Many partners have been asking about Office Web Applications. Here’s some information on the design and engineering principles.
Tenet #1: Trustworthy
First and foremost we want to build web applications that users can trust. Many elements regarding trust are quite common amongst web applications. For example, most web applications need to be reliable, available, responsive, respect user's privacy, backup data, etc. For the purpose of this blog post I will not spend time talking about these aspects of 'trust' as most web applications share these principles. What I do want to discuss is how our team views 'trust' in the context of web productivity applications and some specifics about what we are doing to earn trust.
Round-tripping (or preservation) of documents:
When a user works with a document in an Office Web App, the Web app will preserve the data in the document, even if the Web app doesn't support a specific feature. For example, the Word Web App will not support editing 'Watermarks' in the initial version. However if a user opens a document with a 'Watermark' in the Word Web App, makes some changes and saves, the 'Watermark' will remain in the document. It is very important that when customers use the Web apps they can do so trusting that they will not lose data or 'mess up' the document.
Another example is that I may create a spreadsheet in the Excel desktop app and then share it with a friend. My friend may want to add data or change numbers, even though she doesn't have Office installed on her machine. Using the Excel Web App, she can make changes knowing that the integrity of the spreadsheet will be preserved. The formulas, charts, worksheets, pivot tables will all continue to be intact in the spreadsheet (unless changed by my friend).
While this may seem obvious, it’s harder than it seems. Others use an 'import/export' model and convert the documents to a simpler form for editing on the web. This approach works adequately for some scenarios, but it takes just one or two instances of content being 'lost in translation' for users to lose trust in the Web Apps. With Office Web Apps, we want people to use them with confidence and knowing that their content will be safe.
Tenet #2: Familiar Office User Experience
We want Office Web Apps to be easy and fun to use. We know that the 'Office' brand comes with high expectations and we aim for the Web apps to have a high quality look, feel, and level of usability. We use the word 'Familiar' in this tenet as there are hundreds of millions of Office users today and that consistency with existing experiences will make it easier for customers to work with the Web apps' interface.
It is important to note that the tenet is not called "Replicate the Office desktop apps' interface exactly in the browser". We recognize that the web platform has different conventions and we want to ensure that the Web apps utilize the best of the web and take advantage of the web platform's strengths. An analogy is Mac Office and Windows Office. While much of the UI/behaviour is consistent, the interfaces are not identical as each is optimized for the underlying platform.
Perhaps the most obvious place where customers will recognize our efforts towards this tenet is in the look and feel of the application. The icons will be familiar, the text of commands will match the desktop apps, all the apps use the 'Ribbon' interface, etc. In the individual apps you can expect to see sheet 'tabs' at the bottom of Excel, a view of the slides on the left in PowerPoint, or the familiar formatting commands in Word.
We’ve also made a big investment in consistent behaviours. This includes some of the basics that Office users have come to expect like AutoCorrect and background spellchecking. I'll provide a more detailed example to illustrate the level of thought that goes into building a productivity application. Try the following in the text editor of your choice:
1. Create a new document
2. Insert a table at the very top of the document
3. Add text above the table
In Word (both the desktop app and the Web app), if you simply hit 'enter' while your IP (insertion pointer) is in the upper-left of the table it will create a new paragraph above the table. This makes sense but requires special logic, as normally hitting 'enter' in a cell creates a new line in that cell. Most users likely never notice this, but without this type of subtle logic editing can be frustrating. This attention to detail is part of what separates basic editors (or spreadsheets/presentations) from applications designed to provide an 'Office quality experience'.
Below is a visual showing this behavioural difference between Microsoft Word (top) and Microsoft Writer (bottom).
Tenet #3: High Fidelity
For many people, Office documents are their 'work product'. Most people take pride in their work and their documents. With Office Web Apps, we want to ensure that users can view and share content with the confidence that others will see their work as intended. We've even seen a major product category (Adobe PDF/Acrobat) designed for this express goal.
With the Web apps, we use the term 'fidelity' to span a broad spectrum from visual fidelity (e.g. formatting and layout) to data fidelity (e.g. calculations and formulas) to behavioural fidelity (e.g. builds/animations in presentations). Office customers will expect that their content will look and act the same on the web as it does on their PC. For a scientist, this could mean that a design document has the correct layout, diagrams, pictures, and pagination when shared. For an administrator they want to be sure that the formulas always compute the same way and that their charts or tables accurately represent the data. A teacher or student will want his/her slide deck to look professional and as designed, builds/animations to work, and for the notes to be available.