According to William Lidwell, author of Universal Principles of Design and The Science of Logo Design, a good logo will stimulate 4 cognitive events. It should:
- grab attention,
- elicit an emotional response,
- express multiple intentional meanings,
- and be memorable.
Of the four cognitive events, the third—express multiple intentional meanings—is the first to tap into conscious thought. The science and/or math behind expressing multiple intentional meanings is called propositional density.
The key to achieving propositional density is selecting an image that incorporates multiple favorable meanings with the fewest possible design elements.
Of course, this naturally lends toward producing a simple image rather than a detailed one.
Looking Back at the History of Logos
Lidwell claims that some very popular logos are not good, even though the brand and the products aligned with them have been successful in the worldwide market.
One of the reasons this could be true is that modern marketing has adopted the use of psychological principles, as Kimberly Elam suggests in the forward of Lidwell’s Universal Principles of Design. Logos designed before the dawn of modern technology and communication generally do not have the same appeal as good logos have today, which Lidwell argues in the final chapter of the Lynda.com course, The Science of Logo Design.
So today’s good logo design is not solely based on good graphic design; it’s also based on psychology which heightens our interaction with a logo based on what we bring to it consciously and subconsciously.
At most, it might be characterized as a re-prioritization of mind-handling ability over precise graphic design skills—or in the least, putting them on equal footing.
Putting Knowledge to Practice
While processing these concepts, I applied them in analyzing the first two logos that I designed. The logos were created after I completed Before and After: Logo Design Tips and Tricks. Impulsively, I studied the how and got to work before I studied the why.
The first logo was composed of stylized words (the name of a business) and the second was composed of an image on which I applied branding standards from an existing brand.

The first logo (above) is satisfactory based on Lidwell’s four cognitive events and it is properly aligned to the desired brand identity. It was adopted and it’s in use.
The second logo (below) is satisfactory on the four cognitive events and its alignment to an existing brand, but it was not put into use because the chosen image did not accurately reflect the desired perception of the product. It was related, but it was not exact.

What makes a logo designer good?
One insightful thing I gleaned from my design experiments and more recently, Lidwell’s instruction, was how important it is for a designer to communicate precisely and directly with someone who commissions logo creation.
As a result, I came up with the idea to create a questionnaire that would help me get pertinent information and preferences from a client in one sitting. When it’s finished, the questionnaire will save time, energy, and money. Hopefully, it also makes the brand development experience uniquely positive for both parties.
It’s easier to design a logo for oneself because there is not a need to externally communicate preferences to another party.
Further, a satisfactory logo designer is arguably a skilled graphics technician, while a great logo designer uses the requisite skills, applies psychology, and facilitates clients’ communication in order to satisfy their needs.