VCR Remote

Problem Description

My mother recently bought a new VCR. After a short period of setup and testing, everything appeared to be working properly. The next time I went to visit her, she asked me to fix the VCR. When I asked her what was wrong, she informed me that it never recorded anything. I tried to record something that was on at the time, and it worked perfectly.

HCI Analysis

I've never seen a VCR that wansn't an HCI nightmare. Here is a picture of the remote control for my VCR:

(Note: This remote isn't the same as the one my mother was using, but all of the features discussed in this diary entry are the same.)

Even at first glance, it is obvious that the remote is far too complex for novice or occasional users. Shneiderman (1992) discusses the need for novices to be given a constrained set of actions, with the allowance to access more features when the become expert users.

This remote features buttons labeled "POWER", "VCR1", "VCR2-LD", "TV", "TV-VCR", and "INPUT".

So which button should I use to turn the VCR on? A reasonable guess would be to use the "POWER" button. Another good guess would be to use the "VCR1" button. However, for the VCR to turn on, the "VCR1" button must be pressed to put the remote in VCR mode, and then the "POWER" button must be pressed to turn the VCR on. This operation violates Apple's (1992) principle of modelessness.

And once it's on, how can I actually make the tape record what I see on the TV screen? This operation depends not only on the mode of the remote, but also on the mode of the VCR. Either the VCR must be in "VCR" mode, with the TV on channel 3, or the TV and VCR must be set to the same channel. A very simple intention has translated into a highly complex action, making Norman's (1988) gulf of execution very difficult to bridge.

Even though my mother has owned many VCRs, and been able to use all of them, the new model utterly confused her. She had experience with the "TV-VCR" setting, and after a while, she became used to the modal nature of the remote, but this VCR added another mode. The tiny "INPUT" button controls an extremely important feature: whether the VCR takes its input from the TV antenna or one of the external inputs. Since my mother often makes copies of her home movies, she needs to use the external inputs frequently (and has detailed instructions for doing so). However, when she wants to accomplish a simple task such as recording the current program, she assumes her mental model of the system is correct, and doesn't consult the written instructions.

The overly-modal nature of this VCR illustrates Cooper's (1995) design principle "User interfaces that conform to implementation models are bad."

Recommendation

Over the years, I've observed many people who couldn't decipher the use of the TV-VCR button, but manufacturers continue to make remotes with these buttons. The "TV-VCR" button is really only necessary when the user wants to watch one program while taping another one. I would consider this to be advanced feature. In my experience, few poeple know how to do this, and even those that do understand it seldom find a need to use the feature. As such, the button should be hidden away from novices.

One way to improve a modal remote is to have mode lights, or a switch that is obviously in a particular position. This would allow the user some feedback, and help in creating a more accurate mental model.

Can we design a completely non-modal remote for multiple pieces of equipment? I think so, but that discussion is beyond the scope of this diary entry.

References

Apple Computer (1992) Macintosh Human Interface Guidlines. Addison Wesley. [Chapter 1]

Cooper, A. (1995) About Face: The Essentials of User Interface Design. IDG Books Worldwide.

Norman, D. (1988) The Psychology of Everyday Things. New York: Basic Books [Chapter 2]

Shneiderman, B. (1992) Designing the User Interface: Strategies for Effective Human-Computer Interaction. Addison-Wesley. [Chapter 1]

rscherle@cs.indiana.edu

Last modified: Fri Mar 26 16:24:19 EST 1999