Teori, Prinsip, dan Pedoman Materi Pertemuan Ke-2 Teori, Prinsip, dan Pedoman

Teori Tingkat Tinggi : Four Level Approach to design a piece of software or system. ( Foley dan Van Dam ) Conceptual When a user is working on an interactive system, a mental model is often developed Semantic When the user enters in input to the system, and the computer generates output based on that input. The Semantic level describes the meanings between the input and output Syntactic a set of rules to create a sentence, which will give the computer a set of instructions to complete a particular task Lexical deals with input device dependencies, in which the user will specify the exact syntax

Model mental manusia dari sistem interaktif Menggambarkan arti yang disampaikan oleh perintah yang dimasukkan pemakai dan keluaran yang dihasilkan komputer Mendefinisikan bgmn satuan (kata) yg menyampaikan semantik dirangkai menjadi kalimat lengkap yg memerintahkan komputer melakukan tugas tertentu Berhubungan dengan ketergantungan terhadap piranti

CONTOH : Conceptual: Provides a mental model Example: text editor objects = characters, files, paragraphs relationships = files contain paragraphs contain chars operations = insert, delete, etc. Semantic: meaning/desired function Example: move the paragraph Syntactic: how the semantic command is formed Example: prefix vs. postfix (Edit, Highlight, Cut, Paste) Lexical: sequence of actions Example: how mouse and keyboard combined into menu, button, string, pick, etc. Point to edit on menu bar->click ->select option within edit menu.

GOMS Model analyzes the user complexity of interactive systems GOMS Model analyzes the user complexity of interactive systems. It is used by software designers to model user behavior. ( Card, Moran, and Newell ) Goals edit dokumen (subgoals = Insert word) Operators Tekan tombol panah atas Pindahkan tangan ke mouse Ingat nama file Pastikan kursor ada di akhir baris Method Pindahkan kursor ke lokasi yg diinginkan dgn serentetan penekanan tombol panah Selection Rules Menghapus dengan backspace berkali-kali vs. memblok dan menekan tombol delete

Goal End state trying to achieve Then decompose into subgoals Select sentence Moved sentence Cut sentence Move to new spot Paste sentence Place it

Operators Basic actions available for performing a task (lowest level actions) Examples: move mouse pointer, drag, press key, read dialog box, … Fall 2002 CS/PSY 6750

Methods Sequence of operators (procedures) for accomplishing a goal (may be multiple) Example: Select sentence Move mouse pointer to first word Depress button Drag to last word Release Fall 2002 CS/PSY 6750

Selection Rules Invoked when there is a choice of a method GOMS attempts to predict which methods will be used Example: Could cut sentence either by menu pulldown or by ctrl-x Fall 2002 CS/PSY 6750

Seven stages of action ( Norman ) Bentuk Goal Bentuk intention Sebutkan aksi Laksanakan aksi Perhatikan keadaan sistem Interpretasikan keadaan sistem Evaluasi keluaran

Model sintaktik & semantik dari pengetahuan pemakai Sintactic Knowledge Sifatnya : Berbeda antara sistem Tidak dapat diramalkan Penghafalan berulang-ulang Mudah dilupakan Struktur tidak jelas

Semantic Knowledge Sifatnya : Terorganisasi secara hierarkis Dari pelajaran/analogi Tidak tergantung sintaksis Stabil dalam ingatan pemakai

Semantic Knowledge dibedakan menjadi : Computer concepts Computer Objects High level : Storage information Lower Level : File Directory Computer Actions High Level : file text edit Lower Level : open file, input text, save file

2. Task Concepts Task Objects : Task Actions : High Level : mail Lower Lever : date, address, signature Task Actions : High Level : writing mail Lower Level : Spelling

Tiga Jenis Pemakai Novice or first time users Knowledgeable intermittent users Expert frequent users

Tidak punya syntactic knowledge, semantic knowledge sedikit Pengetahuan mengenai tugas dangkal Punya semantic knowledge atas task concep dan computer concept Kesulitan dengan syntactic knowledge Kenal betul dengan aspek syntactic dan semantic Ingin pekerjaan cepat selesai

Delapan aturan emas perancangan dialog Berusaha keras u/ konsisten Memungkinkan frequent user menggunakan shortcut Umpan balik informatif Merancang dialog u/ menghasilkan keadaan akhir (sukses, selesai) Penanganan kesalahan sederhana Mengizinkan pembalikan aksi (undo) Mendukung internal locus of control Mengurangi beban ingatan jangka pendek

Mencegah kesalahan Correct matching pairs Tanda pembuka & penutup dalam satu aksi Mengingatkan pemakai tanda penutup blm dipasang Menghilangkan keharusan tanda penutup

Complete sequences Correct commands Menggabungkan aksi Melakukan aksi tergantung aksi lain secara otomatis Correct commands Melengkapi kekurangan perintah Memberikan pilihan