Learn about various design methodologies and see how they are used in practice.

Key Methodologies of UI and UX Design

A collage of various flow charts, cycle diagrams, journey maps, honeycomb structures, and design-related interfaces and tools.

If you've started researching UI and UX design, you've likely seen terms like _design thinking_, _user-centered design_, and _double diamond_ floating around. But what do these terms actually mean? In this lesson, we will discuss various design methodologies and show how they are used in practice.

Design methodologies may seem convoluted and complicated at first. Not to worry&mdash;the purpose of these methodologies is to document learnings from years of research and work by others to make your job easier. Today's designers can choose between a wide variety of methods for any given project. Getting to know some of the key methodologies will help us understand how designers approach problems and tackle solutions.

UI and UX methodologies offer structure and consistency to focus on problems and drive success within a design process. Methodologies help get people on the same page, whether it's within a project, an organization, or an industry.

Over the years, organizations like [Ideo](https://designthinking.ideo.com/), [Google](https://design.google/resources/), and the [Nielsen Norman Group](https://www.nngroup.com), as well as people like [Peter Morville](https://en.wikipedia.org/wiki/Peter_Morville), have defined some of the most popular methodologies for executing and assessing UI and UX design, which we'll cover in this lesson.

Design theory and practice are constantly evolving. New methodologies and principles are defined constantly within design&mdash;for example, [design justice](https://designjustice.org/) and Microsoft's [inclusive design](https://www.microsoft.com/design/inclusive/) emphasize diversity, equity, and inclusion. 

There is no "right" methodology for any given scenario, and some situations may pull from multiple methods. Maybe one day, you'll even document and share your own methodology to change the way designers work!

Introduction to UI and UX Methodologies

A diagram of the five phases of the design thinking process: Empathize, Define, Ideate, Prototype, and Test.

The term _wicked problems_ was coined by design theorist Horst Rittel to describe the types of extremely complex, multi-dimensional problems that designers are often tasked to solve. Design thinking isn't limited to creating new products&mdash;it can affect change at a systemic level.

_Design thinking_ as a formal methodology has [developed across multiple disciplines since the 1960s](https://www.interaction-design.org/literature/article/design-thinking-get-a-quick-overview-of-the-history), and is commonly associated with the design and consulting firm [IDEO](https://designthinking.ideo.com/) and the Stanford School of Design (the [d.school](https://dschool.stanford.edu/)). 

Design thinking puts people at the center of every process and encourages designers to set aside assumptions. For example, instead of designing a new children's toothbrush, a design thinking approach would define "how to clean teeth" as the problem and explore a wide range of solutions. 

Like the double diamond model, design thinking offers opportunities to focus on both divergent and convergent thinking across its steps to encourage both creativity and problem solving. Design thinking lives at the intersection of desirability (people), viability (business), and feasibility (technology).

![A Venn Diagram illustrating the intersection of Desirability, Viability, and Feasibility.](https://static-assets.codecademy.com/Courses/intro-to-ui-and-ux/key-methodologies/design-thinking.svg)

Design thinking's core activities are inspiration, ideation, and implementation, which occur across the five stages of the process:
1. **Empathize**: Understand the user and the landscape.
2. **Define**: Define the problem and align with business goals and user needs.
3. **Ideate**: Generate a range of ideas for possible solutions, emphasizing creativity.
4. **Prototype**: Explore potential solutions by creating prototypes of the product to gather feedback.
5. **Test**: Test the best solutions developed during prototyping. Prototyping or testing may lead to redefining the problem altogether. As with the other processes we've covered, this is an iterative cycle.

Design Thinking

Illustrations of three tools used by user researchers to communicate their research findings: personas, storyboards, and journey maps.

We've spent a lot of time in this lesson walking through different design methodologies and emphasizing the role of the user in these processes. Where does this information about users come from?

_User research_ is the systematic study of target users of a product or interface to understand their behaviors, needs, and motivations. This is a broad field of its own, and in some organizations, a separate user researcher primarily focuses on this work. In addition, every UX or UI designer is likely conducting some user research. User research can happen at every stage of the design process to inform decisions.

Some researchers specialize in _quantitative research_ methods that can be measured numerically, such as surveys, analytics, and A/B testing. Others specialize in _qualitative research_ methods that examine why users behave the way they do in depth, such as interviews, focus groups, and ethnography.

Anthropologist [Margaret Mead](https://en.wikipedia.org/wiki/Margaret_Mead) once said, “What people say, what people do, and what people say they do are entirely different things.” User researchers need to develop strong interpretive and creative skills to get to the core of why people behave the way they do. It's important to combine multiple research methods for a full understanding of user behavior:
* _Attitudinal methods_ focus on what users say, through user interviews, surveys, and diary studies. 
* _Behavioral methods_ observe user behavior, through ethnographic studies, A/B testing, and user testing.

While _user research_, such as interviews and surveys, is done as part of the discovery process to get to know users better, *evaluation methods* like user testing and A/B testing assess how a design or prototype performs once it's complete.

A skilled user researcher is able to tell stories and frame their research in digestible ways that are useful and compelling for others within the organization. Tools like _[personas](https://www.codecademy.com/article/ui-design-personas)_, _[user journey maps](https://www.nngroup.com/articles/journey-mapping-101/)_, and _[storyboards](https://www.nngroup.com/articles/storyboards-visualize-ideas/)_ can be used to advocate for the user and circulate key points from user research across an organization.

Introduction to UX Research

A cycle diagram of the user-centered design process, with people at the center of the diagram. The four steps of the cycle are Understand, Specify, Design, and Evaluate.

_User-centered design_ (UCD) puts users at the center of product development and involves them in the design from the beginning. Here, design is seen as an iterative process that incorporates user feedback both during the development process and after launch. User-centered design responds to both contexts of use (such as the user's environment, technology, and emotional state) and business goals.

If this is beginning to sound familiar, you're right! UX and UI design as disciplines are user-centered, and associated methodologies generally fall under the umbrella of user-centered design. There are many parallels between the methodologies we've explored in this lesson, and any one of them will help us balance priorities and collaborate better as a designer.

While user-centered design processes may define the steps differently, they generally involve the following activities:
1. **Understand**: Empathize with the user.
2. **Specify**: Hone in on a specific problem to solve.
3. **Design**: Brainstorm and develop solutions.
4. **Evaluate**: Test the product or prototypes to assess success and incorporate feedback.

User-Centered Design

An illustrated list of Jakob Nielsen's ten usability heuristics.

Jakob Nielsen, co-founder of the [Nielsen Norman Group](https://www.nngroup.com/), devised a set of _ten usability heuristics_ as a set of general principles for good interaction design. 

Like the principles for good user experience described in the last exercise, these heuristics are intended as rules of thumb. They help designers assess where a design is excelling and falling short, and what trade-offs are being made in a design process.

Take a look at the [full list of the ten heuristics](https://www.nngroup.com/articles/ten-usability-heuristics/) on the Nielsen Norman Group's website. Here are some to highlight:
* **Visibility of system status**: The design should always keep users informed about what is going on, through appropriate feedback within a reasonable amount of time.
* **Consistency and standards**: Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform and industry conventions.
* **Flexibility and efficiency of use**: Shortcuts, hidden from novice users, may speed up the interaction for the expert user such that the design can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.
* **Help users recognize, diagnose, and recover from errors**: Error messages should be expressed in plain language (no error codes), precisely indicate the problem, and constructively suggest a solution.

The _[heuristic evaluation](https://www.nngroup.com/articles/how-to-conduct-a-heuristic-evaluation/)_ is a relatively quick and flexible method of usability testing, compared to other methods such as user testing. During this process, a group of expert evaluators classifies usability problems based on the ten heuristics. Heuristic evaluation is highly based on the evaluators' expertise and is not a replacement for testing a product with real users.

Nielsen's heuristics have inspired others to create alternate heuristics for assessment within different fields, such as [humane design](https://designlab.com/blog/heuristics-humane-design-designing-for-dignity/) and [persuasive health technologies](https://terpconnect.umd.edu/~choe/download/IHI-10-Kientz.pdf).

The 10 Usability Heuristics

An illustration of Peter Morville's UX Honeycomb diagram, with seven adjectives within each hexagon: usable, useful, desirable, valuable, findable, credible, and accessible.

The methodologies we've described so far ensure that teams are aligned and that user needs are at the center of the process, but what defines a "good" user experience? What makes a product or design truly great?

Numerous attempts to answer this question help make design critique less subjective. Designer and information architect Peter Morville's _[UX honeycomb](https://semanticstudios.com/user_experience_design/)_, pictured to the right, is one example of a framework for understanding the many facets of a positive user experience:
* **Useful**: fulfills a user's needs
* **Usable**: easy to use and understand
* **Desirable**: visually attractive and succinct
* **Findable**: easy to navigate and find information
* **Accessible**: users with disabilities can use the product
* **Credible**: the product, company, and services are trustworthy
* **Valuable**: delivers business value

Google takes a condensed approach to defining the [characteristics of a good user experience](https://bootcamp.uxdesign.cc/characteristics-of-a-good-ux-according-to-google-90bacda2abbb):
* **Usable**: easy to find and use functionality
* **Equitable**: benefiting individuals across skills and backgrounds
* **Enjoyable**: pleasing to use beyond basic functionality
* **Useful**: solves a user need

The distinction between descriptors like these is helpful when assessing a product or design. For example, a usable and desirable design may not be useful or answer a user's needs. A visually desirable design may not be usable or findable if it obscures important information or functionality. Any product that doesn't consider accessibility and equity may (whether intentionally or not) exclude a portion of the population who would otherwise find it useful.

For more resources on accessibility and designing for equity and inclusion, we recommend:
* [Codecademy: What is Digital Accessibility?](https://www.codecademy.com/content-items/c2b65f9281fdeff54c3a228926ed913c?preview=true)
* [W3C: Web Content Accessibility Guidelines](https://www.w3.org/WAI/standards-guidelines/wcag/)
* [The A11Y Project](https://www.a11yproject.com/)
* [Microsoft: Inclusive Design](https://www.microsoft.com/design/inclusive/)
* [The Design Justice Network](https://designjustice.org/)

Defining "Good" UX

A cycle diagram representing the five stages of the Product Development Life Cycle: Brainstorm, Define, Design, Test, Launch.

Design doesn't exist in a vacuum. Today's UI and UX designers don't just think about visual design: they are problem solvers involved in every stage of the product development process. The Product Development Life Cycle helps us understand how design fits into product development.

The _Product Development Life Cycle_ (PDLC) is a cross-functional, iterative process, usually involving many stakeholders across an organization. The process starts from a problem or pain point to ensure that product development meets a real user need and that the whole team is aligned around the same goals.

Often, a product manager owns this process at a high level. UX designers and researchers can be involved at any stage of the cycle to ensure user needs are taken into account. UI designers are responsible for the visual layer of the product, one of the many outputs of the process.

UI and UX designers can use the stated goals and definitions from the Product Development Life Cycle to ensure their work meets the captured requirements and to facilitate smooth collaboration with other stakeholders.

The Product Development Life Cycle consists of 5 stages:

1. **Brainstorm**: Starting from a defined problem or pain point, the team brainstorms all possible solutions. Market or user research can help inspire ideas.
2. **Define**: The team aligns on specifications for the product by defining the vision, goals, target users, features, benefits, and success metrics.
3. **Design**: The product is designed from low-fidelity to high-fidelity, starting with sketches and wireframes and moving to prototypes and a completed interface.
4. **Test**: The product or prototype is tested to ensure it works as intended. Testing can range from informal internal testing of low-fidelity prototypes to usability testing of a high-fidelity prototype or final product by external users.
5. **Launch**: The final design is released to the public, but the cycle doesn't end here. Typically, testing continues even after the product has launched, and the cycle continues.

The Product Development Life Cycle

That's a wrap! We got a walkthrough of foundational design methodologies and best practices, with an understanding of the key principles underpinning UI and UX design. Even as methodologies go in and out of vogue, core concepts, such as putting users at the center of design and iterating according to feedback, will never go out of style.

Here's a summary of what we've covered:
* *UI and UX methodologies* offer structure and consistency to focus on problems, drive execution, and define success within a design process.
* The *double diamond model* illustrates two modes of thinking that occur during the strategy and execution stages of the design process. The four phases of the double diamond process are: discover, define, develop, and deliver.
* _Divergent thinking_ explores many possible solutions and generates novel ideas, and _convergent thinking_ analyzes, filters, and focuses ideas to make decisions.
* The *product development life cycle* (PDLC) is a cross-functional, iterative process that can be viewed as 5 stages: brainstorm, define, design, test, and launch.
* *Design thinking* puts people at the center of every process and encourages designers to set aside assumptions to solve complex, multi-dimensional _wicked problems_. The five stages of the design thinking process are: empathize, define, ideate, prototype, test, across three core activities: ideation, inspiration, and implementation.
* *User-centered design* (UCD) is an iterative process that puts users at the center of product development and involves them in the design from the beginning. User-centered design processes generally involve the following activities: understand, specify, design, evaluate.
* The *UX Honeycomb* diagram defines "good" UX design as useful, usable, desirable, findable, accessible, credible, and valuable.
* The *ten usability heuristics* are a set of ten general principles for good interaction design.
* *User research* is the systematic study of target users of a product or interface to understand their behaviors, needs, and motivations. User research can happen at every stage of the design process to inform decisions. 
* Methods of user research include _quantitative user research_, _qualitative user research_, _attitudinal research_, _behavioral research_, and _usability testing_.

Next, we'll be exploring the career landscape of UI and UX design jobs!

Review

A single product can't solve every problem, and a single team can't develop every possible solution to a given problem. Design methodologies help teams focus and commit. 

The _double diamond_ is a broadly applicable process model for a cross-functional, iterative design or innovation process. This methodology was [formalized by the British Design Council](https://www.designcouncil.org.uk/our-work/news-opinion/double-diamond-universally-accepted-depiction-design-process/) in 2005 through an in-depth study of 11 global brands, including LEGO, Microsoft, Sony, and Starbucks. 

Take a look at the diagram to the right. The two-diamond structure of the diagram illustrates two modes of thinking that occur during the strategy and execution stages of the design process. _Divergent thinking_ explores many possible solutions and generates novel ideas. _Convergent thinking_ analyzes, filters, and focuses ideas and leads to decisions. 

This model promotes creativity and innovation while making it clear when decisions should be made and when teams should commit to a direction. A well-executed double diamond process ensures that product requirements and subsequent design work are focused on user needs.

The four phases of the double diamond process are as follows:

1. **Discover** (divergent strategy): Explore the problem and landscape, and learn from users and the market through user interviews, surveys, and other research.
2. **Define** (convergent strategy): Sort and analyze the information gathered during the discovery stage and hone in on the problem we're trying to solve. 
3. **Develop** (divergent execution): Generate a range of ideas for possible solutions through brainstorms, workshops, low fidelity prototypes, and other ideation methods. Test different ideas with users or within the company to see what resonates. 
4. **Deliver** (convergent execution): Hone in on, develop, and deliver the solution. Continue evaluating and testing the developed design to ensure it meets user needs.

The Double Diamond diagram: two diamonds side-by-side, broken down into Strategy (Discover and Define) and Execution (Develop and Deliver) phases, moving from problem to solution.