What is consistency in Norman's design principles?

In Norman's design principles, consistency is one of the critical pillars of user-centric experience that refers to maintaining uniformity and predictability across a system or interface. Let's delve into the significance of consistency in design and its impact on creating intuitive and engaging interactions, particularly in web and mobile design.

Importance of consistency

Consistency acts as a guide, lighting the way for users as they navigate complex digital environments. It makes things feel familiar, eases the mental effort needed, and gives users the power to predict and grasp how an interface functions. Whether it's about how things look or how they work, consistency creates a sense of order that seamlessly ties the user experience together.

Consistency manifests in two critical dimensions: aesthetic and functional.

1. Aesthetic consistency: Maintaining a cohesive visual identity across an interface. This includes consistently using the same color palette, typography, and design elements. Users feel a sense of continuity and brand recognition when they encounter familiar colors and typography, contributing to a unified user experience.

2. Functional consistency: Maintaining consistent behavior of interactive elements. Buttons, links, and navigation should perform the same actions across different pages. For example, if clicking the logo on a website's header takes users to the homepage, this action should remain consistent throughout the site.

Consistency in design elements

Let's look at some design elements where consistency is important.

Button placement and styling

A consistent design ensures that buttons for primary actions should have the same appearance and are located in a predictable place to help users find essential actions quickly.

The example above demonstrates the importance of button styling. The example on the left shows consistency in design by similarly applying rounded corners and drop shadows to the buttons. The example on the right has two buttons with different sizes, colored labels, and effects.

Iconography

Consistent use of icons helps users recognize their meanings easily. For example, a magnifying glass icon should consistently represent the search function. Here is an example of how consistent iconography can elevate the design.

The example on the left uses rounded stroke icons in white, while the design on the right uses the same iconography, but the style and colors are very different.

Navigation

Consistent navigation patterns help users understand how to move between different sections or pages. For instance, if a website uses a horizontal menu at the top for navigation, this should be consistent across all pages. If the website were to use the bottom navigation bar or a hamburger menu instead for some web pages, it would lead to a poor user experience.

Effect of consistency on users

Consistency influences the user experience, shaping how users perceive, navigate, and interact with a system or interface. Here's how consistency affects user experience:

• Familiarity and learning: Consistency creates a sense of familiarity. When users encounter consistent design elements and patterns, they feel more comfortable and confident in navigating the interface. This reduces the learning curve, as users can apply their knowledge from one part of the system to another.

• Reduced cognitive load: A consistent design requires less mental effort. Users don't need to figure out how different elements work or how to perform certain actions because they can rely on their previous experiences. This reduces cognitive load, allowing users to focus on their tasks without being bogged down by confusion.

• Predictability: Consistency enables users to predict the outcome of their actions. Users can anticipate what will happen next when interactions behave the same way across the interface. This predictability fosters a sense of control and confidence in using the system.

• Efficiency: A consistent interface accelerates user interactions. Users don't need to stop and think about how to perform each action or where to find specific elements. This efficiency leads to quicker task completion and a smoother overall experience.