EAC Decision on Request for Interpretation 2015-04

(Visual Display Characteristics; Minimal display area)

VVSG 1.1 Volume I, Section 3.2.5 a (v.)

Date: 

October 26, 2015

Questions:

What size display panel must a manufacturer use to meet the requirement for a minimum 

display area of 700 cm2? What is the nature of this requirement, and is it an absolute? 

Section of Guidelines:

3.2.5 Visual display characteristics 

The requirements of this section are designed to minimize perceptual difficulties for the voter. 

Some of these requirements are designed to assist voters with poor reading vision. These are 

voters who might have some difficulty in reading normal text, but are not typically classified as 

having a visual disability and thus might not be inclined to use the Acc-VS. 

a. If the voting system uses an electronic display screen as the primary visual interface 

for the voter, the display shall have the following characteristics: 

i. Flicker frequency NOT between 2 Hz and 55 Hz. 

ii. Minimum display brightness: 130 cd/m2

iii. Minimum display darkroom 7×7 checkerboard contrast: 150:1 

iv. Minimum display pixel pitch: 85 pixels/inch (0.3 mm/pixel) 

v. Minimum display area 700 cm2

vi. Antiglare screen surface that shows no distinct virtual image of a light source 

vii. Minimum uniform diffuse ambient contrast ratio for 500 lx luminance: 10:1 

Discussion:

At the time it was written (2006-2007) this requirement assumed a kiosk-based voting system 

and wanted to ensure that these products would use the minimum sized LCD monitors typically 

available at that time for legibility of the ballot and to permit enough information for the ballot 

displayed per screen. The requirement was intended to apply not just to electronic ballot 

displays, but also to the screen of precinct-based optical scanners that would provide feedback 

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to the voter before the scanned ballot was cast, to clearly indicate any overvotes, undervotes, 

and to provide an opportunity to verify the ballot before casting.

Display area is derived by multiplying the total pixel height and width. Therefore as an example, 

a 15” inch monitor with a 4:3 aspect ratio has a width of 30.48cm ( 1 inch = 2.54cm) and a 

height of 22.86cm, for a total area of 696.77cm2 (rounded to 697cm2

). Please note that for the 

purposes of this RFI, this area of 697cm2 will be deemed to meet the 700cm2 requirement. The 

attached table notes the display area of several common monitor sizes with both 4:3 and 5:4 

aspect ratios.

Exceptions: 

Although larger screens make the visual display easier to read and navigate, the 700cm2

requirement is somewhat arbitrary, in that it is dependent on the context of use, and so there 

may be cases where a smaller display is currently used and is acceptable as noted below. 

However, the usability and accessibility requirements still apply. If the minimum display area is 

smaller than 700 cm2

, the burden of proof of the usability and accessibility of a smaller display 

is on the manufacturer. This implies that the product has undergone thorough usability 

testing and the submitted usability test reports demonstrate good usability and accessibility 

performance (in particular, works for low literacy, low vision, and dexterity). In these cases, 

EAC will have the reports evaluated by usability/human factors experts to confirm the findings 

in the manufacturer submitted usability test report(s). 

Conclusion:

Current research indicates that it is both reasonable and desirable that a voting machine ballot 

display should meet the 700cm2 display area requirement contained in Section 3.2.5 (a) (v) of 

the VVSG 1.1. This includes precinct count optical scanners as well as ballot marking devices 

and DRE (or DRE-like) machine displays. From a practical aspect, it is clear that smaller displays 

may also provide acceptable usability and accessibility while allowing current products using 

such smaller displays to remain in the market as a cost-savings to both election officials and 

voting system manufacturers. For this reason, previously EAC certified display screens not 

meeting the 700cm2 requirement are grandfathered until further notice providing the 

manufacturer complies with the stipulation noted in the paragraph above and in the Effective 

Date notification of this document.

Effective Date: 

Effective immediately for all new voting systems. Visual display screens of previously certified 

systems are grandfathered until further notice, but when submitted for modification testing 

with components not meeting this requirement, must submit the appropriate usability test 

reports at the time of application.

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Diagonal 

(in)

Diagonal 

(cm)

5:4 

Aspect 

Ratio

Width

(cm)

5:4 

Aspect 

Ratio

Height

(cm)

5:4 

Aspect 

Ratio

Area

(cm)

4:3 

Aspect 

Ratio

Width

(cm)

4:3 

Aspect 

Ratio

Height

(cm)

4:3 Aspect 

Ratio

Area (cm)

11.6 29 23 18 423 24 18 417

13.3 34 26 21 557 27 20 548

14 36 28 22 617 28 21 607

15 38 30 24 708 30 23 697

15.4 39 31 24 746 31 23 734

17 43 34 27 910 35 26 895

Display Sizes of Select Monitors (width, height and area numbers 

rounded)

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