MAP-01-011 HFI Technical Guide - Human Factors Integration ...

Annex 3 – HF Techniques, Methods and Tools• Advantages• SUMI is a very quick and easy technique to use, requiring almost notraining.• The output of SUMI is very useful, offering an insight into the system usersattitudes regarding the systems usability.• If the correct sample is used, the systems potential users are in effectrating the usability of the system.• Once an operational system is available, the speed, ease and usefulnessof SUMI mean that it can be used again and again to evaluate and modifythe design concept.• Encouraging reliability and validity statistics.• SUMI statements can be added and removed in order to make the analysismore suitable for the software system in question.• Can be used effectively even with small sample sizes.• The scoring process is computerised.• SUMI is recognised by the ISO as a method for testing user satisfaction.• Disadvantages• Developed specifically for software systems containing a display, a datainput device and a peripheral memory device. If the system under analysisdoes not possess all of these facets, some modification of the SUMIstatements would be required.• Currently, the technique is only available commercially.A3.12.4.3System Usability Scale (SUS)SUS is a simplistic usability questionnaire, consisting of ten usability statementsthat are rated on a Likert scale of 1 (strongly agree with statement) to 5 (stronglydisagree with statement). The SUS is used to assess the usability of a product ordevice.Both the training and application times for the SUS technique are very low. Sincethe SUS scale uses only ten questions, it is very quick to train and apply.• Advantages• Very easy to use, requiring very little training.• Offers an immediately useful output in the form of a usability ‘rating’ for thedevice under analysis.• Very useful for canvassing user opinions of devices or products.May 2006 Page A3-121 Issue 4