Please note the last 5 principals have been cribbed from ‘Shortboredsurfer‘ and great principals they are too. It’s not my intention to claim them as my own, just compile them with the others I collected to provide a list I think is the most useful.
The following functional principals, along with the measurements of Usefulness, Findability, Accessibility, Desirability, Usability and Credibility are my little list of ‘must-haves’ when designing stuff. I’ll likely continue to add stuff to the list when I find it. So keep checking back.
1. Speed
First and foremost, we believe that speed is more than a feature. Speed is the most important feature. If your application is slow, people won’t use it. I see this more with mainstream users than I do with power users.
2. Instant Utility
What this means is the service is instantly useful to you. If you build a service and the user has to spend an our configuring the service, setting it up, importing contacts, doing a lot of data entry, I don’t think people are going to – most people aren’t going to put up with that. The service has to be useful right from the start.
3. Software is Media
This is one that I got a lot of questions on. My view is that software is media today. Particularly consumer software, when people use it, they approach your software in the same way they would approach media. When I say media, I’m talking about a magazine, or a newspaper or a TV show. Software and web applications, Apps and gadgets need to have an attitude, and a style and uniqueness.
4. Less is More
Less is more, and I really believe this, particularly early on when you launch something. Over time, you can grow the utility of your service, and Facebook today probably offers 20 or 30 different features of significance in their service. But, when they launched, it was really quite simplistic. I think that’s true of most great services.
5. Make it Programmable
Talking to a group of web app developers, I think this probably goes without saying, but I think it’s important to make your application programmable, and make it possible that others can build on top of or connect to or add value to, in some way, your web application. That means API’s, and in my opinion read/write API’s.
6. Make it Personal
Personal means many things to many people, but essentially, it’s a lot like the prior slide. You want third-party developers to infuse your application with their energy. You also want to make your application infused with your users’ energy. The more of their data and their personality and energy that they can contribute to your application, the more ownership that they feel of it, and the more likely they are to advocate it and become, in effect, your marketing force. It’s very important to make your application personal for everybody. Clearly, user-generated content lets people start to feel ownership of your web application better.
7. Discoverabilty
When you launch a web app, it’s a needle in a haystack. There are hundreds of thousands, if not millions of web apps out there on the World Wide Web, and how is anybody ever going to find yours? At its base level, for me, this means search engine optimization. You have to understand search engine optimization and you have to understand the rules; you’ve got to know how to do it. You have to build your application from the ground up to be discovered by Google, and optimized for Google.
8. Clean
Clean, to me, means that the application cannot be busy on the page. You need to be able to look at it and not be bothered with lots of stuff. It’s white space, or dark space; it doesn’t really matter whether it’s white or dark, but lots of space. I think big fonts, not too much functionality presented on any one page. Make it very inviting, and make it so the people know, right away, what they need to do.
9. Playful
Last but not least, is playful. We have 6 words that we live by at Union Square Ventures. Only one of them actually made it into this deck. The 6 words are: mobile, social, global, playful, intelligent, and I’m forgetting what the last one is so I’m going to fail today, but in any case, that’s kind of what we think about thematically in terms of web apps. Only one of them made it onto this slide deck, and that’s “playful”.
10. Viral
Viral conjures up visions of Old Spice Man, but it’s more than that – It’s the power of pass-it-on… being able to share things with your peers, friends and family and let them join you in the experience and then tell their peers, friends and family to expand their experience too. It’s not about chuckling at a video on YouTube and emailing a link or Tweeting a response, it’s purer than that – Viral is about joining in and taking other people along for a ride. Here are the golden rules of viral:

- Web-based – Viral loops are far better suited to the frictionless world of the internet
- Free – Users consume the product at no charge; after aggregating a mass audience, you may be able to overlay various revenue generators
- Organizational technology – These sites don’t create content, their users do. They simple organize it, but facilitating can lead to a mass audience – Just ask Google.
- Built in virality – Users spread the product purely out of their own self-interest and, in the process, offer a powerful word-of-mouth endorsement to each subsequent user.
- Network effects – The more people who join, the more people there are who have an incentive to join
- A point of non-displacement – A tipping point, after which it’s nearly impossible to take a company down.
11. Match Experience & Expectations
When using a product or service for the first time there is likely to be an element of learning needed to get to grips with it. This learning curve can often be an uncomfortable experience especially if the proposition doesn’t feel familiar. Match your audience’s prior experiences and expectations is achieved by using common conventions or UI patterns.
12. Cognitive load
Cognition is the scientific term for the “process of thought”. When designing interactions we need to minimise the amount of “thinking work” required to complete a particular task. Another way of putting it is that a good assistant uses their skills to help the master focus on their skills.
13. Functional Layering
The Pareto principle (also known as the 80-20 rule), in the context of interaction design, is the rule that 20% of the functionality is used 80% of the time. Therefore we should make the most common or important functions easiest to find. We can do this by hiding or reducing the prominence of infrequently used or advanced functions.
14. Mousing
In my daily interactions ‘mousing’ is becoming less of an issue as I begin to rely more on touch screen interfaces such as my iPhone and iPad. However, in the classic desktop environment ‘mousing’ relates to the ease in which you are able to move between controls, which is described best through Fitts’ law.
Fitts’ law is a model of human movement in human-computer interaction (HCI) and ergonomics which predicts that the time required to click an object is proportional to the distance and inversely proportional to the object size.
With key functions or sequential mouse-operated controls we need to maximise the size of the controls and minimise the distance between them. This not only improves efficiency but in certain instances can reduce the risk of error.
15. Hierarchy of Control
The hierarchy of influence between elements should be clearly apparent. Generally, controls which affect an object, should be grouped with the object, such as zoom controls on a map.
Controls which influence a group of objects should be associated with the entire group, forming a hierarchy.