Garbage In Garbage Out is a design principle based on the the notion of bad input producing bad output and vice versa. If the end user has the ability to input any type of value with any given quality into a space without ways of preventing “invalid” inputs, the outputs will probably be equivalent to the input’s caliber. In the Universal Principles of Design book, the authors bring up two types of input problems: input type and input quality. Input type is focused more on inserting the wrong information into a space. An example of this might be entering your username in the password field on a login form. On the other hand, input quality is centered around injecting a flawed value that is of the correct type. For example, missing one number from your credit card number will result in a faulty transaction. There are ways to prevent garbage ins broken out by each kind of problem. Using affordances and constraints for input type issues and previews and confirmations for input quality issues will help minimize the impact of the input has on the output. Prevention of input error is the key to a successful interaction resulting in the expected and desired outcome.
Example #1: Order Forms
The image displays the preventative measures added in the redesigned form to avoid any potential garbage input values.
Example #2: Remote Controls
This example shows the many possible inputs or sets of inputs for an end user of remote controls. One might keep hitting the “1” button numerous times with the result not having to do anything with the number “1”. It might take the user to the “On Demand” channel or “Guide”. The lack of constraints allows for bad inputs.
Example #3: Cuisinart Coffee Maker
This example I struggled with this morning while house sitting my friend’s house. I wanted to make a cup of coffee and I was confident I set everything up correctly. When it came to the moment of turning it on, I was puzzled by how it worked. I turned the distinct “Ready Tone” knob to “ON” and nothing was happening. No coffee. I realized later that I had missed the “ON/OFF” button at the top since the color blended in with the rest of the machine and did not stand out to me. The main issue is the counts of “ON” on that machine: “Auto ON”, “ON”, and “ON/OFF”. The probability that a user will interpret only one of these “ON” labels to be true decreases as the number of “ON” options increases.
Resources:
Lidwell, William, Kritina Holden, Jill Butler, and Kimberly Elam. Universal Principles of Design: 125 Ways to Enhance Usability, Influence Perception, Increase Appeal, Make Better Design Decisions, and Teach Through Design. Beverly, Mass: Rockport Publishers, 2010. Print.
Wilkinson, Darryl, and Grant Clauser. “The Best Universal Remote Control.” Engadget, 24 Jan. 2017, www.engadget.com/2016/04/29/the-best-universal-remote-control/.
In our daily life, we encounter many of these types of poor design and it reminds me of our human anatomy system (this is the therapist that I am also wearing which leads me to this self-reflection). When we think about the preventative measures (e.g., additional cues on the order form), we design these based on the assumption that human do make mistakes when dealing with complex and lengthy information (e.g., our minds works best when we “chunk” information), therefore, we need to design to assist people’s direct user experience with the fundamental understanding of cognitive psychology about human mind.