# Presentation: 066111

## The Max Model: A Standard Web Site User Model

**The Max Model: ****A Standard Web Site User Model**

**Gene Lynch & Susan Palmiter**
**Design Technologies, Inc. **
**Chris Tilt**
**WebCriteria, Inc.**

## Problem / Opportunity

- Web site usability is critical to success
- Running usability tests on a web site of interest and on those of its competitors is often prohibitively expensive and is often too time consuming to be feasible in “Internet time.”

## Goals for automated metric

- Measure critical aspects of web site usability
- Base metric on human experience and behavior
- Provide stable, repeatable measures
- Communicate a singular metric

## Standard Observers

- COLOR:
- CIE Standard Observer: A hypothetical observer having the tristimulus color mixture data recommended in 1931 by the CIE for a 2° viewing angle.

## Standard Observers

- NOISE LEVEL:
- The ear does not respond equally to frequencies.
- Reduce the effects of the low and high frequencies.
- The resultant sound level is said to be A-weighted, and the units are dB.  A popular method of indicating the A-weighted units is dBA. The A-weighted sound level is also called the noise level.

## Challenge

- Create a standard Web Site User
- Make comparative web site measures
- Measure meaningful aspects critical to web site success
- Model intentional behavior
- Provide a single number metric

## Max

- Cultural
- Characteristics

- Max:
- Personal Profile

- Max:
- System Profile

- Max:
- Cognition

- Training and
- Experience

- Psychological
- Characteristics

- System
- Characteristics

- Internet
- Connectivity

- Max (Maxwell or Maxine)
- web site use behavior model

## Max: The Model (GOMS)

- Goals
- Operators
- Methods
- Selection rules
- Card, Moran, & Newell (1983)

## Max

- Cultural
- Characteristics

- Max:
- Personal Profile

- Max:
- System Profile

- Max:
- Cognition

- Training and
- Experience

- Psychological
- Characteristics

- System
- Characteristics

- Internet
- Connectivity

- Max (Maxwell or Maxine)
- web site use behavior model

## Max’s Personal Profile

- Psychological Characteristics
- 7 chunks in short term memory
- Remembers only previous page structure
- Training and Experience
- works on visible view
- doesn’t back track
- point and click navigation
- doesn’t tire and is tenacious

## Sub-Goal

**Sub-Goal**
- Search page
- recall early structural information from pre-load time
- LOOP for all structures on the page view
- 	identify structural area #1
- 	add to current page structures
- 	identify structural area #2
- 	add to current page structures
- 	compare 2 structural areas and select structural area to
- 	  eliminate or look at more closely
- 		LOOP - until all controls in structure are considered
- 		or user jumps out
- 		1st candidate:
- 			determine what kind of element
- 				interpret type of element
- 				compare new element to target
- 					if element is link,
- 					quickly compare link with target ....

## Accessibility

- Getting to a specific target
- Accomplishing a task
- Evaluating the path(s) experience(s)
- Evaluating selected, sampled or all targets
- Reporting a single metric

## Web Sites

**Web Sites**

**Web site **
**modeling**
**abstraction**
**and sampling**

**Instantiation of a standard web site user**

**Max web site use **
**behavior model**

**Max engine: **
**instructions to Max**

**Max’s experience**
**(Metrics and findings)**

## Strategy

- Determine significance of accessibility
- Determine if accessibility is observable, measurable, differentiable
- Correlate actual user data with subjective accessibility
- Compare Max accessibility metric to user data

##  Method

** ****Method**
- Subjects
-  Thirty (30) subjects
-  Ages 20-30
-  Web experienced (at least 1 year)
-  Tasks
-  6 information tasks
-  Same information on 2 or 3 web sites
- (e.g.,"the company's guarantee on its products" for REI, LLBean, and SierraDesign)
-  Randomized block design total of 15 tasks
-  Constraints on subjects
-  Home page and the target information
-  Point and click navigation
-  5-minute time limit

##  User testing data collected

** ****User testing data collected**
-  Clicks per view
-  Scrolling
-  Click offs before page load completion
-  Time from start to end of task
-  Path followed
-  Load times
-  Choice times
-  Subjective ratings of “accessibility”
- - Highly accessible
- - As accessible as information on the average web site
- - Less accessible than information on the average web site
- - Least accessible or inaccessible

## Differentiability

- Critical for metric validity
- For each task, statistically significant differences were detected for the time to find the task information between competitive web sites (p < 0.05 in all comparisons but one).
- Table 1 in the paper contains the details

## Time per task vs. subjective "accessibility" rating

**Time per task vs. subjective "accessibility" rating**
**A strong correlation was found (z[15] = 5.0, p < 0.0001)**

## User’s average time vs. WebCriteria Accessibility Value.  

**User’s average time vs. WebCriteria Accessibility Value.**
- Note:  The Accessibility Value is available for 13 out of the 15 tasks.

## Paired comparisons of relative orders of 

- Task 1	llbean vs. rei		 NO
- Task 1	llbean vs. sierra-design	YES
- Task 1	rei vs. sierra design	YES
- Task 2	llbean vs. rei		  ?
- Task 2	llbean vs. sierra-design	YES *
- Task 2	rei vs. sierra design	YES
- Task 3	honda vs. toyota	YES
- Task 4	toyota vs. chrysler	  ?
- Task 5	dell vs. compaq		YES
- Task 5	dell vs. apple		YES
- Task 5	compaq vs. apple	YES
- Task 6	dell vs. apple		 NO

**Paired comparisons of relative orders of **
**average user time versus Accessibility Values**

## Conclusions

- Accessibility is measurable, differentiable, and correlated with time
- Time to target user behavior can be modeled (whole web site characterized)
- Max accessibility value tracks rather well with the real user data
- There is much more work to do, but this is very promising