PSS Voice User Interface (VUI) Design and Evaluation Services optimize the overall customer experience and help your application achieve its intended goals. VUI design service are an integral part of the PSS Agile Speech Project methodology for building new applications. PSS also offers its VUI design expertise as a standalone professional service for improvement of existing applications or for new application development.
Heuristic evaluation is a method for evaluating a user interface early in the design process without direct input from end users. We examine the prompts, information architecture and navigation of the system, then evaluate each for clarity, consistency, simplicity, and conciseness. The PSS user interface specialist assumes the role of a typical user of the system and follows both positive paths and error conditions in the IVR. These interactions allow us to identify instances in which the VUI design deviates from accepted best practices.
We compile the heuristic evaluation results in a report that identifies issues with the VUI, categorizes and proritizes the issues, and recommends solutions. We present our recommendations as precisely as possible, suggesting specific design changes based on available information. When it is not possible to recommend a specific change to eliminate an issue, we provide detailed instructions on next steps required to gather the information needed to find a solution.
Tuning is a process of optimizing the perfomance of a speech application. Tuning involves recording real customer calls and analyzing them in order to identify issues that were not apparent in usability testing.
To conduct tuning, we use full call recordings of several hundred calls into the application. These are transcribed for analysis, and the transcriptions form the basis for computing statistics on speech recognition rates, and for analyzing in-grammar versus out-of-grammar responses.
We will use call recordings, transcriptions, and computed statistics to identify issues with recognition parameters, pronunciations, grammars, and prompts, then recommend changes to improve performance. The deliverable for tuning is a report identifying issues in detail with proposed solutions.
VUI design begins by collecting and analyzing all relevant data about any existing applications and identifying specific goals for any new applications. We consider call volumes, usage statistics, interviews with call center representatives, discussions with project sponsors, and review other customer-facing communications (e.g. website, printed materials.)
The first VUI deliverable is a preliminary design document that presents the results of the requirements analysis and proposes a strategy for the new design. We will propose new call flows, cmplete with menu structures and prompt text, along with representative use cases that demonstrate important aspects of application behavior (including error handling.) The preliminary design will be presented to the customer for approval.
The preliminary design wil be usability tested, and we use the results to modify the preliminary design and develop a complete design specification. The VUI design specification is the final design deliverable. We will also assis in the selection of suitable voice talent for recording prompts and coach the recording sessions as part of the VUI design services.
Usabilitiy testing is a method for observing users interacting with a speech application and collcting their opinions about their interactions. Usability testing provides a way to validate design changes by allowing us to observe users' responses to new prompts and call flow under controlled conditions.
Usability testing can be conducted in person at a market research facility or remotely over the phone. In either case, we recruit a group of test participants who are representative of the user population for the application being tested.
PSS will also develop a set of test scenarios that represent typical and frequent reasons customers call into the application. We conduct test sessions individually, and they typically last one hour each. Participants make a tst call into the applicaiton for each test scenario. After each call we interview participants to find out what they were thinking during the call and to get their reactions to each interaction scenario. At the end of the session each participant completes an opinion survey to rate the overall experience using the application. PSS produces a detailed usability report which identifies, categorizes, and prioritizes issues and proposed design solutions.