Usability Testing — The DATech Standard

The DATech Standard Usability Test is devoted to the conformity and nonconformity of software with usability standards (ISO 9241 Parts 10 and 11). The methods are intended for usabil­ ity experts. The professional tester of software is guided to restrict the test effort to those require­ ments that can be derived as being objective and valid. A statement on conformity is thus confined to the list of such requirements. On this basis the results achieved with a test are reproducible. A complete product test, as suggested by the verification approach of ISO 9241, can hardly be put into practice cost-effectively. Therefore, according to the DATech approach a product's conformity with standards is being presumed until the reverse has been verified (so-called falsification approach). Such a proof is always linked to objective requirements derived from the context of use and user performance. Adhering to this test approach a product can be claimed as usable. If a deviation from the standard is suspected, it has to be proven by means of a separate procedure. In this case the im­ pact of a suspected deviation on user performance is looked into. The virtue of this approach is not only seen in the stated defects and related impacts but also in its constructive contribution to qual­ ity improvement. Every ergonomic improvement helps save usage costs. Nowadays, it is not the purchase costs that "gives the user a headache" but the mostly underestimated usage costs. The ap­ plication of the test method can therefore contribute to reduce these costs and simultaneously im­ prove the quality of work.