Home > Articles > Programming

The More Things Change: Lessons in User Centered Design

How does change affect a product’s user interface? This article discusses User Centered Design (UCD) as a best practice approach, not only in software user interface development, but also in evaluating change. The author explores some facets of change and the consequent impacts on a product’s user interface.
Like this article? We recommend

Change is a fact of life, and even more so in software and User Centered Design and development efforts. Natural sources of change during product development result from the following:

  • Evolution of requirements and business needs

  • Design changes based upon user and sponsor feedback

  • Design evolution due to "leaping eurekas" and opportunistic insights

Areas like the user experience are not immune to requirements change in other facets of a software application or system. For example, a change in a functional feature that is visible to users in some fashion has a corresponding change in user interface appearance, behavior, or user interaction. The usability of an application or system may or may not be impacted by such changes.

We'll explore some facets of change and the consequent impacts on a product's user interface. We'll also discuss User Centered Design (UCD) as a best practice approach not only in software user interface development, but also in evaluating change (see Figure 1). Some social aspects of change on a UC Product Team will be explored. An address book application that integrates with other applications is used as an example.

Figure 1 A user-centered process.

Dimensions and Components of Change

Product development balances components of an equation that include cost, schedule, and function. Change can take place in any of these areas—for example:

  • Features can be added, deleted, modified, or scheduled differently.

  • Cost of development can be reduced (it's usually not increased without duress).

  • Quality requirements can be made more stringent.

Let's consider another view of the equation that balances features, cost, and quality. The interaction between these components is depicted in Figure 2. The interaction between components is complex but somewhat intuitive. There are multiple factors that influence each component. A better visualization is Figure 3, which depicts the major components on three-dimensional planes, with subcomponents overlaid onto the appropriate plane. We'll now explore each major factor in more detail.

Figure 2 A balance of features, quality, and cost.


A broader look at the user experience and what a user can do with a system or application is a feature. There are multiple classes of features in a product; for example, function, data, user interface, etc. Changes to these features happen quite frequently during projects.

Figure 3 Feature dimensions.


User visible features include application domain and operating system functionality. Application functions form the core of what a user can do with software and serve its purpose. This is what a user can do with a product.


An example of application functionality is "create an entry in a personal address book," whereas an example of operating system functionality is "remove a personal address book application" from a system.

There are many functions common to all applications (for example, New, Open, Save, Print, and Help). There are many functions unique to each application (for example, New Person, Add Person to Distribution List, and Schedule a Meeting with a Group).


Related to functionality are features associated with application data. Some applications have more data features than other applications in the same domain.


A field for collecting and displaying a phone number is an example of application data. Other possible data features for an application include fields for collection and classification of more than one phone number; for example, Office, Home, Mobile, as well as Day or Night.

Data features are typically seen via the user interface controls used in views of objects (for example, entry fields and dropdown lists). A detailed view of a Person listed in an Address Book potentially has lots of data and controls. Data features are also made available to a user in command dialogs like New Person.

Data features also include ranges of accepted use; for example, lower and upper limits of acceptable data for a given field, corresponding formatting approach and flexibility, validation rules, and business rules. For example, a phone number may support a strictly numeric value or an alphanumeric value. A data feature as simple as a phone number becomes surprisingly complex if a product supports international phone numbers.

User Interface

User Interface features are the mechanisms for appearance, behavior, and user interaction with functions, data, and information. Appearance deals with static and dynamic visual and audible communication of information to a user in one or more views. Behavior deals with static and dynamic responses to user and other system interactions. User interaction deals with how a user communicates with an application via UI features such as menus, buttons, drag and drop, shortcuts, gestures, utterances, etc.


A user can print an entry in the address book via a menu command or by drag/drop to a printer.

Features of an application UI include a conceptual model, access methods, screen flow, objects, views, commands, feedback, and UI mechanisms.


Features related to information provided to users to explain an application and how to use it include instructions, help, interactive tutorials, wizards, tooltips, and performance support.


A user can request help on how to convert an address book group to a distribution list.


Features related to integration include those that facilitate exchange of data and/or interoperability between objects, applications, and the supporting desktop. Integration includes intra-object and inter-object operations. Other integration facilities include exploitation of system-level features such as shortcut keys and clipboard operations on entry field content.


Adding a person from an address book into a distribution list via drag and drop is intra-object, whereas dragging a person into a calendar is inter-object.


Developing a product with certain features at a desired level of quality is going to cost something. Cost factors are depicted in Figure 4. For a constant set of features, the cost of a product will vary based upon desired quality. For a constant cost, the implementable features and quality of a product may vary. Let's explore the dimensions of cost.

Figure 4 Dimensions of cost.


People are the most critical and expensive component of a project. People must work together smoothly and effectively in order to achieve desired results. Dimensions associated with people include roles, experience, attitudes, hourly cost, burden rates for the cost of overhead and benefits, travel, and other expenses.


People must have the right skills to tackle a project. If the skills are not available at project startup, the skills must be learned, internalized, and applied. Certain skills and learning times have higher costs associated with them.


Beyond people, the most productive, usable, and cost-effective development tools must be secured for project tasks. Some tools are moderately priced, whereas others are quite expensive. Some are easy to acquire, whereas others require time and effort to secure. Some are easy to use, and some are painful to use.


Along with tools, facilities such as office space, development labs, hardware, telephone and LAN lines, networks, software, and other materials must be secured for the project team. As with tools, facilities must be productive, usable, and cost-effective.


Along with people, doing the right things the right way is essential. Doing the right things in the most productive, usable, and cost-effective manner is essential. Some processes are better than others, given other cost factors relative to a set of features and quality goals.


The quality of a product has many dimensions. Quality varies, based on the features of a product and the cost of developing it. For example, missing features or poor user interface negatively impact a product's usability. By the same token, very stringent quality factors influence how many features are developed and how much is spent.

Rule of Thumb

Usually, you get out what you put in.

Figure 5 Dimensions of quality.


Not usually thought of as a quality factor, schedule is certainly a dominant aspect of most projects. If a project's schedule is too short, it can have impacts on other Quality factors, as well as Features and Cost. If a planned schedule is too long (which is not very often), other Quality, Feature, and Cost factors can be influenced. Alternatively, schedules are pressured due to voluminous project Features and constrained Costs. Perhaps Schedule should be its own axis in a four-dimensional coordinate system.


Response time is the dominant factor of performance, though throughput is sometimes important. A difficult aspect of performance is the challenge of predicting likely response times while in design. The more stringent the performance requirement, the higher the cost.


As with performance, it is difficult to predict the reliability of a system while in design and build. The first hints of stability do not surface until beyond unit test. As with performance, costs are higher with more stringent requirements.


Ease of maintenance is desirable for any product because the developers of a system are not likely to perform in maintenance roles after deployment. Maintenance costs are certainly higher with systems that have been thrown together quickly with insufficient design materials.


Time to learn, productivity, error-free use, and user satisfaction are measures of usability. The higher the level of Features, the more pressure is placed on UI and usability factors. The lower the Cost in support of UI and usability, for example, engineering skills of the development team, the more pressure is placed on product usability. The more stringent the requirements for usability, the higher the Cost.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020