The principle of Occam's Razor offers interaction designers three ways to keep complexity under control.

Occam's razor has been really useful to me on several projects recently. It's nothing new. Occam was around in the 14th Century. And it wasn't even his idea: it might well have been Aristotle's. Perhaps that long history proves that it's a great tool to have in your arsenal when designing user experiences.

The basic idea is something like:

"If you have two equivalent theories or explanations for observed facts, all other things being equal, use the simpler one."

The user-centred design version might be:

"If you have two interfaces that both address user needs, go with the simpler one."

But there are three different ways the idea gets expressed, and each form has something to offer interaction designers.

First blade: Choose simple solutions

"Two interfaces - choose the simpler one." A no-brainer, right? Simple designs are easier to implement and maintain, and quicker for everyone to learn and use. But choosing a simple design when you see it is actually surprisingly hard. Organisations with lots of people, objectives and agendas will generate complexity faster than you can say "knife" (or indeed "razor").

• Some stakeholders can be left feeling short-changed by simple designs that do what customers and users really want. One cry that's very familiar to website designers is "but I want my product/service/department promoted on the homepage too". And that leads to tragedy.
• Other stakeholders will obsess about edge-cases - things that logically can happen, but very rarely will. Catering for all of these ties your design up in knots.
• And some people seem to gain a sense of importance from fiddling with a good design - turning it, step by step, into a disastrous mess. This video about the design of the stop sign says it beautifully.

All these kinds of events will conspire to push an unwary interaction designer off course. Remembering Occam's razor, and quoting it to your clients, team and stakeholders, can help to keep you focussed and change other people's points of view.

Second blade: Keep merging features

Another common phrasing of Occam's razor is:

"Entities are not to be multiplied without necessity."

In interaction design terms I like to phrase it as:

"Whenever you see two things that seem to do something similar, see if you can turn them into just one thing."

"We've got the 'picker' over here, for choosing widgets from a long list in alphabetical order. And the 'chooser' which sits over there for choosing widgets from a categorised short list. Then there's the 'finder' up here which is for finding widgets which might be in either list. And the 'selector' over there which pops open when you need to select a widget from the full database."

You get the idea. If you find yourself having conversations like that you should take a breath, and realise that you've multiplied your entities beyond necessity. Chances are you need one tool for selecting widgets, not four.

For example, Google has taken the merge blade to their Chrome web browser. They've merged the search box and the URL box into one. Those are two very different boxes. But from most people's point of view having one box where you type in what you want is great. No tricky decisions to make.

So as you go along, be on the lookout for ways to merge multiple separate components in your design into one. You'll end up with a design containing a few flexible items, instead of many small, inflexible ones. Typically that means less to learn, and a more elegant user experience.

Third blade: Don't oversimplify

Knowing when something is simple enough can be tricky. Trying to oversimplify something that is inherently complex can be a waste of time. How do you know when to stop?

Einstein's phrasing of the rule helps us here:

"Make everything as simple as possible, but not simpler."

The UCD version is, perhaps:

"Understand what people really need to do and make sure that your simplest design really does all those things."

That's why UCD stresses that you need to go out and observe your target users in action. It's the only way to find out what they really need.

A single button mouse is a great example. Apple hung onto the idea for years, and with good reason. It really is way easier to learn than a two button mouse. Watch a young child using a two-button mouse and see how many errors they make by pressing the right button intead of the left. But in the end, the multibutton mouse has won. Why? For the applications people were running in the early nineties, one button was often sufficient. But people's needs and expectations have grown, and now a single button mouse can't provide convenient access to the wide range of features people expect, and know how to use. A two button mouse, plus scroll wheel, lets people do more of the things that they really want to do, more quickly.

But this does beg a question, though. With a complex piece of software like MS Word 2007, people want to do hundreds of different things. How can you ever make something like that simple?

Alan Kay to the rescue:

"Make simple things easy and difficult things possible."

In other words make sure that you prioritise your design. Put the most commonly used features within easy reach and tuck away the more specialised and advanced ones.

The deadline sharpens the blades

It's easy to get tangled up. What MUST users have? What would they like a lot? What do we think they should want? Can we just squeeze this element in? What would happen if they tried to do that other thing? Luckily, Occam's razor suddenly gains power when you are faced with looming deadlines and limited resources. Those force you to really use the razor and they have the power to silence the most tangled corporate debates.

And when you're forced to use it, something amazing happens. All the "what about if" cases drop away, leaving you with the "all users will want to" cases. And following close behind that you typically find a clean, simple interface. Simple because it doesn't have to solve all the world's problems, just a manageable and intelligible subset.

So:

• Quote Occam's razor to help you fight for simple interfaces when you see them
• Look for interface elements which you can merge into a single element
• Understand what target users are really trying to do, so that you know exactly how complex things have to be
• Prioritise features so that the most popular are visible and the advanced ones are tucked away
• Use the power of the deadline to force yourself or your team to stop adding complexity and start fighting your way towards simplicty.

And remember Antoine de Saint-Exupery, author of "The Little Prince":

"A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away."

Flow, together with Splendid, designed Jamie Oliver's new Jme lifestyle collection website. It was a classic user experience challenge, but this one went further. We soon discovered that the best approach was to integrate the shop with Jamie's already active community site.

Understanding the fans

Jamie Oliver fans like relaxed living and eating with an edge of no-nonsense practicality. They care about the environment they live in and about supporting people who make the food and products they love.

What does that mean for online shopping? We created a hypothesis. Jamie Oliver fans would want:

• Inspiration: How to mix and match products, recipes and ideas so they can live the Jamie lifestyle
• Usefulness: Understanding how products would fit into their lives and help them achieve their goals (a great dinner party, a beautiful home, and flourishing garden...)
• Background and context: Insight into where the products come from, who designs and makes them and why they are special
• Connectedness: Helping customers to form a connection to the community, the product designer and Jamie.

When we considered this, we realised that the Jme site should be integrated with JamieOliver.com, Jamie Oliver's existing blog and community site. Inspiration might come from seeing a photo of a family gathering where a delicious risotto is served in a beautiful bowl. From there, visitors should be able to find out about the bowl and its designer, get the recipe and buy the bowl.

Mapping and testing the site

To understand how the different content should cross-link we created a wall chart. We identified silos, such as recipes, products and forum posts and connected them with arrows. (Jamie came in to see it. He liked it a lot. He's a nice bloke.)

From there, we created a wireframe prototype to represent these ideas ready for testing with users. The most successful website wireframes tend to contain "real fake content" - lorem ipsum doesn't give users a real feel of what the final experience will be like. These wireframes had to contain a lot of visual imagery showing example products, people and situations where they might be used.

User feedback told us two things:

Firstly, we needed to keep our feet on the ground. If you're going to show a desirable bowl customers will soon need to find links to the plate, side plate and coffee cups that match. It also reminded us that you can never be too clear about practicalities like delivery information, pricing and the checkout process.

Secondly, the connected, contextual, useful and inspirational idea made for a great user experience. Jamie Oliver fans loved to use it. And it provides the kind of rich information and emotional content that people need to help them make purchase decisions.

Take a look at Jme

The site is quickly growing into its new home. It's got genuinely fabulous kitchen and dining room stuff, herbs, books and DVDs - all selected by Jamie himself. There are lots more products, recipes and articles coming on all the time. We think it's great to look at and delightful to use.

As Jamie would say: "Nice one!"

Team: Peter Otto, Genevieve Chapman (Splendid), Simon Parbutt (Splendid)

Information Age has published a great article about the importance of accessibility. As well as summarizing the legal requirements and the WCAG 2.0 ratings system it goes on to point out that accessibility is beneficial to all and therefore must be a driving force behind the design rather than a late consideration.

Our very own Brad Haynes discusses his experience whilst working on the design of Ocado. The Ocado team were determined to "do the right thing for consumers". This meant not only being compliant, but also considering accessibility in a far more thorough way as a core goal of the design process. Brad cites  examples from Ocado including copy length, page layout, technology choice, processes & story structure, site structure and page 'weight'.

If a site is truly accessible then it's truly usable

Flow believes that accessibility is a positive design decision which achieves far more than legal compliance.

The original iPod Shuffle had a clear proposition; a cheap, simple, and minimalist music player. Technically the first iPod to use flash memory and physically the smallest, it lacked any display, scroll wheel or playlist management features. The constant need to control, skip, manage, and navigate was replaced with a simpler and more relaxed lack of control. Instead, the device simply shuffled music at random or played tracks in order. The front of the device had a simple interface:

• Play/Pause
• Next Song/Fast Forward
• Previous Song/Fast Reverse
• Volume adjustment

On the back was a three-position switch to play music in order, or shuffled or to turn off the unit.

The second generation was just as simple as the first, but had more storage and less than half the size.

On 11 March, 2009 Apple released the third-generation Shuffle.

One of the key design decisions was to simply not have any buttons, apart from a button that switches between 'Off', 'Random' and 'Order'. All controls are now part of the earphones.

According to Apple:

The new iPod shuffle is amazingly small and even easier to use.

But is it easy to use?

Soon after the launch, forums, social media networks and blogs started to criticise the new Shuffle. Whilst some disliked being dependent on using Apple's earphones, others criticised the new interface. Physically, the control could be difficult to grab during sporting activities or for those with bigger hands, but more importantly, most of the functions are controlled via a central button that has no labels.

The lack of visual display raises a design challenge. Unfortunately, touch is a less accurate sensory mode than vision and typically slows users down. Apple could have designed an interface with elements that could have been recognised through tactile attributes such as feedback, resistance, size, weight, and/or texture. The father and grandfather of the current Shuffle are good examples of such a control. However, the solution was to include VoiceOver technology, a feature that speaks 14 languages and plays back track and playlist names. Although a minor issue, VoiceOver struggles with pronunciation. Perhaps in the future, additional language information will be included with each track.

One button, nine commands

Apple was once famous for the one-button mouse. Although historically some suggest that this decision was based on cost, it was often argued that one button is all you needed. The one button became a symbol of simplicity. In contrast, the new iPod Shuffle has a central button that accepts many user commands. In fact, this 'one button' handles 9 inputs:

1. click
2. click & hold
3. double-click & hold
4. triple-click & hold
5. triple-click and hold within 6 seconds
6. triple-click and hold after 6 seconds
7. click until a tone is played
8. click until you hear a name
9. click & hold until exit

There is no direct cognitive mapping between users' goals and the required actions. For example, why does 'double-click and hold' fast-forward a track, but 'triple-click' rewind? Moving to the next track is achieved by double-clicking. So how do you expect to move to the previous track? Did someone at the back just say "triple-click within 6 seconds of the track starting"? Correct.

 Poor learnability?

Ultimately, if the device is used frequently, many users will move from being novices to experts. However, if learnability is poor, some users will remain perpetually intermediate and potentially frustrated.

Learnability is inherent in interface features that allow novice users to understand how to use a device and how to attain optimal (level of) performance. Learnability is based on five main factors:

• Predictability: operation visibility - what elements of a user's knowledge from past interactions with this device can help to determine the outcomes of future interactions?
• Familiarity: guessability - to what extent can users' knowledge from other systems and real world objects could be applied to interactions with the device?
• Synthesisability: how does the interface help a user to asses the effect of past actions on the current state?
• Consistency: likeness in behaviour. In this context consistency is related to user inputs and the subsequent output responses.
• Generalisability: support for the user to extend their knowledge to other applications and devices.

In the case of the Shuffle, lack of visual display could slow down skills acquisition. The design is not based on familiar metaphors, and poor learnability may increase cognitive load. Many users will not be familiar with the Shuffle's interface, apart from iPhone users who use a similar earphone-based controller.

As a robust device consistency between actions and auditory feedback that arises as a consequence will be high and usage is likely to be frequent. Therefore, for many users learnability will eventually take place. It is possible that Apple plans to extend this interaction model to other devices. For those who mastered this control acquiring this skill will become generalisable and useful.

Does it matter?

So it might be difficult to learn. Arguably, it has beautiful industrial design, long battery life and impressive storage capacity. Apple could sell many of these fashion accessories to users who would simply click to play whilst sitting on the train, running, or going to the gym.

The best way to gain an in-depth insight would be to test the Shuffle with users. In the next few weeks we are planning to evaluate the Shuffle in one of Flow's experience laboratories and analyse its performance and user experience.

- Ofer Deshe, Principal User Experience Consultant

Thanks to Thibault Baradat-Bujoli for the original illustrations

We seldom discuss mediocre experiences with our friends. The ones which do get mentioned are the exceptional - both great and bad.

A bad experience is one where:

• My needs and desires are not provided for.
• The product itself doesn't deliver as promised or is confusing / hard to learn.
• The interaction (at POS and afterwards) is confusing, patronizing, inflexible, or unusable.

A great experience is one where:

• The concept is utterly relevant for me.
• The product itself exceeds expectations and allows me to focus on the task in hand.
• The interaction (at POS and afterwards) is simple, fast, accessible and structured appropriately for me.

Countless online communities & blogs have built up around recommendations and many ecommerce sites have integrated a recommendation network into their shopping experience e.g. Amazon. Many books have been written about the power of recommendation in marketing including The Tipping Point by Malcolm Gladwell and Buzzmarketing by Mark Hughes. Terminologies have developed around the roles individuals play in such recommendation networks (Connectors, mavens & salesmen in the Tipping Point). If you want to know more you can get the books... suffice it to say that recommendations work best the closer the source is to you... or the most highly respected the source.

The power of a recommendation is undeniable - it creates buzz which is the marketing holy grail.

The first step in getting recommendations is to create outstanding experiences. In designing any product or service the 3 key questions are:

1. Is the product/service relevant for the target market? Does it address the real needs and desires and will it fit effectively into the context in which it will be placed?
2. Is the product/service marketed effectively to enable customers to fully understand its potential whilst retaining clarity? Is it intuitive, accessible and enjoyable?
3. Do the sales and post sales processes support customers' behaviour? Will they allow them to engage in the optimal way to ensure a great experience?

As a producer of such experiences the only way to ensure you are getting this right is to involve the end users throughout the design process from concept development through functional specification and visual design to marketing and post sales. See the Flow case studies for numerous examples across different industries and product types.

It's great to hear people being positive about something which went right to such an extent that they make conversation of it. Let's learn from some of the positive experiences out there. Please add a line or two on your great experiences.

Thanks to Pierre Lenfestey for the use of his artwork.

The unprecedented economic situation means that many products, services and entire businesses are now based on an understanding of their market which is outdated. There's a real danger of businesses providing square pegs for their customers' metaphorical round holes.

In a previous life, I was a recipient of the famous 1995 Bill Gates sea-change email. From that day on, the strategy at Microsoft changed. BillG echoed many business owners around the globe who hurried to adapt their business plans to incorporate online channels and internet connectivity. This simple change in direction has shaped the commercial landscape ever since. Those who adapted successfully and who understood the commercial opportunities and changing customer requirements have been the most successful.

The latest sea change is not one led by technology innovation, but by a dramatic shift in consumer behaviour. In all walks of life attitudes are changing, compounded by the constant media barrage of stories of economic doom and gloom.

"Deep recessions deliver more than just an economic shock: they can shock an entire social system into new ways of thinking and organizing." NESTA (2008) Attacking the recession: How innovation can fight the downturn.

It is all too easy for businesses to focus inwardly to drive efficiencies, or to focus energies on increasing revenue through additional marketing. These energies will be wasted, and even potentially damaging, if the product or service has become fundamentally out of line with the customers' needs & expectations.

We will see...

• Motivations to spend and interact changing, driven by a focus on essentials, economizing, escapism & networking.
• Brand loyalties are shifting as people openly look towards cheaper alternatives and shun luxury goods.
• Trust is no longer a given with established brands... Trust must now be earned in other ways and the risk / reward balance for the customer must be carefully considered.
• The decisions people make and the process by which they research options will be different. The network will play an ever increasing role as people search out value.
• The susceptible moments when customers may be open to up-selling or cross promotion are likely to shift.
• Market segments will rearrange themselves based on potentially new criteria related to goals.
• The list could go on...

Although the effect of these changes varies across sectors, businesses can no longer believe they ‘know' their customers based on old research, results or instinct. While companies focus inwardly on reducing the impact of the recession, the distance between their customer insight and the real customer attitudes and behaviour is growing. Their products and services run the risk of being upstaged by competitors who innovate based on a new understanding of the changing market and user requirements.

This is not a short term situation... these changes will have a lasting impact regardless of the duration of the recession. You only have to look at the attitudes of a generation who have passed through previous economic downturns to see the way it affects their long term attitudes as consumers.

What can be done?

At Flow, we believe that you need to get under the skin of your customers in order to develop and improve products & services. Many of our own case studies illustrate where this user centered approach has led to increased turnover and profits, and reduced costs.

We've previously blogged about a 3 pronged approach to designing in an economic crisis. All 3 require a fresh understanding of your customers:

1. Innovate: The situation provides real opportunities for companies willing to innovate based on fresh user insight. History has shown that recessions are ultimately great drivers of innovation. He who dares wins... UCD enables innovation with minimum risk because you know you're building the right thing from the start.
2. Optimise: It may well be that your existing products and services need a little adaptation for the changing market. Some small improvements can lead to large rewards. Fresh user insight will point you towards some optimizations which are likely to range from simple messaging changes, through to new ways of navigating.
3. Cut costs: A cross channel view across your complete customer will highlight some areas for cost cutting whilst enhancing the total customer experience. Online retailers are currently reaping the rewards whilst their high street rivals are struggling to maintain expensive, and less convenient, channels to market.

User centered design is available in shrink-to-fit. It doesn't need to be expensive, but it must be included if you want to capture the attention of a rapidly changing market.

- Meriel Lenfestey, CEO & founder of Flow

On Thursday evening, 19th February 2009, I was privileged to be at the Grosvenor House Hotel in London for the HSBC Rail Business Awards to co-receive the Information Technology Excellence of the Year Award for the new National Express East Coast (NXEC) booking engine and website.

As any of you reading this who have used the NXEC booking engine know, it dramatically simplifies the process of finding and buying rail tickets online...not just on NXEC routes, but for any train in the UK.  We have blogged before about the intuitive user interface and its cutting edge use of AJAX technology as well as the positive customer feedback and improved business results for NXEC before.

We (and NXEC) have also received lots of accolades from customers and the industry about how great the new booking engine is.  So it fills us with a great sense of pride and accomplishment to receive this well-deserved acknowledgement from the Rail Industry for all the creativity and teamwork that went into making it happen.

It has been a long road, but the hard work and effort has paid off, not just because we won this award, but because we succeeded in creating a first-of-its-kind, innovative and successful new booking engine for trains that will set the standard for all that follow, in terms of business performance, ease of use and customer satisfaction. It is also a clear demonstration of how User-Centred Design makes a tangible difference to customers and business.

I just want to take a moment to thank the entire NXEC team from Flow:  Simon Hatch, Alejandra Obregon, Martina Schell and Kelsey Smith; our partners at Splendid: Paul Bishop, Simon Parbutt, Alistair Thomson and Karl Wortmann; the team at Atos Origin who built it:  Graham Bodman, Richard Phillpot, Ian Collier, Eleanor Waldron and Chris Rees; and the team at Tullo Marshall Warren (TMW) for bringing the marketing website together.

But perhaps most importantly, I want to thank Emma Passey and the entire NXEC team for their vision, passion and perseverance.  We couldn't have done it without you!

Congratulations to everyone. A well deserved award!

- Ian Worley, Director of User Experience at Flow Interactive

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Download Case Studies about this project:

• National Express East Coast Booking Engine Case Study (78k .pdf)
• National Express East Coast Website Case Study (92k .pdf)

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Even as online retail struggles, you can keep sales figures alive by optimising the site you have. One area to look at is improving what happens to your customers when things go wrong.

A classic and expensive error

During my previous life as a developer, I lead the prototyping for enhancements to a clothing and home wares website. Like any sensible UCD practitioner, I wanted to get measurements to help me understand where customers were going on the current and revised site.

Just one error message

When it came to errors, the need for more detailed measurements was particularly urgent. We didn't know which pages or processes were throwing up errors. We had no detailed analytics and only one error page for the whole site: "An error has occurred. Press Continue."

I knew that we needed to write individual, polite messages which would reassure people enough to carry on, but we didn't even know yet what those errors were.

Once the analytics were up and running, we could quickly see which pages occured before and after the error page. This let us identify the user journeys where the errors were triggered. So we were able to write custom messages, things like "We're sorry, we've had a problem processing your order. Your card hasn't been charged yet. Please click checkout to try again." We also provided a customer care number together with a code for continuing the transaction offline.

Return on investment

Within a month the percentage of completed purchase journeys increased a modest 0.5%. Putting it in some perspective that 0.5% was worth £27,000 a month on average - or over £250,000 per year.

And all this was hypothesised, diagnosed and implemented over 2 weeks, at a staff cost of approximately £8,000. That's a great return on investment from paying attention to the detail of the customer experience. Each one of those customers had a chance to complete their purchase, and to remain a loyal customer with a chance of purchasing again in future.

6 error message tips

If I've inspired you to revist your site's error messages, remember these golden rules as you go:

• Be polite: Don't make your visitor feel like they've done something wrong; accept responsibility for the problem, say "sorry", "please" and "thank you".
• Use plain English: Remember that the people visiting your site aren't developers, and don't know Java from JavaScript or 404 from 500 (unless you're writing error messages for Slashdot or the MSDN that is).
• Reassure: Especially when the visitor's money is at stake, it's important to make sure that people understand that nothing catastophic has happened.
• Make it brief: Your visitor isn't interested in the exact whys and wherefores, be succinct.
• Help people recover: Provide them with a clear path out of the woods - even if that means calling someone on the phone.
• Tag them: Track where people go and what they do before and after experiencing an error on your site, and track what happens as you make changes.

Optimising is just one of three design-based strategies for beating an economic downturn:

• Innovate
• Optimise
• Cut costs by improving the customer experience

User centred researchers and designers working in developing markets are finding new ways to understand their target users.

In the early 70s, Prof Geert Hofstede ran surveys with IBM employees worldwide and produced a set of four cultural dimensions which he used to categorise countries in terms of national tendencies. His four dimensions were:

• The Power Distance Index, which looks at how much people accept and expect that power is distributed unequally.
• Individualism, which considers how far people operate as part of extended loyal groups and families.
• Masculinity, which considers how far men's values are from women's in a society.
• The Uncertainty Avoidance Index, which measures a society's tolerance for uncertainty, ambiguity and diversity of approach.

It doesn't take long to notice that Hofstede's ideas have little to do with interaction design as such. They are focussed on management and communications and offer analysis at the level of general tendencies; they are not about use. But Prof Hofstede's name has become synonymous with cultural research in interaction design. He is quoted extensively. He is held up as evidence that tidy answers exist somewhere to untidy problems.

Interaction designers do need guidance on how to handle cultural diversity when designing technology with international reach. But that guidance may not be best in the form of metrics and measures. The OzCHI 2008 conference on Designing for Habitat and Habitus explored cultural aspects of designing. And every single experienced researcher came back to the same point: The best way for designers to understand the cultures they are designing for is to go get first hand experience.

Good listening

The OzChi2008 conference began with a workshop on 'Inclusivity, Interaction Design and Culture' . Participants discussed flexible and fine-grained ways of understanding difference in interests, values and use of technology. This understanding, it was agreed, did not come from metrics focussed on national characteristics.

So what did these researchers advocate instead? ... Read more »