GOMS Model - Instructional Design & delivery / 2010 + Research

Report
Prepared By: Rekah Veloo
Date:16th Aug 2010
Lecture: Dr. Balakrishnan Muniandy
Course Code: QIM 501E
Abstract
 Definition: Instruction Design
 A systematic development of instructional specifications
using learning and instructional theory to ensure the
quality of instruction. It is the entire process of
analysis of learning needs and goals and the
development of a delivery system to meet those
needs.
Abstract
 Traditional Approach:
 A subject is observed in order to record the different
task, actions and time is needed to perform a specific
task.
 Result will use to define metrics and to optimize the
workflow.
 Modern Approach:
 Computer as a mean to deliver instruction, the task
analysis has been redesigned in order to consider human
computer factors.
Overview :GOMS Model
 Developed in 1983 by:
 Stuart Card, Thomas P. Moran & Allen Newell
 Description of the Model:
Kind of specialized human information processor model
for human computer interaction observation and predict
user behavior. Typically used by software designers.
The knowledge and skills that a user must have in order to
carry out task on a device or system. (Kieras, 1988)
It is representation of “how to do it” knowledge that is
required by a system in order to get intended task
completed.
Believed applied information processing psychology
should be based on task analysis, calculation and
approximation.
Biography
Stuart Card
• An American researcher
and Senior Research
Fellow at Xerox PARC
• Received a A.B. in physics
from the Oberlin College
in 1966, and a Ph.D. in
psychology from
Carnegie Mellon
University.
• In 2000 he was awarded
the CHI Lifetime
Achievement Award from
the Association for
Computing Machinery's
SIGCHI,
• Has been one of the
pioneers of applying
human factors in
human–computer
interaction.
Thomas P. Moran
• Distinguished Engineer
at the IBM Almaden
Research Center near San
Jose, California
• He founded and has been
Editor-in-Chief of
Human-Computer
Interaction.
• First CHI Academy
members and won ACM
SIGCHI's 2004 Life Time
Achievement Award
• In 2003 he was inducted
as a Fellow of the
Association for
Computing Machinery.
Allen Newell
• Researcher in computer
science and cognitive
psychology at the RAND
corporation and at
Carnegie Mellon
University.
• He was awarded the
ACM's A.M. Turing
Award along with
Herbert Simon in 1975 for
their basic contributions
to artificial intelligence
and the psychology of
human cognition.
Overview : GOMS Model
Goals
Operators
(What the user
intends to
accomplish)
(Actions that are
performed to get
to the goal)
GOMS
Selection
Methods
Rules
(Sequences of
operators that
accomplish a
goal)
(Used when user
have more than 1
methods )
Principles
Goals
Something that the person wants to accomplish. Can be high level
(e.g. WRITE-PAPER) to low level (e.g. DELETE CHARACTER)
High level goals are decomposable into sub goals, and are arranged
hierarchically.
Operator
Basic perceptual, cognitive, or motor actions used to accomplish
goals, or actions that the software allows user to make (e.g. PRESSENTER-KEY or CLICK-MOUSE).
Not decomposable: they are atomic elements in the GOMS model.
It is generally assumed that each operator requires a fixed amount
of time for the user to execute, and that this time interval is
independent of context (e.g. CLICK-MOUSE button takes 0.20
seconds to execute).
Principles
Methods
 Procedures (sequences) of sub goals and operators that can
accomplish the goals.
 E.g: one method to accomplish the goal DELETE-WORD in the
“Emacs” text editor would be to MOVE-MOUSE to the beginning of
the word, and PRESS-ALT-D-KEY-COMBINATION (the usemouse-delete-word method). Another method to accomplish the
same goal could involve using the arrow keys to reach the beginning
of the word (the use-arrows-delete-word method).
 Selection Rules
 Personal rules users follow in deciding what method to use in a
circumstance.
 E.g:"if the word to be deleted is less than 3 lines away from the
current cursor location, then use the use-arrows-delete-wordmethod, else use the use-mouse-delete-word method"
Scope & Application
Provides the designer with a model of a user’s behavior while performing well
known task, whereby these models can be used for a variety of purposes:
Functionality
Coverage
• If the designer has a list of likely user goals, GOMS models can
be used to verify that a method exists to achieve each of these
goals.
Execution
Time
• GOMS models can predict the time it will take for the user to
carry out a goal (assuming an expert user with no mistakes).
• This allows a designer to profile an application to locate
bottlenecks, as well as compare different UI designs to
determine which one allows users to execute tasks quicker.
Help System
• GOMS models are an explicit representation of expert user
activity, they can assist in designing help systems and tutorials
to assist users in achieving goals.
GOMS Epistemology
 Learning involve knowledge acquisition & it is
important to recognize the different sources of
knowledge and the epistemology involve.
 When a person use a system or device, the knowledge
is obtained through a sensory experience. Whereby
knowledge come from outside the learner and its
known through the continuous use of the tool.
 In GOMS, the interaction between a computer and
human being used 3 different stages on memory:
 perceptual system
 the motor system
 the cognitive system
Model Human Processor (MHP)
Model Human Processor (MHP)
Receives inputs from the different
devices such monitor & speakers
Already familiar with the
system-> retrieves
information from long
term memory
Apply the correct
methods according to
rules
Instructional Design Process
1. Choose user’s goals
 Objective: Determine what the learners needs to know / accomplish
after the instruction. Provide the inputs for training materials which
used to analyze the learn ability factors of the system & provide
feedback to the system designers to consider a redesign on the user
interface.
2. Perform the following recursive procedures:
 Draft a method to accomplish each goal by simply listing the steps
as general or high-level as possible for the current level of analysis
and by passing complex psychological process.
 Check each step and rewrite as needed for conformance to
guidelines. (includes checking on method detail & length,
consistency in assumptions about users skill level, and that each
high-level operator corresponds to a natural goal.)
Instructional Design Process
 If needed, go to lower level of analysis by changing the higher-level
operators, and then provide methods for the corresponding goals.
At the bottom all operators are primitives. If they are not , then
need to decide whether to provide a methods for performing it.
3. Document & check the analysis


List all primitive external operators used, analyst-defined
operators, assumptions, & judgment call made.
Should check the accuracy if the model by executing the methods
as carefully as possible. Make sure that the methods procedure
the outcomes on the system.
4. Check sensitivity of judgment calls and assumptions
made during the analysis.
GOMS Variants
 Several variations of the GOMS model have been proposed to address issues
with the original model.
Card, Morn, and Newell GOMS
(CMN-GOMS)
GOMS
Keystroke-Level Model
(KLM)
Natural GOMS Language
(NGOMSL)
Cognitive-Perceptual-Motor GOMS
(CPM-GOMS)
Keystroke-Level Model (KLM)
 Simplest variant of GOMS
 KLM model applications :
 mouse-driven text editors.
 workstations for directory-assistance telephone
operators.
 space operations database systems.
 CAD/CAM software.
 This model is unsuited to analyzing more abstract
tasks such as EDIT-MANUSCRIPT, which involve
conditionals and decomposition into sub goals.
Example: KLM
 Describe the task using the following operators
 K: keystroke, mouse button push
 P: point with pointing device
 D: move mouse to draw line
 H: move hands to keyboard or mouse
 M: mental preparation for an operation
 R: system response time
 Tasks split into two phases
 Acquisition of task - user builds mental representative.
 Execution of task - using system facilities
Example: KLM
Text editing task of searching a Microsoft Word document for all occurrences
of a four-letter word, and replacing it with another four-letter word
Description
Reach for mouse
Move pointer to "Replace" button
Click on "Replace" command
Home on keyboard
Specify word to be replaced
Reach for mouse
Point to correct field
Click on field
Home on keyboard
Type new word
Reach for mouse
Move pointer on Replace-all
Click on field
Total
Operation
H[mouse]
P[menu item]
K[mouse]
H[keyboard]
M4K[word]
H[mouse]
P[field]
K[mouse]
H[keyboard]
M4K[word]
H[mouse]
P[replace-all]
K[mouse]
Time (sec)
0.40
1.10
0.20
0.40
2.15
0.40
1.10
0.20
0.40
2.15
0.40
1.10
0.20
10.2
According to this KLM model, it takes 10.2 seconds to accomplish this task.
CMN-GOMS
 The original GOMS model proposed by Card, Morn and





Newell (1983)
Builds on KLM by adding sub goals and selection rules.
This technique requires a strict goal-method-operationselection rules structure.
Can predict operator sequence as well as execution time.
Can be represented in program form, making it amenable
to analysis as well as execution.
CMN-GOMS Model application:
 model word processors (Card et. al, 1983)
 CAD system for ergonomic design(John & Kieras, 1996)
 Sun Microsystem's web page.
EXAMPLE: CMN-GOMS
GOAL: DELETE-FILE
.
GOAL: SELECT-FILE
.
.
[select: GOAL: KEYBOARD-TAB-METHOD
.
.
GOAL: MOUSE-METHOD]
.
.
VERIFY-SELECTION
.
GOAL: ISSUE-DELETE-COMMAND
.
.
[select*: GOAL: KEYBOARD-DELETE-METHOD
.
.
.
PRESS-DELETE
.
.
.
GOAL: CONFIRM-DELETE
.
.
GOAL: DROP-DOWN-MENU-METHOD
.
.
.
MOVE-MOUSE-OVER-FILE-ICON
.
.
.
CLICK-RIGHT-MOUSE-BUTTON
.
.
.
LOCATE-DELETE-COMMAND
.
.
.
MOVE-MOUSE-TO-DELETE-COMMAND
.
.
.
CLICK-LEFT-MOUSE-BUTTON
.
.
.
GOAL: CONFIRM-DELETE
.
.
GOAL: DRAG-AND-DROP-METHOD
.
.
.
MOVE-MOUSE-OVER-FILE-ICON
.
.
.
PRESS-LEFT-MOUSE-BUTTON
.
.
.
LOCATE-RECYCLING-BIN
.
.
.
MOVE-MOUSE-TO-RECYCLING-BIN
.
.
.
RELEASE-LEFT-MOUSE-BUTTON]
*Selection rule for GOAL: ISSUE-DELETE-COMMAND
If hands are on keyboard, use KEYBOARD-DELETE-METHOD, else if Recycle bin
is visible, use DRAG-AND-DROP-METHOD, else use DROP-DOWN-MENU-METHOD
NGOMSL
 Natural GOMS Language
 Builds based on CMN-GOMS by providing a natural-
language notion for representing GOMS models.
 Methods are represented in terms of an underlying
cognitive theory known as cognitive complexity theory,
or CCT.
 This cognitive theory allows NGOMSL to incorporate
internal operators such as manipulating working
memory information or setting up sub goals.
 NGOMSL also can be used to estimate the time
required to learn how to achieve tasks.
Example: NGOMSL
Goal: Move a file into a subfolder in Windows XP
Method for accomplishing goal of moving a file using the drag and drop
option:
Step 1: Locate the icon of the source file on the screen
Step 2: Move mouse over the icon of the source file
Step 3: Press and keep holding the left mouse button
Step 4: Locate the icon of the destination folder on the screen
Step 5: Move mouse over the icon of the destination folder
Step 6: Release left mouse button
Step 7: Return with goal accomplished
Kieras, David (1996). "A Guide to GOMS Model Usability Evaluation using NGOMSL
Example: NGOMSL
Method for accomplishing goal of moving a file using the cut and paste
option:
Step 1: Recall that the first command is called "cut"
Step 2: Recall that the command "cut" is in the right click menu
Step 3: Locate the icon of the source file on the screen
Step 4: Accomplish the goal of selecting and executing the "cut" command
Step 5: Recall that the next command is called "paste"
Step 6: Recall that the command "paste" is in the right click menu
Step 7: Locate the icon of the destination folder on the screen
Step 8: Double click with left mouse button
Step 9: Locate empty spot on screen
Step 10: Move mouse to the empty spot
Step 11: Accomplish the goal of selecting and executing the "paste" command
Step 12: Return with goal accomplished
 Selection rule set for goal: Move a file into a subfolder in Windows XP

If custom icon arrangement is used Then accomplish goal: cutting-and-pasting.
 If no custom icon arrangement is used Then accomplish goal: drag-and-drop.
 Return with goal accomplished.
CPM-GOMS
 Cognitive-Perceptual-Motor GOMS (CPM-GOMS)
 builds on previous GOMS models by assumed that
perceptual, cognitive and motor operators can be
performed in parallel.
 It employs a schedule chart (also known as a PERT
chart) to represent operators and dependencies
between operators.
Example: CPM-GOMS
CPM-GOMS model, John & Kieras (1996b.)
Advantage of GOMS
 The learn ability factors is measured based on the
time or effort that it takes to a user to get used to the
system and its operation.
 Includes how easy to remember some operational
steps in order o complete a task.
 Analysis provide quantitative and qualitative
information.
 Training programs and help systems can be built based
on the description of the knowledge needed to
perform a task, producing a task oriented document.
Conclusion
 GOMS is a model/technique used to analyze the
human computer interaction process.
 It uses not only discover the cognitive model of an user
interacting with a system but it also provides the
mechanism to estimate learning time, time on task
and probability of errors.
 It also demonstrates that the information processing
system plays an important role on the human
computer interaction.
Reference
 Website
 http://www.cs.umd.edu/class/fall2002/cmsc838s/tichi/goms.html
 http://www.etutors-portal.net/Partners/eTutors-
TRANSNET/OLD%20Language%20Folders/Romanian%20Language%20Fo
lder/f1/Folder.2004-02-26.4226/LearningTheories.doc
 http://tip.psychology.org/card.html
 http://www.cc.gatech.edu/computing/classes/cs6751_98_fall/handouts/G
OMS-Kieras.html
 http://books.google.com.my/books?id=zOy0duJzDjQC&pg=PA111&lpg=PA1
11&dq=goms+instructional+design&source=bl&ots=BkH0rG_QfP&sig=Bbc
uVxlyRtGx0K2qoIYHZ3GQ8xU&hl=en&ei=OedlTPLoMsiecaPjgbIK&sa=X&
oi=book_result&ct=result&resnum=1&ved=0CBgQ6AEwAA#v=onepage&q
=goms%20instructional%20design&f=false
 Article:
 GOMS Theory and its use on the Instructional Design Process, Maricel
Medina-Mora.

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