A/B testing is a type of testing where there are two different application designs, generally websites, that are tested over time. Data is collected on their performance with some sort of goal in mind such as product sales. If analytics show that one of the designs was better at achieving that goal then one is declared superior and is chosen as the design to go with. This can lead to even more A/B testing against other designs until the development team comes to a decision. The analytics for the test is often times done through third-party tools rather than an in-house solution. An A/B test can be as specific as you want, to the point where you only change a single small element between the two designs or they can be made completely different. It is often best to define a specific problem keeping you from your goal that you want to investigate such as users failing to complete a transaction. A/B testing is extremely clear-cut at providing measurement data for design decisions but can take a large amount of time to conduct the tests and produce the data.
Design Prototype Testing
Design prototype testing can be used to test a complete workflow in a wireframe or fully designed portion of a product before it goes into development. A UX/UI designer will create the prototype and the test will help fix usability issues before the project goes any further. It is important to define a budget for the project as well as the specific goal. Then you need to choose a prototyping tool such as Axure. Third, you will need to choose a measuring tool to gather analytics from the user such as Loop11. It is important that the development team is familiar with such tools to make the test worth the time and work investment put into the test.
Formative Usability Testing
Formative Usability Testing is a type of early-stage testing that focuses more on quality assurance. This test should occur before the first release of the developed product so that it can become the baseline for future tests. With formative usability testing the product will go through a beta test where groups perform the defined usability tests. Test cases are usually written down in order to inform the participants through specific goals in order to get meaningful results. Afterwards it is important to analyze the feedback and make revisions to the product before the official launch. This can be repeated in order to improve the product over time.