Time is a metric we all understand so it’s no wonder it’s one of the core usability metrics. Perhaps it’s something about the precision of minutes and seconds that demands greater scrutiny. There’s a lot to consider when measuring and analyzing task time. Here are 10 of them. Task times are collected in about half
Why spend more time completing a task when it could be done in less time? Users become very cognizant of inefficient interactions and this is especially the case with tasks that are repeated often. Task time is the best way to measure the efficiency of a task and it is a metric that everyone understands.
A key aspect of usability is efficiency. Users should be able to complete tasks quickly. Efficiency is usually measured as time on task, one of the quintessential usability metrics. For transactional tasks done repeatedly, shaving a couple seconds off a time can mean saving minutes per day and hours per week for users (think Accounting,
Recently Nielsen conducted a study on the reading speeds between the printed book, Kindle and iPad. From 24 users the study concluded that the iPad took about 6.2% longer (p =.06) and Kindle about 10% longer (p <.01) to read than the same story on a printed book. From this data Nielsen concluded “Books Faster
If you have an iPhone, you probably love it like I do. You probably also use it a lot like I do. The features and apps and, of course, the user interface make using the iPhone a rich and rewarding experience. Where I once had to wait till I got to my computer to send
It would be nice if all users completed tasks in a usability test. If they did you wouldn’t have to worry about what to do with their task times if they are unable to complete the task. But then again, if all your users had no problems completing tasks, you wouldn’t worry about improving usability.
How long does it take users to complete a task? We really don’t know. Instead we have to take our best guess from a sample of users. But if you had to pick a single number to summarize how long it would take typical users to complete a task from a usability test what would
While it might seem like having users think aloud while they complete a task will increase the time on task—the literature is actually mixed. Some studies report no difference, some show longer task times for thinking aloud and others report faster task times for thinking aloud. It has been hypothesized that the reason users can
How many users will complete the task and how long will it take them? If you need to benchmark an interface, then a summative usability test is one way to answer these questions. Summative tests are the gold-standard for usability measurement. But just how precise are the metrics? Just as a presidential poll uses a
It is common to think of time-on-task data gathered only during summative evaluations because, during a formative evaluation, the focus is on finding and fixing problems, or at least finding the problems and delivering a report. For a variety of reasons, time-on-task measures often get left out of the mix. In this article, I show