An alternative display for visualizing and managing group schedules

Microsoft Outlook is one of the most widely used applications in the world but its calendar has frustrated many users who want to view several schedules at once. With Outlook you can view multiple calendars side by side but after you add a few calendars the information disappears into a forest of heavy gridlines and background colors.

Here are some alternatives to the cluttered calendars offered by Outlook and other off-the-shelf solutions. The alternative designs incorporates many ideas from Dr. Tufte's books and this discussion forum.

The following thumbnail images are linked to the original images, which were all recorded at 1024x768 resolution on a 19" monitor.

Week view

Each display above represents a five day view of 10 calendars. Each display arranges appointments in columns with a day for each column and hour divisions running vertically. However, Outlook 2003 and 2007 render the individual calendars as columns, which tends to stretch each appointment vertically while the alternative display organizes the calendars as rows, which tends to stretch the appointments horizontally.

Outlook 2003 and 2007 are both characterized by heavy grids and background shading and the calendar names, dates and appointments are truncated and camouflaged. The alternative display has a cleaner look, a much more subtle grid (which can be turned off by the user) and calendar names, dates and appointment boundaries are not obscured. In most cases there is space for a text label on the appointment but tooltips are available in lieu. The appointments can be colored using Outlook's default colors (representing free/busy, out of office and tentative) or, as show here, with category colors (see legend to the right). Hour labels are only drawn for the first calendar to avoid unnecessary repetition.

Month view

When the time scale extends to a month the differences between the Outlook versions and the alternative display become more pronounced. In Outlook 2003 the appointments have disappeared altogether while in Outlook 2007 the appointments are visible but only just. To be fair Outlook 2007's month view appears to display seven day weeks rather than five day weeks so space is taken up somewhat unnecessarily by weekend days, which in most organizations is beyond normal working hours. The week range is also repeated in a redundant fashion for each calendar. Another problematic issue is that the layout of appointments has changed from the week view show in the first triptych. Each week of the month is now laid out on a different row so the user has to contend with three different time axes.

In contrast, the alternative display is able to clearly render a month of appointments (even in the thumbnail). The layout is consistent with the week view in that the calendars are still rendered in rows and each column of data represents a day. The time scale labels are dynamically adjusted for the displayed time period and to fit within the available space.

The display is also consistent in hiding weekend days although the user can add these as required. The alternative display can also be rendered as working hours (eg 0900-1700) or a full 24 hour day.

A feature of the alternative display is a reference calendar that provides context if the user chooses to zoom in and pan across an area of the main display to view part of the calendar in more detail. The blue shaded rectangle in the reference calendar changes size and location to help orientate the user. A check box allows the user to constrain the zoom so that the horizontal axis is scaled but not the vertical axis.

Alternative display modes

The alternative display is implemented using Scalable Vector Graphics, which is the web standard for describing two-dimensional vector graphics. The use of SVG facilitates coordinate transformation and thus it is possible to translate and scale objects like appointment rectangles. In the screen shots above the appointments have been transformed into two other modes: a timeline view and a bar chart view.

In the timeline view the hour labels have been removed as the horizontal time axis now represents a continuum of time, which can be useful when viewing activities that extend over several days like project tasks.

In the bar chart view the appointments have been collapsed into a stack rising from the bottom of each calendar row. The hour labels have been replaced by a percentage scale that represents the utilitization of the resource. The percentage utilization is calculated based on either the number of working hours in a day or the full 24 hours depending on the option chosen by the user.

Choropleth Overlays and Aggregate Bar Charts

Using SVG transformations the display can be viewed as separate side-by-side rows of calendars or combined in a single row that covers the plot area.

When the calendars are combined they are superimposed on each other in a series of overlays that fill the display. By giving each appointment a monochrome color and an opacity that is proportional to the number of calendars (in this case ten) the display becomes a choropleth. White areas indicate that all the resources are available while progressively darker areas indicate times when more resources are busy. This can be useful for analysing resource availability and booking meetings. Moreover, as the user moves the cursor across the display the resource names listed on the left side change color to represent the category of activity they are participating in. Individual layers can be turned off. Meeting rooms that have insufficient capacity for the number of people in the group are flagged and their calendars are automatically hidden.

When the calendars are combined in bar chart mode, the appointments of each resource are stacked together to produce an aggregate view of the group. The display can be changed to sort appointments by category or resource. In the latter case the appointments of each resource are assigned a common color.

Longer term calendar views

Sometimes it is useful to look at calendars over a much longer period of time. In the above examples the period is twelve months or twenty to fifty times the maximum range that Outlook can display legible appointments. In the alternative display, individual appointments are discernable at 1024x768 giving each calendar a sparkline appearance.

Again the display is consistent with the week and month views of the same data. The timeline view is less helpful given the appointments are mostly less than a day's duration but even the thinnest appointment rectangles will produce a tooltip when moused over. All the same functionality is available in the year view (zoom and pan, choropleth overlays and aggregated bar charts).

Detail within context

This last screen shot illustrates how a single calendar can be displayed at two time scales simultaneously. This enables the user to see both the big picture context while looking a smaller periods of time in more detail. The user can change the time span in the lower calendar display by clicking on the arrows (to move one day at a time), the scroll bar (to move one week at a time) or by dragging the slider on the scroll bar. The two time scales are linked by a translucent polygon object that changes shape as the user navigates the lower calendar.

Conclusion

The alternative displays demonstrate a number of different ways of visualizing calendar data. Although the alternative displays are compared with Microsoft Outlook they are not tied to a particular implementation and can be used in conjunction with other calendar data sources. SVG documents are not only derived from a World Wide Web standard but they can be viewed in multiple browsers and by many mobile devices.