memorability?

The con­cept of mem­o­ra­bil­ity, within the usabil­ity con­text, is that a user can leave a pro­gram and, when he or she returns to it, remem­ber how to do things in it. How many times have we all gone through a train­ing exer­cise with some­one who knew the sys­tem only to come back to it and be com­pletely con­fused? This is the issue that mem­o­ra­bil­ity tries to address.

Why is mem­o­ra­bil­ity important?

Mem­o­ra­bil­ity is impor­tant largely because users may not be using your appli­ca­tion all the time. In some cases, they might get some train­ing on it, then go off on vaca­tion, then come back and be too swamped with other things to use your piece of soft­ware. There are a vari­ety of rea­sons for which a user may not be using a piece of soft­ware for an extended period of time. When they come back to it, though, you need to make sure that they remem­ber how to use it. In some ways, mem­o­ra­bil­ity can be tied to learn­abil­ity in that it works in the dark recesses of our brains, with cues remind­ing a user how to use a par­tic­u­lar func­tion. Most users will prob­a­bly not be inter­ested in spend­ing a lot of time learn­ing the sys­tem unless they get more out of it. As a result, you need to get the basic stuff to be intuitive.

This is a chal­lenge unto itself as intu­itive behav­ior is not some­thing that is easy to fig­ure out. For exam­ple, if you are a Unix geek, open­ing up a shell win­dow and doing a lot of things at the com­mand prompt seems intu­itive. If you are some­one who is still new to com­put­ers, it is complicated.

As a result, you will find that some of the mem­o­rable things are usu­ally due to one or two factors:

• An action from the user had a reac­tion that the user did not nec­es­sar­ily expect. If that reac­tion left the user with a good feel­ing, he or she will remem­ber it. The oppo­site is true too. This is sim­i­lar to putting one’s hand into a fire: you may do it a first time and get burned; The next time you see an open flame, you’re not going to put your hand on it (unless you want to get burned). In that case, the action caused a reac­tion that peo­ple remember.
• Some sym­bol, icon, or other visual pre­sen­ta­tion type that allows the user to make a free asso­ci­a­tion with the task at hand. For exam­ple, the “Home” icon on most browser is a lit­tle house. The rea­son for this is that peo­ple assume that this house is their home. Thus the home con­cept is com­mu­ni­cated to them via a visual cue.

Test­ing for memorability

One of the chal­lenge on OSS devel­op­ment is that most of the devel­op­ment gen­er­ally hap­pens with­out user input. In order to estab­lish mem­o­ra­bil­ity, user input is needed. The only way to mea­sure how mem­o­rable a sys­tem can be is to sit a reg­u­lar user down in front of the sys­tem a few times. The first time, the user will get an idea as to how the sys­tem works and com­plete a set of estab­lished tasks.

After that first ses­sion, con­tinue cod­ing but do not change the inter­face (unless some­thing glar­ingly obvi­ous was shown to you by the user in terms of not work­ing). A few days later, sit the same user down in front of the sys­tem and ask him/her to com­plete the same set of tasks, this time with­out your assis­tance. If the user is fum­bling around, try­ing to fig­ure out how to move for­ward on a task, you have a mem­o­ra­bil­ity prob­lem: the user is not remem­ber­ing how to do a task. After that obser­va­tion cycle, talk to the user about the spe­cific task on which he/she stum­bled. From there, you might be able to guess what would make things more memorable.

How­ever, how one user remem­bers things is not enough to cre­ate a sys­tem that is mem­o­rable to all. As a result, using the same user over and over again will work great for that one user but may get fur­ther and fur­ther from mak­ing the sys­tem mem­o­rable for other users. As a result, you will have to run through the set of tasks quite a few times before you get a good han­dle on what most users will remember.