An Exploratory Study of Personal Calendar Use
Manas Tungare, Manuel A. P
nones, Alyssa Sams
Center for Human-Computer Interaction
Department of Computer Science
Blacksburg, VA, USA
In this paper, we report on ﬁndings from an ethnographic study of how peo-
ple use their calendars for personal information management (PIM). Our partici-
pants were faculty, staff and students who were not required to use or contribute
to any speciﬁc calendaring solution, but chose to do so anyway. The study was
conducted in three parts: ﬁrst, an initial survey provided broad insights into how
calendars were used; second, this was followed up with personal interviews of a
few participants which were transcribed and content-analyzed; and third, exam-
ples of calendar artifacts were collected to inform our analysis. Findings from our
study include the use of multiple reminder alarms, the reliance on paper calendars
even among regular users of electronic calendars, and wide use of calendars for
reporting and life-archival purposes. We conclude the paper with a discussion of
what these imply for designers of interactive calendar systems and future work in
Personal Information Management (PIM) is receiving attention as an area of re-
search within the CHI community [Barreau et al., 2008, Bergman et al., 2004, Teevan et al., 2006].
PIM research mostly is concerned with studying how people ﬁnd, keep, organize,
and re-ﬁnd (or reuse) information in and around their personal information space.
Calendar management, one of the typical PIM tasks, is done today using a variety
of systems and methods, including several popular paper-based methods: At-A-
Glance, one of the largest suppliers of paper planners, sold more than 100 million
calendars in 2000
For computer-based systems, calendar management is often integrated into
email clients (e.g. Microsoft Outlook); it is one of the most common applica-
tions in all personal digital assistants (PDAs, e.g. Blackberries and iPhones), and
there are several online calendar systems (e.g. Yahoo! Calendar, Google Calendar,
Apple Mobile Me). Date- and time-based information is ubiquitous, and is often
arXiv:0809.3447v1 [cs.HC] 19 Sep 2008
available through many means such as postings on ofﬁce doors, displays with dated
announcements, through email conversations, written on wall calendars, etc. The
result is that calendar information tends to be pervasive.
In this paper, we set out to explore how people use calendars in the presence
of varied technological options. We are interested in understanding how calen-
dar information is managed given the availability of these platforms. After a brief
review of related work, we proceed to discuss our ﬁndings from the survey, inter-
views, and artifacts. From these, we suggest several opportunities for designers
of future electronic calendar systems, and conclude the paper with a discussion of
future research in personal information management.
2 Related Work
There is a long history of calendar studies in human-computer interaction litera-
ture. Early research on calendar use predates electronic calendars. In 1982, Kel-
ley and Chapanis [Kelley and Chapanis, 1982] interviewed 23 professionals to dis-
cover how people in the business world kept track of their schedules. They found
that for the individuals interviewed, calendars were indispensable and showed a
lot of diversity in their use. The use of multiple calendars was prevalent, and a
wide variation was seen in the time spans viewed, as well as in other aspects such
as archiving, editing and portable access. Many of the problems identiﬁed in pa-
per calendars could be solved in electronic calendars, and they concluded with a
list of features for emerging electronic calendars to implement. Soon afterwards,
Kincaid and Pierre [Kincaid et al., 1985] examined the use of paper and electronic
calendars in two groups, and concluded that electronic calendars failed to pro-
vide several key features such as ﬂexibility, power, and convenience, that paper
calendars did. They recommended many useful features to be incorporated into
electronic calendar systems as well.
Nearly 10 years after Kelley and Chapanis’ original study, Payne [Payne, 1993]
conducted interviews with 30 knowledge workers about both calendars and to-
do lists, followed by a task analysis of his observations. He concluded that the
central task supported by calendars was prospective remembering. Prospective
remembering is the use of memory for remembering to do things in the future, as
different from retrospective memory functions such as recalling past events.
Payne reported that other uses of calendars were not as well-supported by sys-
tems at the time: features such as automatic scheduling were found to be detrimen-
tal, since it allowed users to schedule appointments without simultaneously being
able to browse the other appointments in the calendar opportunistically. Electronic
calendars of the time did not support the rich layout and typography of paper cal-
endars, nor did they allow the scheduling of events that did not have a speciﬁc
time associated with them. He concludes with a discussion how calendars could
be designed to support the prospective remembering task better.
Groupware in the ofﬁce or corporate context has been studied widely: Grudin
[Grudin, 1996] reported that many ofﬁce administrators who used online calendar
systems printed the calendars of their managers almost daily. Grudin and Palen
[Grudin and Palen, 1995, Palen, 1998, Palen and Grudin, 2003] explored the fac-
tors that contributed to adoption of groupware calendars, and the role of peer pres-
sure and network effects in expanding the use of a shared calendar system for
meeting scheduling. Palen [Palen, 1999] explored the inter-play and co-evolution
of individual demands, social aspects and deployment issues in groupware calen-
dar systems. Calendars are often also used at home, but this area has not received
much attention in the literature; a notable exception is [Crabtree et al., 2003]. In
this paper, we focus on the personal use of calendars (at work or at home) but do
not explore the collaborative aspects of calendar systems in detail.
Several interesting design concepts have been suggested to make electronic
calendar systems less error-prone and smarter. These cover a wide range, from
systems that retrieve tasks from email messages [Horvitz, 1999], to systems that
learn from users’ behavior to recommend intelligent defaults [Mueller, 2000], to
calendar systems that predict attendance at events [Tullio et al., 2002]. Beard et al.
[Beard et al., 1990] assessed the effectiveness of a priority-based calendar proto-
type and concluded that integration with other personal information systems (such
as email) would make the system more useful for users. Visualizing calendar in-
formation on desktop computers and mobile devices has been explored in several
studies [Mackinlay et al., 1994, Bederson et al., 2004].
In the ﬁeld of Personal Information Management, the management of various
information collections such as ﬁles [Barreau and Nardi, 1995], folders [Jones et al., 2005],
email [Whittaker and Sidner, 1996] bookmarks [Abrams et al., 1998] and cross-
collection issues [Boardman and Sasse, 2004, Kaye et al., 2006] have been studied
widely. Calendars are an important part of users’ personal information, and this
domain can beneﬁt from a re-examination in the wake of electronic and ubiquitous
Jones [Jones, 2004] framed the problems in PIM in terms of the canonical tasks
of keeping, organizing, and re-ﬁnding. Keeping any kind of information involves
a tradeoff between the likelihood it will be recalled in the future, and the costs of
capturing and retaining it. Organizing involves ﬁling it away such that it can be
retrieved easily in the future, and while keeping the cost of organizing less than
the cost of ﬁnding. Re-ﬁnding is a different problem from ﬁnding, since there are
aspects to encountered information that make it personal.
With the increased use of mobile devices, more and more calendaring tasks
are performed off the desktop computer. Perry et al. [Perry et al., 2001] report on
issues faced by mobile workers, their need for access to people and information
located remotely, and the planful opportunism they engage in when utilizing their
dead time for tasks.
3 Study Description
The ethnographic approach we took in this study follows techniques commonly re-
ported in the Personal Information Management literature, notably [Kelley and Chapanis, 1982,
Payne, 1993, Jones et al., 2005, Marshall and Bly, 2005]. We did not attempt to
test any a priori hypotheses, but were interested in examining how calendar prac-
tices have evolved in the years following previous calendar studies by Kelley and
Chapanis [Kelley and Chapanis, 1982] and Payne [Payne, 1993].
Our study has three components to it: a survey (N=98), in-person interviews
(N=16), and an examination of calendar artifacts such as screenshots and paper
calendars. A large-scale online survey was distributed among members of a uni-
versity. A total of 98 responses were received (54% male and 45% female), includ-
ing faculty (56%), administrative staff (20%), and students (19%) (ﬁgure 1). While
previous studies have examined organizational calendars [Dourish et al., 1993] and
groupware calendar systems [Grudin, 1996, Palen and Grudin, 2003], our focus
was on the personal use of calendars.
Figure 1: Roles of survey participants
In part two, we conducted in-depth personal interviews with 16 participants,
recruited from among the survey participants. The recruitment criterion for inter-
view candidates was the same as in [Kelley and Chapanis, 1982]: that participants
should be regular users of some form of calendar system, either electronic or paper
or a combination of both. Participants included graduate students, faculty mem-
bers, administrative assistants, a department head, the director of a small business,
etc., among others.
Interviews ranged from 20 to 30 minutes each, and were conducted in situ
at their workplaces so we could observe their calendaring practices directly (e.g.
calendar programs or wall calendars or paper scraps.) Interviews were semi-
structured and open-ended: a prepared set of questions was asked in each inter-
view. The questions we asked were closely modeled on those asked in similar stud-
ies [Kelley and Chapanis, 1982, Payne, 1993]. The complete set of questions is
available as an appendix in a technical report [Tungare and P
As an extension to past studies, we were able to explore the use of features of
modern calendar systems such as alarms, reminders, and mobile use, which were
absent in paper calendars. Interviewees were encouraged to talk freely and to ex-
pand upon any of the themes they wished to discuss in more detail. Additional
topics were addressed as appropriate depending on the interviewee’s calendar use.
Examining the calendar systems in use at their desks or on their walls prompted
speciﬁc questions from the interviewers about these practices.
All interviews were transcribed in full. We performed content analysis [Krippendorff, 2004]
of the transcripts to extract common patterns of use. The main purpose of content
analysis in this study was to summarize the ﬁndings into groups of common ob-
servations, as in [Marshall and Bly, 2005]. Individual responses were tagged into
several categories by two of the authors and any differences reconciled by dis-
cussion. Nearly 410 tags resulted from this activity; these were then collapsed into
383 tags (grouping together tags that were near-duplicates) and 11 top-level groups
during the clustering procedure.
From each interview participant, we collected copies of artifacts that were used
for calendaring purposes: 2 weeks’ worth of calendar information and any other
idiosyncratic observations that were spotted by the interviewers. These included
screenshots of their calendar programs, paper calendars, printouts of electronic
calendars (that were already printed for their own use), sticky notes stuck on paper
calendars, etc. Some of these reﬂected a degree of wear and tear that occurred
naturally over time; others provided evidence of manipulations such as color high-
lights, annotations in the margins, or comments made in other ways. Artifacts were
not coded on any particular dimension, but pictures of these artifacts are used to
supplant our textual descriptions wherever appropriate. (See ﬁgures 4, 5 and 8.)
4.1 General Use of Calendars
4.1.1 Capturing and Adding Events
Capturing events refers to the act of knowing about an event and entering it into a
calendaring system (also referred to as the ‘keeping’ phase in the PIM literature.)
Most survey participants reported adding new events as soon as they were (made)
aware of them (93%) while the rest added them before the end of the day. Even
when at their desks, those users who owned PDAs reported using them to create
new events in their calendar: this was deemed faster than trying to start the calendar
program on a computer and then adding an event. When away from their desks,
they used proxy artifacts such as printed calendar copies or paper scraps.
Information about new events reached the primary calendar user via one of sev-
eral means: email, phone, and in-person were commonly reported (ﬁgure 2). The
fact that email was the most common way reported in our study is an expected evo-
lution from older ﬁndings [Kelley and Chapanis, 1982] that phones were the most
common stimuli for calendar events. Interviewees mentioned several other meth-
ods through which they received events: ﬂyers, posters, campus notices, meeting
minutes, public calendars (such as academic schedules or sports events), news-
papers, internet forums, (postal) mail, fax, radio, or scheduled directly by other
people who had access to the calendar (e.g., shared calendars). The wide variety
of sources here is a potential indication of the problem of information overload
[Schick et al., 1990] faced by knowledge workers.
0 20 40 60 80 100
Number of survey participants out of 98
Frequently Sometimes Rarely
Figure 2: How new events arrive in users’ PIM systems
4.1.2 Personal Calendar View Preference
We refer to the most common time interval shown in a calendar program or on a
paper calendar as the preferred personal calendar view: the week view was pre-
ferred by most of our survey participants at 44%, followed by the day view at 35%,
and the month view at 21% (ﬁgure 3). These are very close to the numbers reported
by Kelley et al. [Kelley and Chapanis, 1982] (45%, 33%, 22% respectively).
That many interviewees preferred a week view suggests the use of the calen-
dar for opportunistic rehearsal, because they browsed the entire week’s appoint-
ments each time they viewed the calendar. This preference supports the analysis
of [Payne, 1993] in that the printed versions of calendar do provide a valuable aid
in opportunistic reading of the the week’s activities. Users who kept multiple cal-
endars within the same calendaring system indicated that they turned the visibility
of each calendar on or off on demand, based on the speciﬁcs of what they needed
to know during a particular lookup task. On smaller devices such as PDAs, the
default view was the daily view.
Preferred calendar view
Preferred printed view
Monthly Weekly Daily
Figure 3: Preferred calendar views
There seem to be two motivators for browsing calendars: looking for activi-
ties to attend in the near future, and looking for activities further out that require
preparation. A daily view directly supports the ﬁrst, while a week view partially
supports the second one. Intermediates such as Google Calendar’s 4-day view af-
ford browsing for future events without losing local context for the current day.
The downside of such a view, however, is that days no longer appear in a ﬁxed
column position, but in different locations based on the day. Thus, the preferred
calendar view depends on the type of activity the user is doing.
4.1.3 Frequency of Consulting the Calendar
When asked about the frequency at which users consulted their calendars, we re-
ceived a wide range of responses in the survey: keeping the calendar program
always open (66%) and several times a day (21%) were the most common.
In the interviews, several other speciﬁc times were reported: just before bed-
time or after waking up; only when prompted by an alarm; when scheduling a new
event; once weekly; or on weekends only. Two interviewees reported consulting
their calendar only to check for conﬂicts before scheduling new events, and for
conﬁrmation of events already scheduled.
4.1.4 Proxy Calendar Artifacts
We use the term ‘proxy calendar artifacts’ (or ‘proxies’ in short) to refer to ephemeral
scraps or notes (characterized as micronotes in [Lin et al., 2004]) or printed calen-
dars or electronic means such as email to self that are used for calendaring when
primary calendar systems are unavailable or inaccessible (e.g. when users were
away from their desks or ofﬁces).
Despite the prevalent use of electronic calendars, many were not portable and
were tied to speciﬁc desktop computers. This prompted the users to use other
means to view or add events to their calendar; about 27% reported that they used
proxy artifacts such as scraps or notes to be entered into the primary calendar
at a later time. A wide variety of proxy calendar artifacts was reported in our in-
terviews: paper scraps were by far the most common medium; other techniques in-
cluded carrying laptops solely for the purpose of calendaring, PDAs, voice recorders,
and printouts of electronic calendars. Information captured via these proxies was
transferred to the primary calendar after a delay: most often, users entered the
events as soon as they could access their primary calendar (63% of survey partici-
pants), a few others reported entering them within the same day (25%), while the
maximum delay reported was up to one week.
4.1.5 Information Stored in an Event Record
Calendar systems allow users to add several items of information to an event
record. Typical information included the date of the event (97%), time (96%),
location (93%) and purpose (69%) as indicated in the survey. In interviews, it was
clear that common ﬁelds such as notes, other attendees and status were used only to
a limited extent. Location was entered mostly for non-recurring events. However,
many other pieces of information were frequently recorded, even though calendar
programs do not have a speciﬁc ﬁeld for these data. For example, information
critical for participation at an event was entered inline for easy access: e.g. phone
numbers for conference calls, cooking menus and shopping lists, meeting agenda,
original email for reference, links to relevant web sites, and ﬁlenames of relevant
One participant mentioned adding meeting participants’ email addresses in
case she needed to inform them of a cancellation or rescheduling. For activities
such as trips or ﬂights, further details such as booking codes and ﬂight details were
included as a way of reducing information fragmentation between the calendar
system and the email system.
4.1.6 Types of Events
The events most commonly recorded on calendars by survey participants were
timed events such as appointments or meetings (98%), special events requiring
advance planning, such as tests (93%), long duration events such as the week of
ﬁnal exams at the end of each semester (66%), and all-day events such as birthdays
(81%). Several interviewees also mentioned recording to-do items in a calendar,
such as phone calls to be made, or tasks which would remain on the calendar until
completed, or which were scheduled in on their deadline. Speciﬁcally, we found
several instances of the following types of events scheduled:
• Work-related events. Many interviewees used calendar scheduling for work-
related events such as meetings, deadlines, classes, public events such as
talks and conferences, and work holidays. Users in work environments in-
cluded vacation details for co-workers and subordinates. Time was routinely
blocked off to prepare for other events: e.g. class preparation or ground work
to be done before a meeting.
Interviewees who had administrative assistants reported that their assistant
maintained or co-maintained their calendar (7 out of 16 interviewees). The
dynamics of shared access were vastly different across all these situations.
One interviewee mentioned that he would never let an assistant be their pri-
mary scheduler; the assistant was able to access only a paper copy and any
new events would be reviewed and added by the primary calendar user. Two
other users mentioned that they provided paper calendars to subordinates to
keep track of their schedule and to be able to answer questions about it to
third parties. One participant reported calling in to their secretary when they
needed to consult their schedule while away from their desk (similar to pre-
vious reports in [Perry et al., 2001]), while another reported sending email
to themselves as a way to quickly capture a newly-scheduled meeting.
• Family/personal events. Half of the survey respondents indicated that they
coordinate calendars with their spouses, roommates, or family. Even though
family activities such as picking up kids from school, or attending church
services, were easily remembered without the aid of a calendar, interviewees
reported that they chose to record them anyway to provide “a visual idea of
the entire day” (ﬁgure 4). Public holidays, family birthdays, and guest visits
were added to prevent accidental scheduling of conﬂicting events.
Figure 4: Family events such as attending church are added to calendars, not for re-
membering, but to be able to get a visual idea of the entire day.
Many participants reported having separate calendars for business use and
for home/personal use, as was also seen in a majority of respondents in
[Kelley and Chapanis, 1982]. Although events overlapped between them
(e.g. work trips on family calendars and family medical appointments on
work calendars), the calendars themselves were located at the respective
places and maintained separately. Family calendars were most likely to be
kept in the kitchen, on the refrigerator.
Two contrasts between work calendars and home calendars were promi-
nent: work calendars were more often electronic while home calendars more
likely to be paper calendars, e.g. as a wall calendar, or on the refrigerator.
Work calendars were updated by the primary users or their secretaries or
their colleagues, while family calendars were overwhelmingly managed by
women. No male participant reported being the only calendar manager at
home; women reported either being the only person to edit it, or sharing
responsibilities with their husbands.
Family-related events and reminders were constrained to the home calendar,
as in [Nippert-Eng, 1996], but they were sometimes added to work calendars
if such events would impact work time. For example, medical appointments
(of self or family members) that occurred during work hours were added to
work calendars so that their co-workers were aware of their absence.
• Public events. Public events were added even when the user had no inten-
tion of attending that event. They were added to recommend to other people,
or for personal planning purposes, or to start conversations related to the
public activity. An administrator (from ANONYMIZED, a small university
town with a very popular college football team) said that although he had no
interest in football, he added home games to his calendar to ensure that visit-
ing dignitaries were not invited during a time when all hotels in town would
be booked to capacity. On the other hand, two interviewees considered such
public events as contributing to clutter in their personal calendar, and chose
not to add them.
4.2 Continued Use of Paper Calendars
In his 1993 study [Payne, 1993], Payne reports that the most stable characteristic
he observed was the continued reliance of all but two participants on some kind of
paper calendar. Our ﬁndings are similar: despite most of our users using electronic
calendars, every one of them reported using paper calendars even if not regularly;
12 out of 16 interview participants reported using them regularly.
4.2.1 Reasons for the Continued Use of Paper Calendars
We group the several reasons and examples elicited from our participants into the
following four categories:
• Paper trail. Cancelled events were scratched off the calendar, leaving a
paper trail. Being able to make a distinction between cancelled and never-
scheduled events was cited as an important concern for continuing with pa-
• Opportunistic rehearsal. We found support for the idea of opportunistic
rehearsal [Payne, 1993]. Users cited that wall calendars needed no more than
a glance to read, and provided for quick reference. This also corroborates
Dourish’s argument [Dourish et al., 1993] that the presence of informational
context in paper artifacts such as calendars is an important motivator for
people to continue to use them, even though electronic systems support the
information retrieval task better.
• Annotation. Paper calendars are more amenable to free-form annotation,
as reported earlier [Kelley and Chapanis, 1982], and as the following quotes
from our study illustrate:
“That’s what I call the grafﬁti aspect of it, it’s probably freer by
virtue of being handwritten.”
“There is a lot of that [code and symbols]. Stars and dashes and
circles and headlines, marked and completed.”
Figure 5 shows a printed calendar with a sticky note pasted on it. The event is
about a community potluck dinner. The sticky note complements the sched-
uled appointment with information about the dish the participant plans to
bring to the event. Figure 6 shows a picture of a pumpkin hand-drawn on a
printed calendar to mark Halloween on October 31.
Figure 5: Sticky notes are pasted on paper calendars to remind oneself of the prepara-
tion required for an event.
Figure 6: A hand-drawn pumpkin marks Halloween on October 31.
• Prepopulated events. Participants reported that having holidays or other
event details already printed in commercially-available paper calendars was
an important reason for using them. Calendars distributed by the university
contained details not only of academic deadlines, but also of athletic events
and games; [Kelley and Chapanis, 1982] point to branding issues as well.
Paper calendars were used alongside electronic calendars in either a supple-
mentary or complementary role, as follows:
4.2.2 Printouts of Electronic Calendars
Printouts of electronic calendars played a supplementary role: they were used as
proxies of the master calendar when the master calendar was unavailable. 35%
of survey participants reported printing their calendar. Among those printed, all
views were commonly printed: monthly (43%), weekly (33%) and daily (25%)
(ﬁgure 3). Among those who printed, many printed it monthly, weekly or daily
Preferred calendar view
Preferred printed view
Make changes to
Update a public
Make changes to
Update a public
How often do users ...
Monthly Weekly Daily Never
Figure 7: How often users perform activities related to paper calendars.
Based on our interviews, we found that electronic calendars were printed for
three main reasons:
• Portability. Users carried a printed copy of the master calendar to venues
where collaboration was anticipated, such as a meetings or trips. Even those
who carried laptops and PDAs said that they relied on printed calendars for
• Quick capture. Events were often entered into paper calendars ﬁrst because
of their easy accessibility, and were later transferred back to the digital cal-
endar. 4.1.1 One-third of all interviewees reported making changes to paper
copies of their calendars. Not all these changes were propagated back to the
master calendar, however.
• Sharing a read-only view with associates. Taping a printed calendar to the
outside of ofﬁce doors was common practice, as reported by interviewees.
In one instance, a user provided printed calendars to his subordinates so they
could schedule him for meetings. These events were then screened by him
before being added to the master calendar.
4.2.3 Wall Calendars
Wall calendars typically played a complementary role, and there was little overlap
between the events on a wall calendar and those in an electronic calendar. 70%
of survey participants had a wall calendar in their home or ofﬁce, however only
25% of users actually recorded events on it. Family events such as birthdays,
vacations, and days off were most commonly recorded by interviewees. At home,
wall calendars were located in the kitchen, on the fridge.
4.2.4 Index Cards
An extreme case of ad hoc paper calendar usage reported by one of our intervie-
wees involved index cards, one for each day, that the participant carried in his shirt
pocket when he forgot his PDA. Another interviewee reported exclusively using
index cards for calendar management at their previous job because of their porta-
bility and trustworthiness.
“[...] I get a 3×5 index card so that I can stick it in my pocket without
me losing it. Because if it is put on a little piece of paper, I am sure I
will lose it. But a 3×5 index card, it ﬁts in my pocket, but is big enough
so I would not lose it.”
“I used to just take index cards and keep a little stack [...] clipped
together and keep it in my back pocket. I got my schedule, I have my
daily schedule and each index card was a day so I would write in the
daily events [...]. I could easily carry over events from previous days
because I just move that card. Everybody joked about it but it was
a really useful system.” (edited to remove conversational pauses and
“One for the paper, again, I know if they are going to blow up or not.
This [referring to index cards] I am still waiting for it to explode on
me some day.”
We report this not as a trend, but to illustrate the wide variety in the use of
4.3 Reminders and Alarms
Reminders and alarms are one of the major distinguishing features of modern elec-
tronic calendar systems. A majority of survey participants (63%) reported using
these features. One user reported switching from paper to an online calendar be-
cause “a paper calendar cannot have an alarm feature”. We use the term reminder
to refer to any notiﬁcation of a calendar event, and alarm to refer to the speciﬁc
case of an interruption generated by the calendar system. Based on our interviews,
we classiﬁed reminders into three categories taking into consideration the reasons,
time, number, modalities and intervals of alarms. Before presenting the details of
such a classiﬁcation, however, we examine the individual factors in more detail.
4.3.1 Reasons for Using Alarms
Although reminding oneself of upcoming events is the most obvious use case for
alarms, there were several other situations where users mentioned using reminders
in addition to consulting their calendars regularly. Even when users were cognizant
of upcoming events, they preferred to set alarms to interrupt them and grab their
attention at the appointed hour. Alarms served as preparation reminders for events
that were not necessarily in the immediate future.
When subordinates added events to a primary user’s calendar, alarms were
deemed an important way of notifying that user of such events. Early morning
meeting reminders doubled up as wake-up alarms: one interviewee reported keep-
ing their PDA by their bedside for this purpose. Another interviewee who needed
to move his car out of a university parking lot where towing started at 8:00 am
sharp had set a recurring alarm (ﬁgure 8). In one case, alarms were closely moni-
tored by a user’s secretary: if an event were missed by the user by a few minutes,
the secretary would check on her boss and remind him to attend the meeting that
was now overdue.
Figure 8: One user showed us an example where he set an alarm for moving his car
before a towing deadline set in at 8:00am.
4.3.2 Number and Modalities of Reminders
While most survey participants only set a single reminder per event (52%), many
others reported using multiple alarms. We conclude from our interviews that dif-
ferent semantic meanings were assigned to each such reminder: an alarm one day
before an event was for preparation purposes, while an alarm 15 minutes before an
event was a solicited interruption. Multimodal alarms were not used by many: the
two most popular modalities used individually were audio (40%) and on-screen
4.3.3 Alarm Intervals
Reminders were set for varying intervals of time before the actual events took
place, ranging from 5 minutes to several years. The two factors that affected this
timing were (1) location of the event, and (2) whether or not (and how much)
preparation was required. Users often set multiple alarms to be able to satisfy each
of these requirements, because a single alarm could not satisfy them all. Based on
these ﬁndings, we classify alarms into 3 categories:
• Interruption Reminders. Alarms set 5-15 minutes before an event were
extremely short-term interruptions intended to get users up from their desks.
Even if they knew in their mind that a particular event was coming up, it
was likely that they were involved in their current activity deeply enough to
overlook the event at the precise time it occurred. 15 minutes was the most
common interval, as reported by 8 out of 16 interview participants.
We found that the exact interval for interruption reminders was a function of
the location of the event. Events that occurred in the same building as the
user’s current location had alarms set for between 5 and 15 minutes. Events
in a different building had alarms for between 15 minutes and 30 minutes,
based on the time it would take to reach there. Two interviewees reported
that they set alarms for TV shows and other activities at home for up to 1
hour prior, because that is how long their commute took.
• Preparation Reminders. Users set multiple alarms when preparation was
required for an event: the ﬁrst (or earlier) alarm was to alert them to begin the
preparation, while a later alarm was the interruption reminder for that event.
Payne [Payne, 1993] mentions the prevalence of this tendency as well: the
reason for the ﬁrst alarm (out of several) is to aid prospective remember-
ing where the intention to look up an event is not in response to a speciﬁc
temporal condition, but instead such conditions are checked after the inten-
tion is recalled. If certain items were needed to be taken to such meetings,
preparation reminders were set for the previous night or early morning on
the day of the event. Based on the interviews, preparation reminders were
more commonly used for non-recurring events than for recurring events.
• Long-term Reminders. Events several months or years into the future were
assigned reminders so that the user would not have to remember to consult
the calendar at that time, but instead would have them show up automatically
at (or around) the proper time. This is an illustration of using the calendar for
prospective remembering tasks. Examples include a department head who
put details of faculty coming up for tenure in up to 5 years, and a professor
setting reminders for a conference submission deadline several months later.
4.4 Calendars as a Memory Aid
Calendars serve a value purpose as external memory for events [Payne, 1993]. In
addition, in our data we found that the role that calendars play with respect to
memory goes beyond this simple use. In particular, the following uses of calen-
dars illustrate the different ways in which calendars serve as memory aids beyond
simple lookups: First, users reported recording events in the calendar after the fact,
not for the purpose of reminding, but to support reporting needs. Second, a few
reported using previous years’ calendars as a way to record memorable events to
be remembered in future years. For those that used paper calendars, these events
were often copied at the end of the year to newer calendars. The function of mem-
ory aid goes beyond remembering personal events (appointments and deadlines);
it serves as a life journal, capturing events year after year. Kelley and Chapanis
[Kelley and Chapanis, 1982] reported that 9 out of 11 respondents in their study
kept calendars from two to 15 years.
4.4.1 Reporting Purposes
In our study, 10 out of 16 interviewees reported that they used their calendar to
generate annual reports every year. Since it contained an accurate log of all their
activities that year, it was the closest to a complete record of all accomplishments
for that year. Among these, 5 users reported that they archived their calendars year
after year to serve as a reference for years later. This tendency has also been re-
ported in past studies [Kelley and Chapanis, 1982, Payne, 1993]; Kelley referred
to it as an ‘audit trail’, and highlighted the role of calendars in reporting and plan-
One person mentioned that they discovered their father’s journal a few years
after his death, and now they cultivate their calendar as a memento to be shared
with their kids in the future.
“I think I occasionally even think about my kids. Because I do, I save
them, I don’t throw them away [...] I think that it’s common with a
little more sense of mortality or something. It’s trying to moving things
5 Opportunities for Design
In this section, we highlight how some of our ﬁndings can be address through new
electronic calendar designs.
5.1 Paper Calendars and Printing
We do not believe that paper calendars will disappear from use; they serve several
useful functions that are hard to replace by technology. Electronic calendars in
general are more feature-rich than paper calendars. Portable devices have good
support for capturing information while mobile. Yet, we found that paper calendars
and proxies continue to be prevalent in the use of calendar management. They
provide support for easy capture of calendar information, are effective at sharing,
and support the display of the calendar in public view with ease.
Therefore, given the many uses of paper calendars, we consider how electronic
calendar systems can provide better support for these proxies. Richer printing ca-
pabilities might provide easy support for transferring online calendar information
to the paper domain. Printing a wall calendar is a novelty relegated to specialized
design software. However our ﬁndings show that wall calendars play a signiﬁcant
role in supporting calendar management, particularly at home. With affordable
printing technology available, it is possible to print a wall calendar or table calen-
dar at home, incorporating not only details of events from a user’s personal elec-
tronic calendar, but also visual elements such as color coding, digital photos (for
birthdays, etc.) and event icons. In a way, printed calendars are used in similar
ways as discussed in [Lin et al., 2004].
5.2 Digital Paper Trails
Some of the features of paper calendars can be recreated in online systems. For
example, current electronic calendar systems remove all traces of an event upon
cancellation, without providing an option to retain this historical record. This was
one of the shortcomings which led interview participants to rely on paper instead.
Instead of deleting events, they could be faded out of view, and made visible upon
request. Most calendar software support the notion of different calendars inside of
the same program. A possibility is that all deleted events could simply be moved
to a separate calendar, where events can be hidden easily. Yet, the events would
remain in the calendar as a record of cancelled activity.
5.3 Tentative Event Scheduling
Several participants indicated that they ‘penciled in’ appointments in their pa-
per calendars as tentative appointments to be conﬁrmed later (also identiﬁed as
a problem in [Kelley and Chapanis, 1982]). These tentative appointments served
as a way of blocking particular date/time combinations while a meeting was being
scheduled with others. Often, there were several of these tentative times for a par-
ticular meeting. Once the meeting was conﬁrmed, only one of them was kept and
the rest discarded. This type of activity is not well-supported in personal calendars.
For corporate calendars, there is adequate support for scheduling group meetings,
but it is often missing in personal calendars.
5.4 Intelligent Alarms
Calendar alarms and reminders have evolved from past systems and now allow
notiﬁcation in several ways: audible alarms, short text messages, popup reminders,
and email are just a few. However, the fundamental concept of an alarm still tailors
only to interruption reminders.
• Preparation reminders. To support preparation reminders, many electronic
calendars allow the creation of multiple alarms per event, with different
modalities for each (e.g., email, SMS, sounds, dialog box). However, when
these reminders are used for preparation, as we found in the study, users of-
ten wanted to have more context: they expected to have an optional text note
to indicate what preparation was required. E.g., alarms that would remind
a user before leaving home to remember to carry material for an upcoming
meeting, or a reminder the previous night to review documents.
• Location-related alarms. The location of events was found to be an impor-
tant inﬂuencer of alarm time. If calendars supported the notion of location
(besides simply providing a ﬁeld to type it in), alarms could be automatically
set based on how long it would take the user to reach the event.
• Alarms on multiple devices. When an alarm is set on multiple devices, each
will go off at the exact same time without any knowledge of all the others.
There is need to establish communication among the devices to present a
single alarm to the user on the mutually-determined dominant device at the
5.5 Supporting a Rich Variety of Event Types
Users reported that not all events were equal: public events were merely for aware-
ness, recurring events indicated that time was blocked out, and holidays were
added to prevent accidental scheduling. From the users’ point of view, each has
different connotations, different visibility (public events should ideally fade out of
sight when not required), and different types, number and intervals of alarms.
• Event templates. A calendar system that supports event types can provide
ways and means for users to create event templates and categories with dif-
ferent default settings along each of the dimensions outlined above. By hav-
ing event templates, quick capture is supported as well. When much of the
extra information about an event is pre-ﬁlled, data entry can be minimized
to just the title of the event. Certain types of events have special metadata
ﬁelds associated with them, e.g. conference call events contain the dial code,
ﬂight events contain airline and arrival/departure info. This could be easily
achieved by event templates.
• Showing/hiding public events. While a few users said they added public
events for informational purposes, others did not want public events (that
they would not necessarily attend) to clutter their calendar. If calendars sup-
ported making certain event types visible or invisible on demand, the needs
of both user groups could be met. Again, by providing an option to keep
all events in the same calendar, such a system would contribute to reducing
5.6 Reporting and Archival Support
Report generation is a signiﬁcant use of electronic calendars. Calendar software
should have a way to generate reports and export information so that particular
groups of events can be summarized in terms of when the meetings/events oc-
curred, how many hours were devoted to them, and capture any notes entered in
the calendar. One participant reported that he uses the search functionality in his
calendar to obtain a listing of events related to a theme. This is used to get an
idea of the number of hours devoted to particular activities and help to prepare an
annual activity report.
6 Discussion & Future Work
The paradox of encoding and remembering, as described in [Payne, 1993], was
clearly evident in our data. Participants seem to over-rely on calendar artifacts
to remember appointments, as seen in the setting of multiple alarms, printing of
calendars for meetings, carrying a PDA everywhere, and calling their secretary to
conﬁrm events. The unfortunate side effect of sharing the management of a calen-
dar with other people is that the primary user no longer goes through the personal
encoding episode of entering the information. Some participants relied on admin-
istrative assistants to enter events in their calendars. At home, many participants
relied on their spouses to maintain the calendar. Some participants even suggested
the need to have an alarm for when events were added to their calendars. All of
this points to a diminished opportunity for encoding the information that is entered
into one’s calendar. This makes it very difﬁcult for participants to remember what
is in their calendar, given that at times the scheduled events have never been seen
before they occur.
On the other hand, the opportunity for rehearsal is greater today, if users take
advantage of existing information dissemination and syndication techniques. For
example, keeping a calendar on a desktop computer and publishing to an online
calendar service such Google Calendar or Apple Mobile Me makes the calendar
available in many other locations. Users can view their calendar on the web from
any web browser, from mobile phones, or in the background on a desktop com-
puter as part of widgets (tiny applications) such as Apple’s Dashboard or Google
Gadgets, or access it over a regular phone call [P
nones and Rode, 2004].
So, the possibility of opportunistic rehearsal is afforded by current systems. We
did not observe this in our data, as many of our users did not use these services.
However, the paradox of encoding, rehearsal, and recall seems to be in need of
future work so we can understand the impact of electronic calendar systems on
7.1 Survey Questions
• Occupation (Undergraduate Student, Graduate Student, Faculty, Staff, In-
• What is your age group?
7.1.2 Calendar Use Basics
• Which devices do you own or use frequently?
• What computing-enabled calendars do you use?
• Do you use your computer to keep your calendar? If so, which program
do you use for your main calendar management task on your desktop/laptop
• If you own and/or use a PDA, which calendar program do you use on the
• Do you use an online calendar?
• What events do you record on your calendar?
• How often do you visit your calendar?
• How far ahead do you regularly look when you view your calendar?
• What would you consider your preferred view?
• If your calendar software includes a To-Do function, do you use it?
• Does your calendar software have a way to classify calendar events by cate-
gories? If so, how do you use this feature?
• Who changes and updates your calendar?
• How often do you add new events?
• Do you keep ‘proxies’ (for example, post-its) or other notes that need to be
entered in the calendar at a later time?
• How long does it take for the proxy to make it into your main calendar?
7.1.3 New Events
• How frequently do you get events by phone (someone calls you) that go into
• How frequently do you get events by e-mail (someone sends you email) that
go into your calendar?
• How frequently do you get events in person (someone tells you of a meeting)
that go into your calendar?
• By what other methods do new events arrive?
7.1.4 More Calendar Use
• What kinds of calendar failure (e.g. missed an event due to not entering it in
calendar, scheduled conﬂicting events) have you experienced?
• What do you store in the calendar entry (check all that apply)?
• What other information do you record in your calendar?
• Do you use the alarms options of your calendar software?
• If you do use them, how much advance warning do you set your alarms for?
• If you do not use them, why not?
• If you are setting an alarm for an event, how many alarm notiﬁcation do you
• What medium of notiﬁcation do you use for your alarms?
• Please explain the role of an alarm?
7.1.5 Use of PDAs
• Do you synchronize your PDA calendar with a desktop calendar?
• If so, how often?
• Which do you consider the ‘master’ or main calendar?
• Do you make changes only on the desktop, thus keeping your PDA as a
• When you are at your desk, which device do you use to look up events?
• When you are at your desk, which device do you use to enter new events or
change existing ones?
7.1.6 Use of Paper Calendar Products
• Do you print your calendar?
• Which view do you print most frequently?
• How often do you print any of your views?
• Do you make changes (or write notes) in the printed copy?
• How often do you copy changes back to your computer?
7.1.7 Use of a Wall Calendar
• Do you have a wall calendar in your home or ofﬁce?
• If so, do you mark events there?
• If so, what types of events do you put on your wall-calendar?
• Do you copy these events to your ‘main’ computerized calendar?
7.1.8 Public Display of Calendar Information
• Do you keep a publicly available calendar (like posted ofﬁce hours on your
door, or in the department web page)?
• If so, how often do you update it?
• If you keep an online calendar, what privacy settings do you use?
7.1.9 Sharing of Calendar
• Do you share your calendar with others?
• If so, with whom?
• Do you coordinate calendar events with your spouse, roommate, family?
7.1.10 Phone Access to Calendar
• Do you use a service that provides access to your calendar over the phone?
• Would you like to use such a service?
7.2 Interview Questions
• How important is your calendar to your work/daily activities?
• If you use multiple calendar systems, how often do you sync them? On
a regular basis i.e.: every morning when you arrive at work, or as events
• If you use multiple calendar systems, do you go back and forth between them
during the day? Which do you use when and why?
• Do you use a to-do list?
• What events are on the to-do list versus scheduled as an event on the cal-
endar? I.e.: presentation for a meeting are a to-do or is the meeting just
scheduled on the calendar with a note in the entry that a presentation is due
at that time?
• Do you keep “proxies” (sticky notes) or other notes that need to be entered
in the calendar at a later time?
• What situations arise that make it necessary to use these proxies?
• Do you record public events on your calendar? (e.g. beginning of the
Olympic games, holidays, election days, football dates, etc.)?
• What is your reasoning behind recording these public events?
• If you use alarms, what is the role of the warning? (i.e.: warning for a timed
event or an appointment (such as History, 1-2pm Friday), warning to prepare
or plan for an event, appointment, or deadline (such as History Test Friday),
period events (Olympic games in session, football weekend))?
• Have you experienced any calendar failures? What kinds of calendar failures
have you experienced? Please elaborate.
• Do you print your calendar? If so, do you change the printed copy?
• What are your reasons for making changes in the printed copy?
• Do you copy these changes back into your electronic calendar at any point?
• How long do you use this printed copy before printing out an updated one?
• Do you keep more than one calendar? (A wall calendar or other paper, com-
• What criteria separates what goes on one or the other?
• Is there any overlap? Is one just a pared-down version of the other one or do
they contain completely separate events?
• Do you coordinate calendar events with your spouse, roommate, family?
• If so, how do you go about doing that?
• Please explain any additional ways in which you use your calendar system.
• What are you habits as far as when you look at your calendar, how often, how
far ahead do you look, how in-depth you examine events when you look, etc.
• Do you use a method of organization on a paper calendar that you cannot
apply to an electronic calendar? (i.e.: speciﬁc types of events go into a
speciﬁc area of the date box, highlighted events, etc)
• Is there anything else about your personal information management we have
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their participation. We would also like to acknowledge Kyunghui Oh for assistance
with preliminary analysis of the data collected, and Leysia Palen and Pardha Pyla
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