counter height and fingerprint scanner angle
DESCRIPTION
Mary Theofanos. Brian Stanton. Counter height and fingerprint scanner angle. A case study on the importance of experimental rigor. Human Computer Interaction 2 Views of the Same System. Engineering. Participant presents Attempt starts. System starts capture. Capture. Attempt. - PowerPoint PPT PresentationTRANSCRIPT
COUNTER HEIGHT AND FINGERPRINT SCANNER ANGLEA case study on the importance of experimental rigor
Mary Theofanos
Brian Stanton
Human Computer Interaction2 Views of the Same System
2
System starts capture
Capture
Capture thresholding
Time
Engineering
Capture repeated if unacceptable
Human Factors
Participant presentsAttempt starts
Next attempt(acceptable
attempt)
Attempt
Attempt ends
Why is experimental rigor so important in our program?
Test must be valid That we are really testing what we say
we are Results must be repeatable
Everything documented so someone else can replicate
Results must be generalizable We usually can’t test everyone so we
want to test a sample and generalize to a larger population
Our results are fielded quickly
Why is rigorous design necessary?
Think of it as taking noise out of the system
Experimental Design
Introduction Method
Participants Equipment Procedure
Results
What question does this study try to answer?
Introduction
Problem:
United States Visitor and Immigrant Status Indicator Technology (US-VISIT) transitioning to a 10-print process (new scanner)
Existing counters too tall for a 10 print Can’t change the existing counter heights ($)
US-VISIT needs: Throughput – process travelers as quickly as
possible Quality – collect best possible fingerprint
images Customer Service – concerned for travelers
comfort and safety
How about angling the scanner?
Given current surface heights, what is the “best” angle for a electronic fingerprint scanner?
Question:heights “best” angle
Heights
30 33 35 36 37.5
38 39 43 45 47 48 490
102030405060708090
100
Border Entry Counter Heights
Counter Height
Fre
qu
en
cy
Heights
Scanner Model at three heights 39” 45” Practical
Midpoint 49”
39”45”
49”
Angles
With CAD Software looked at a Range of Angles at the three Heights Example: 39”
Angles
Selected Range of Angles0°10 °20 °30 °
0° 10° 20° 30°
3 Heights and 4 Angles
Heights 39” 45” 49
Angels 0° 10 ° 20 ° 30 °
What to collect and how to collect it?
Method
Who does this study address?
The flying publicRepresentative of
What characteristics of the traveling public are important?
AgeHeightGenderAbility
Age
People between the ages of 14 – 79 are required to present prints when arriving in the US.
Height
Population Height
5th Percentile Female149.9 cm (59.0 in)
95th Percentile Male184.9 cm. (72.8 in.)50th Percentile
166.6 cm (65.6 in)
Gender
Equal mix male and female
Ability
Assumption: disabled travelers will have an alternative method.
Participants
Representative of the traveling public 14 -79 Years Even numbers of men and women Heights ranging from 150 cm. to 185 cm.
Participants’ Rights
Institutional Review Board…to review the ethical acceptability of all research conducted where human subjects are used…
To protect the physical and psychological well-being
of subjects
To serve as a safeguard to protect against errors in
ethical judgment
To assure human subject testing is in compliance
with Part 27 of Title 15 of the Code of Federal
Regulations
To protect the privacy of the participants
Scanners
Equipment
Two Electronic Fingerprint Scanners
Each was compliant with Department of Homeland Security’s requirements and was supplied to us. Capable of taking a 10 print 6” x 6” x 6”
Table
Equipment
Adjustable Table
Equipment
Scanner Angle
Equipment
Scanner Angle
Equipment
Now we know the heights and angles and all the equipment, how do we put them together?
Experimental Design
Between Variables and Within Variables
Between: Each participant is tested on one condition
Within: Each participant is tested on every condition (repeated measures)
It takes some analysis to know when and how to use them.
Between Participant Design
39” 0°
39”
10°
39”
20°
39”
30°
45” 0°
45”
10°
45”
20°
45”
30°
49” 0°
49”
10°
49”
20°
49”
30°
Height Angle
Within Participant Design
39” 0°
39”
10°
39”
20°
39”
30°
45” 0°
45”
10°
45”
20°
45”
30°
49” 0°
49”
10°
49”
20°
49”
30°
Height Angle
Mixed Design
Height Angle
Angle Angle AngleAngle
HeightAngle Angle AngleAngle
HeightAngle Angle AngleAngle
Experimental Design
4 Angles 3 Heights
3 x 4 mixed design
12 possible combinations
Each person gets a height and each angle
0° 10° 20° 30°
0° 10° 20° 30°
0° 10° 20° 30°
39”
45”
49”
Experimental Design
Since each person gets every angle, order of presentation was counterbalanced
Right/Left start Randomly Selected
0° 10° 20° 30°
0° 10° 20° 30°
0°
Right
Left
10°
Left
Right
20°
Right
Left
30°
Left
Right
39”
45”
49”
What do you collect and how?
Data Collection
What to measure?
Given current surface heights, what is the “best” angle?
Definition: ISO 13407:1999 “Usability: 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.”
What to measure?
Given current surface heights, what is the “best” angle?
Best = US-VISIT needs:
process travelers as quickly as possible Efficiency – : Timing – Time to complete task
collect best possible fingerprint images Effectiveness – : Quality – How good were the
prints concerned for travelers’ comfort and safety
Satisfaction –: Comfort - Questionnaire
effectivenessefficiency satisfaction
Timing
Opportunity (“please place your hand on the scanner”)
System starts capture
Capture
System ends capture (“Please remove hand from scanner”)
Capture thresholding
Time
System
Participant presentsAttempt starts
Attempt
Attempt ends
Next attempt(acceptable
attempt)
Participant
Data: How many participants?
12 prints/angle
Data
12 prints/angle
× 4 angles = 48 prints/height
Height0°
Right SequenceIndex
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
10°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
20°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
30°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
DataHeight
0°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
10°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
20°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
30°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
Height0°
Right SequenceIndex
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
10°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
20°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
30°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
Height0°
Right SequenceIndex
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
10°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
20°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
30°Right Sequence
Index
Middle
Ring
Little
Right Thumb
Left SequenceIndex
Middle
Ring
Little
Left Thumb
ThumbsRight Thumb
Left Thumb
× 4 angles = 48 prints/height
12 prints/angle
× 20 people (120 people total) = 960 prints per height
× 3 heights = 2,880 prints/scanner
× 2 scanners = 5,760 total prints
Demographics
Age Gender Handednes
s Right
Handed Left Handed
Ambidextrous
Height
Questionnaire
Which angle did you find most comfortable? 0 degrees 10 degrees 20 degrees 30 degrees
Which angle did you find least comfortable? 0 degrees 10 degrees 20 degrees 30 degrees
Please rank the following angles in order of preference by writing a 1, 2, 3 or 4 next to each angle. 1 is most preferred, 4 is least preferred. 0 degrees 10 degrees 20 degrees 30 degree
Detailed Protocol and Procedures Two teams
Two identical collection platforms Backups for each system and device Run throughs and dry runs Formal schedules Test scripts Explicit instructions and procedures Observation forms Completed the testing (120 participants in
2 weeks)
Above all be humble in the face of the data
Results
Efficiency: Task Time
Task Angle
Table Heigh
t
Participant
Height
Median Time
(s)
1 right slap
- - - 10.03
2 right thumb
- - - 10.53
3 left slap - - - 10.00
4 left thumb
- - - 10.01
5 both thumbs
- - - 10.03Task Angle
Table Heigh
t
Participant
Height
Median
Time (s)
1 right slap
- - + 16.83
2 right thumb
- - - 16.81
3 left slap - - + 16.87
4 left thumb
- + - 16.85
5 both thumbs
- - + 11.38
Scanner A
Scanner B
Significance for Time ("+" : p<0.05)
For each response variable of time we examined the factors of angle, table height, and participant height
We found: No significant effect due to angle on the time required to complete fingerprint task
Effectiveness: Fingerprint Quality Determining Fingerprint Quality of a slap
is controversial Performed the analysis 3 ways for
completeness No significant effect on Quality due to
Angle
User Satisfaction
Taller participants indicated that the 30° angle was least comfortable.
Shorter participants indicated that the flat angle was the least comfortable
Observational Data
Participant Performance Scanner Performance
DHS implementation based on our findings
Scanner in action
Our findings have implications
Start with right hand Use single thumb
Thumb rotation Grasping scanner
Angle scanner One scanner performed
better
Start with right hand Use single thumb Angle scanner Selected better
performing scanner
Our Experimental Findings
US-VISIT Field Recommendations
Thank you
100 Bureau Dr.Stop 8940Gaithersburg MD 20899
http://fingerprint.nist.gov/ Biometric Usability NISTIR 7504, Usability
Testing of Height and Angles of Ten-Print Fingerprint Capture