GOMS Model on Instructional Design

Prepared By: Rekah VelooDate:16th Aug 2010Lecture: Dr. Balakrishnan MuniandyCourse Code: QIM 501E

AbstractDefinition: 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.

AbstractTraditional 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 ModelDeveloped in 1983 by:

Stuart Card, Thomas P. Moran & Allen NewellDescription 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

• 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.

• 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.

• 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.

Stuart Card Thomas P. Moran Allen Newell

Overview : GOMS Model

Goals (What the user

intends to accomplish)

Operators

(Actions that are performed to get to the

goal)

Methods (Sequences of operators that accomplish a

goal)

Selection Rules

(Used when user have more

than 1 methods )

GOMS

PrinciplesGoals

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.

OperatorBasic perceptual, cognitive, or motor actions used to

accomplish goals, or actions that the software allows user to make (e.g. PRESS-ENTER-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).

PrinciplesMethods

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 use-mouse-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-word-method, else use the use-mouse-delete-word method"

Scope & Application

•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.

Functionality Coverage

•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.

Execution Time

•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.

Help System

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:

GOMS EpistemologyLearning 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 systemthe motor systemthe cognitive system

Model Human Processor (MHP)

Model Human Processor (MHP)Receives inputs from the different devices such monitor & speakers

Apply the correct methods according to rules

Already familiar with the system-> retrieves information from long term memory

Instructional Design Process1.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.)

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.

Instructional Design Process

GOMS Variants

GOMS

Keystroke-Level Model (KLM)

Card, Morn, and Newell GOMS

(CMN-GOMS)

Natural GOMS Language (NGOMSL)

Cognitive-Perceptual-Motor GOMS

(CPM-GOMS)

Several variations of the GOMS model have been proposed to address issues with the original model.

Keystroke-Level Model (KLM)Simplest variant of GOMSKLM 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: KLMDescribe the task using the following

operatorsK: keystroke, mouse button pushP: point with pointing deviceD: move mouse to draw lineH: move hands to keyboard or mouseM: mental preparation for an operationR: system response time

Tasks split into two phases Acquisition of task - user builds mental

representative.Execution of task - using system facilities

Example: KLMDescription Operation Time (sec)

Reach for mouse H[mouse] 0.40

Move pointer to "Replace" button P[menu item] 1.10

Click on "Replace" command K[mouse] 0.20

Home on keyboard H[keyboard] 0.40

Specify word to be replaced M4K[word] 2.15

Reach for mouse H[mouse] 0.40

Point to correct field P[field] 1.10

Click on field K[mouse] 0.20

Home on keyboard H[keyboard] 0.40

Type new word M4K[word] 2.15

Reach for mouse H[mouse] 0.40

Move pointer on Replace-all P[replace-all] 1.10

Click on field K[mouse] 0.20

Total 10.2

According to this KLM model, it takes 10.2 seconds to accomplish this task.

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

CMN-GOMSThe 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-

operation-selection 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-GOMSGOAL: 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

NGOMSLNatural GOMS LanguageBuilds 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: NGOMSLGoal: Move a file into a subfolder in Windows XPMethod for accomplishing goal of moving a file using the drag and drop option:

Step 1: Locate the icon of the source file on the screenStep 2: Move mouse over the icon of the source fileStep 3: Press and keep holding the left mouse buttonStep 4: Locate the icon of the destination folder on the screenStep 5: Move mouse over the icon of the destination folderStep 6: Release left mouse buttonStep 7: Return with goal accomplished

Kieras, David (1996). "A Guide to GOMS Model Usability Evaluation using NGOMSL

Example: NGOMSLMethod 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 menuStep 3: Locate the icon of the source file on the screenStep 4: Accomplish the goal of selecting and executing the "cut" commandStep 5: Recall that the next command is called "paste"Step 6: Recall that the command "paste" is in the right click menuStep 7: Locate the icon of the destination folder on the screenStep 8: Double click with left mouse buttonStep 9: Locate empty spot on screenStep 10: Move mouse to the empty spotStep 11: Accomplish the goal of selecting and executing the "paste" commandStep 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-GOMSCognitive-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 GOMSThe 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.

ConclusionGOMS 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.

ReferenceWebsite

http://www.cs.umd.edu/class/fall2002/cmsc838s/tichi/goms.html

http://www.etutors-portal.net/Partners/eTutors-TRANSNET/OLD%20Language%20Folders/Romanian%20Language%20Folder/f1/Folder.2004-02-26.4226/LearningTheories.doc

http://tip.psychology.org/card.html http://www.cc.gatech.edu/computing/classes/cs6751_98_fall/ha

ndouts/GOMS-Kieras.html http://books.google.com.my/books?id=zOy0duJzDjQC&pg=PA1

11&lpg=PA111&dq=goms+instructional+design&source=bl&ots=BkH0rG_QfP&sig=BbcuVxlyRtGx0K2qoIYHZ3GQ8xU&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.