Baseline experience testing gives you a qualitative baseline of how usable your product or service offering is for users and identifies areas that need design improvements. Representative users are given realistic tasks to accomplish while a study moderator observes and identifies usability problems. A baseline experience test, along with a usability inspection such as a heuristic review, is a good way to introduce usability in your organization.
Sample sizes of 8-14 study participants are generally used in baseline experience testing. Though primarily qualitative by design, some quantitative indicators such as task success rates and satisfaction scores are often reported in these studies.
With larger samples of 15 or more study participants, usability performance testing can establish quantitative benchmark metrics for a product, including time on task, error rates, completion rates, user satisfaction scores, and others. Larger samples are required when statistical confidence is needed in the accuracy of results. Performance tests can be replicated to quantify design improvements between development builds or releases, compare performance against competing products, or assess more than one potential design in “A/B” testing.