Evalueringsformer i HCI Design & evaluering Design og evaluering integrerede aktiviteter (studér kundernes arbejde - designe - evaluér - iterér) Teknikker til design omfatter: Opgave/arbejdsanalyser Brugerinddragelse, fx brugercentret udvikling, prototyping og kontekstuel design Videnskabelige tommelfingerregler (heuristikker)
Sigchi curriculum www.sigchi.org/cdg/
Design & evaluering Evaluering kan foretages ved: Formative evalueringer User testing, for eksempel tænke-højt forsøg Egentlige eksperimenter Analytisk, fx ud fra retningslinier for brugsvenlighed
Brugsvenlighed & anvendelighed Brugsvenlighed omfatter normalt (ISO): Effektivititet, fx kvalitet Produktivitet, fx tid Tilfredshed, fx hvad foretrækker bruger
Evalueringsformer i HCI hos Shneiderman Ekspert review Usability test (brugsvenlighedstest) samt laboratorie- og feltafprøvninger Spørgeskemaundersøgelser Godkendelsestest store udviklingsprojekter Evalueringsaktiviteter daglige systemdrift og brug Kontrollerede eksperimenter kombinationen af de psykologiske og de datatekniske aspekter ved interaktionen.
Shneiderman Chap 4: Expert Reviews, Usability Testing, Surveys, and Continuing Assessment 4.1 Introduction Designers entranced with their creations may fail to evaluate them adequately Experienced designers have attained the wisdom and humility to know that extensive testing is a necessity The determinants of the evaluation plan include: - stage of design (early, middle, late) - novelty of project (well defined vs exploratory) - number of expected users - criticality of the interface - costs of product and finances allocated for testing - time available - experience of the design team
Shneiderman 4.2: Expert Reviews While informal demos to colleagues or customers can provide some useful feedback, more formal expert reviews have proven to be effective Expert reviews entail one-half day to one week effort, although a lengthy training period may sometimes be required to explain the task domain or operational procedures There are a variety of expert review methods to chose from: - Heuristic evaluation - Guidelines review - Consistency inspection - Cognitive walkthrough - Formal usability inspection
...Expert Reviews Expert reviews can be scheduled at several points in the development process when experts are available and when the design team is ready for feedback Different experts tend to find different problems in an interface, so 3-5 expert reviewers can be highly productive, as can complementary usability testing The dangers with expert reviews are that the experts may not have an adequate understanding of the task domain or user communities Moreover, even experienced expert reviewers have great difficulty knowing how typical users, especially first-time users will really behave
4.3: Usability Testing and Laboratories 4.4: Surveys 4.5: Acceptance Tests 4.6: Evaluation During Active Use 4.7: Controlled Psychologically-oriented Experiments
Kriterier for udvælgelse af konkrete HCIevalueringsformer Tilstræb størst mulig Generaliserbarhed Præcision Realisme Ingen enkelt evalueringsform er optimal i alle henseender - kombiner & vurder samstemmighed (Joseph McGrath, 1994 - in Readings in HCI)
2.5 Eight Golden Rules of Interface Design Consistency Shortcuts Feedback Yield closure Error prevention & simple error handling Easy reversal Locus of control Reduce memory load
Shneiderman 2.4 Recognize Diversity Usage profiles (e.g. novice or first-time users; knowledgeable intermittent users; expert frequent users) Task profiles (e.g. frequency of task by job title) Interaction styles (e.g. direct manipulation; menu selection; form fill-in; command language; natural language)
Naurs trekant (1965) HCI handler om samspillet mellem brugere, redskaber og opgaver. Sker i org./samfund Redskaber Brugere Opgaver Organisation/samfund 8
Hvad er HCI? HCI er: a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them, Hewett et al. (1992) Handler for mig om at lave systemer som støtter menneskers aktiviteter 2