Human Computer Interaction
Usability Testing – Tes Kebergunaan
Objective Usability Testing 1-2
Apa itu Usability? Apa itu Usability Testing? Mendesain test Persiapan dalam testing Melakukan Testing Mengolah Data Hasil Testing
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Apa itu Usability? 1-3
Usability is the measure of the quality of a user’s experience when interacting with a product or system. (Usability.gov, 2006)
Usability is a quality attribute that assesses how easy user interfaces are to use. (Nielsen, 2003) The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use. (ISO standard 9241-11, 1998)
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Pengujian antarmuka pemakai diperlukan untuk menghindari penyimpangan-penyimpangan dari apa yang diinginkan klien (harus sesuai requirement)
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Apa itu Usability? 1-5
Mudah dipelajari —Seberapa cepat seorang user bisa mempelajari untuk menyelesaikan sebuah tugas dasar? Efisien—Seberapa seorang user yg cepat ‘berpengalaman’ menyelesaikan tugas-tugas? Mudah diingat—Bisakah seorang user mengingat bagaimana menggunakan sistem secara efektif pada penggunaan berikutnya? Error frequency and severity—Seberapa sering user melakukan kesalahan, seberapa serius kesalahan, dan bagaimana user bisa memperbaiki kesalahan? Kepuasan subjective—Apakakah user suka menggunakan sistem?
What is Usability? 1-6
Kualitas dari pengalaman Excellence
of user experience Nielsen’s ease of use/ website example
Frekuensi kesalahan/Kepuasan pengguna Quantitative
analysis Qualitative analysis
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Let’s watch
What is Usability Testing? 1-8
Merupakan proses terstruktur yang digunakan untuk mengetahui interaksi antara seorang objek pastisipan dengan tujuan sebuah desain. Paper and pencil (paper prototype) Heuristic
evaluation Cognitive walkthrough
Usability Lab (functional prototype) Formal
testing with subjects
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Cognitive walktrough 1-9
Heuristic evaluation 1-10
Heuristic evaluation is a user-centered method, which is different from the cognitive walkthrough as a task-oriented technique.
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What is Usability Testing? 1-11
Atribut yang biasa digunakan dalam hampir semua jenis usability test : The goal is to improve a product (Tujuan adalah untuk meningkatkan kemampuan produk) Participants are real users (peserta tes merupakan user yang sebenarnya) The participants do real tasks (peserta melakukan task/tugsa yang sebenarnya) Participants are formally observed (peserta harus mengobservasi secara resmi) The data are analyzed (data hasil tes dianalisis) Recommendations for improvement are made (dihasilkan rekomendasi dlm usaha peningkatan kualitas)
Dumas and Redish (1999)
What is Usability Testing? 1-12
A usability test has three basic components: Participants(peserta)—Actual
users who are asked to perform realistic and representative tasks using a proposed design
Design(desain)—May
be a fully functioning prototype or a simple paper prototype
Tester—There
might be only one tester or there might be a
testing team
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What is Usability Testing? 1-13
Constraints on Usability Testing Waktu Design Prepare Administer
(an hour to an hour and a half) Analyze the results Finance
(keuangan)
Equipment
and software Laboratory time Recording media Participant compensation Refreshments
What is Usability Testing? 1-14
Constraints on Usability Testing Personnel
(jumlah peserta)—Formal usability tests require at least four people.
Laboratory—To
perform a formal usability test, a dedicated laboratory is required.
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What is Usability Testing? 1-15
Human Subjects Protocols You
must be fully aware of the regulations imposed by the various institutions and regulatory bodies that pertain to your experimental design
The
U.S. Department of Health and Human Services Web site http://www.hhs.gov/ohrp/
What is Usability Testing? 1-16
Keuntungan Minimize
help desk calls – mengurangi bantuan Increase product loyalty – meningkatkan loyalitas penggunaan produk Provide benchmarks for future products – jaminan untuk produk selanjutnya
Batasan Artificial
context – konteks buatan Not definitive of product acceptance Skewed sample of users Not always efficient
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What is Usability? – Fase-fase Usability Test 1-17
Desain test Persiapan test Melakukan test Memproses data hasil test
Design the Test 1-18
Why: Define the Purpose/Tujuan What: Define Your Concerns and Goals/Pertimbangan dan tujuan anda What: Define the Tasks/Definisikan tugas(fungsi) What: Create the Scenarios/buat skenario What: Define the Measurements/Deskripsikan pengukuran How: Define the Test Method/Pilih metode tes
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Usability and ISO 9241 1-19
Usability Objective
Measures for Effectiveness
Measures for Efficiency
Measures for User Satisfaction
Suitability
Percentage of goals Completion time achieved
Rating scale for satisfaction
Appropriateness
Num of advanced features used
Relative efficiency vis-à-vis an expert
Rating scale
Learn-ability
Percentage of functions learnt
Time/tries to learn
Rating scale
Error Tolerance
Percentage of errors corrected
Time/tries spent on correction
Rating scale
Additional Objective : Esthetics
What to Measure: Example metrics 1. 1-20
2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
Time to complete the task, KLM, Fitts’ Law Number of commands involved Percent of task completed / unit time Number of errors committed Error density Number of errors discovered and corrected Number of times user needed help or guidance Time spent in correction Number of times user is mislead Number of tries needed for training Time needed for training Error reduction rate, Learning curve characteristics User satisfaction
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Design the Test
Where: Determine the Location of the Tests
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Usability lab with observers watching a user & assistant
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Design the Test 1-23
Who: Select Participants, Testers, and Observers
Design the Test 1-24
Participants should be real users You do not always need to test a great many users
The people you recruit should have the following basic characteristics: Availability Responsiveness Objectivity
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Design the Test 1-25
Yang berperan sebagai tester : Administrator Moderator Data
logger Technician Prototype expert
Potential observers include the following: Other
design team members not involved in the test
Clients Programmers
responsible for the final product
Prepare for the Test 1-26
Kapan : membuat sebuah jadwal test Project
level Test preparation level Test execution level Task execution level
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Prepare for the Test 1-27
Writing Scripts Greeting
the Participant Preliminary Interview Providing Instructions Monitoring the Test Debriefing the Participant
Perform the Test 1-28
Test Phases Pre-Test Menyapa
peserta tes Peserta menandatangani beberapa form yang dibutuhkan Peserta mengisi beberapa pertanyaan / kuesioner awal Diproses dengan script During
the Test
Maintain
a log or observation check list for each task. a problem list to capture anything that is not covered by the check list. Notate problems and jot down any hypotheses that occur to you about the problems. Create
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Perform the Test 1-29
Test Phases Post-Test Debrief
the participant.
post-test questionnaire verbal interview
Thank
the participant and provide compensation. Collect, summarize, and organize test data. Reset the room for the next participant.
Process the Data 1-30
Aktifitas yang dilakukan pada hari test Collecting
Data-mengumpulkan data Summarizing Data-menyimpulkan data Organizing the Material
Follow-Up Activities Categorizing
- mengkategorisasi
Analyzing Quantitative
Data Qualitative Data
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Process the Data 1-31
Dokumentasi Identifikasi
Masalah
Severity Frequency Errors
of omission Errors of commission Membagi
masalah dalam beberapa prioritas Mengkonsepkan alasan Mengkonsepkan solusi Identifikasi keberhasilan Identifikasi area yang belum pasti/kurang jelas
Usability Checklist http://www.weinschenk.com/knowledge/thoughts/thoughts_apr98.asp
1.Are there 9 or fewer areas on the page for visitors to focus on, or are there too many areas on the screen competing for visitors‘ attention? 2.Are there 9 or fewer items in lists or groups, or if more than 9 are they broken up into categories, or do visitors have to scan long lists?
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Checklist (cont.) 3.Can visitors read the text, or is a background color or texture interfering with the readability? 4.Does the layout of the screen encourage visitors to move their eye focus in a logical, orderly fashion, or are visitors visually lost?
Checklist (cont.) 5.Is the site designed with a particular target audience in mind, or is it trying to be all things to all people (and therefore nothing to nobody)? 6.Does the order visitors move through a page, or set of pages, match the way they want to do their work, or do visitors get lost trying to find information or fill out a form?
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Checklist (cont.) 7.Do you have the most important information at the top, or do visitors have to scroll to get to anything of importance. 8.Do you have the right amount of layers - enough to organize the material well and reduce decision making, but not so many layers that it takes too many clicks to get to meaningful information.
Checklist (cont.) 9.Do you know the purpose of the site, or has the site grown appendages that don't hang together? 10.Have you chosen the best content type (text, graphics, audio...) for the material and the hardware and software environment of your target audience, or is your content presented inappropriately?
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