Faces AD

Version 1.3a
28 March 1996

What is Faces?

Faces is a screensaver module for use with Berkeley Systems’ After Dark or any other screensaver that will run After Dark modules (such as Darkside of the Mac). It generates and displays random Chernoff faces. To use it with After Dark, just drop it into your “After Dark Files” folder and select it from within the After Dark control panel.

A new version of Faces is available for use with the built-in screensaver in Mac OS X

Where Can I Get Faces?

Faces is available for download at: or

So What’s a Chernoff Face, Anyway?

Chernoff faces are simplified, cartoon-like faces that can be used to graphically display complex multivariate data. They draw upon the human mind’s innate ability to recognize small differences in facial characteristics and to assimilate many facial characteristics at once. Each of several variables (up to 18) is assigned to a facial characteristic and a face is then generated for each condition. The method was developed by the Stanford statistician Herman Chernoff and presented in a 1973 paper in the Journal of the American Statistical Association titled The Use of Faces to Represent Points in k-Dimensional Space Graphically. If you want to know more about Chernoff faces, I encourage you to find this article. Although academic, it is quite readable by those without a background in statistics.

The faces drawn by the Faces module vary in just eleven characteristics, as shown below. In addition, depending on the current settings, the faces may also vary is size, location, and color. The face-generation routine is based on code by Dave Johnson in develop #6 (which is in turn based on Clifford Pickover’s Chernoff face routine in his book Computers, Pattern, Chaos, and Beauty).

"Annotated Face"

Interesting Tidbit

In the appendix to Chernoff’s 1973 article, he mentions:

“At this time the cost of drawing these faces is about 20 to 25 cents per face on the IBM 360-67 at Stanford University using the Calcomp Plotter. Most of this cost is in the computing, and I believe that it should be possible to reduce it considerably.”


Faces provides four controls for your customization pleasure. The first is a pop-up menu that allows you to select which style of drawing the module will use. In “Left Brain” mode, the faces are drawn in tidy rows and columns. In “Right Brain” mode, the faces are located on the screen(s) randomly.

The other three controls work more-or-less the same no matter which drawing style is used. It should come as no surprise that the “size” slider controls the size of faces that are drawn, or that the “speed” slider controls the time delay between faces. Setting the size slider to the far right will cause the Faces module to pick a size randomly. In Left Brain mode, this means a new size will be chosen each time a screen has been filled with faces. In Right Brain mode, the size of each individual face is chosen randomly. The last control is a checkbox that controls whether the faces are drawn in color (this control is absent on machines without Color QuickDraw).


Faces should work fine on any Old School Macintosh, including those with multiple monitors. It is fully compatible with the Randomizer and Multimodule features in After Dark. If you encounter problems with Faces, please let me know at the e-mail address below.

Recent Changes

1.3a (28 March 1996)

  • Added Register application to Faces distribution.

1.3 (18 September 1995)

  • Changed contact information in the info text and in this document; no other changes.

1.2 (16 May 1995)

  • Improved the method used to map the face size slider to a specific size while in “Left Brain” mode.
  • Fixed a nasty (but rare) divide-by-zero bug.
  • Added an improved “thumbnail” icon and animation. Improved the random-color code to avoid very dark colors that don’t show up well.

1.1 (14 May 1995)

  • Added “Left Brain” drawing mode (inspired by “Faces in the Dark,” by Geoff Hutchinson).
  • Slightly improved overall speed.
  • Added an additional face parameter (nose width).

1.0 (3 May 1995)

  • Initial public release.


Faces is now freeware. You may use Faces for as long as you want for free. You may distribute Faces in any way you wish as long as you don’t charge for it (not including normal connect-time download charges) and you distribute only the complete distribution, including documentation. You may not distribute this program on any disk costing more than $5 or on CD-ROM without my explicit permission.


Bradley D. Mohr disclaims all warranties relating to this software, whether express or implied, including without limitation any implied warranties of merchantability or fitness for a particular purpose. Bradley D. Mohr will not be liable for any special, incidental, consequential, indirect, or similar damages due to loss of data or any other reason, even if Bradley D. Mohr or an agent of his has been advised of the possibility of such damages. In no event shall Bradley D. Mohr be liable for any damages, regardless of the form of the claim. The person using the software bears all risk as to the quality and performance of the software. Because some states do not allow the exclusion or limitation of liability for consequential or incidental damages, the above limitations may not apply to you.


Faces 1.x is Copyright ©1995-1996 by Bradley D. Mohr. All rights reserved.

Contacting the Author

I always enjoy getting comments about Faces, whether good or bad. Send comments or suggestions to