Measurements have always been a way of keeping track of whether something is working. As human beings we have done this ever since we first developed numerical measurement systems (perhaps even before then) and since online experience became such an important tool for business this has become even more the case. Learning to measure user experience is not only key for working out how we can improve the overall experience and satisfaction but also for quantifying exactly what is working and what isn't. With that in mind, here are a few of the Key Performance Indicators (KPIs i.e. the quantifiable measurements) that you should be tracking.
Task success is one of the most commonly used KPIs and basically measures the percentage of correctly completed tasks by users. This could be something such as signing up for a newsletter, buying a product or registering personal details. When the number of successful tasks is divided by the total number of attempts youâ€™ll be able to see how hard or difficult people find the task to complete.
Navigation or search is another important metric that will show you how the website is being used i.e. how many people are getting around the site using the designed navigation and how many are opting for search. Normally navigation is the first choice and then if that fails people will resort to search so if the metrics show a higher number of uses of search than navigation then the site design might need a rethink.
Error rates will show you have many times users are falling down while trying to complete a task, such as making a payment. You need to define here what will constitute a users failure and whether you're going to include a partial failure in your calculations. You might want to measure the total number of errors against the total number of opportunities for errors or alternatively the total number of errors against the total number of task attempts.
Conversion is of course the definitive metric when it comes to success and, although this is important, its also worth remembering that the conversion metric misses out those people who are almost ready to commit or interested in committing but haven't quite got there yet. If you can, widen out your metrics from conversion to include those who might imminently convert or who might be thinking about it for example, look at the likelihood of taking action on a micro conversion then you will get a broader, better picture.