When someone describes a person as a “messy” or “tidy”, we can instantly guess something about their appearance, their personality, and the way they organize their physical and digital artifacts – around the house, office, or on their computer(s). There is little disagreement around these definitions, and many stereotypes (both positive and negative) are commonly associated with each. Messiness is often associated with artistic, creative and scientific or mathematical genius, spontaneity, but also with carelessness, eccentricity, madness and unreliability. Neatness is associated with preparedness, confidence, attention to self-presentation, efficiency, and stability, but also with hierarchy, rigidity and mundanity .
Famous examples of each personality type abound. In the messy camp, Albert Einstein, Francis Bacon, Alexander Fleming, and Alan Turing were all notoriously messy geniuses whose unkempt appearances matched their chaotic laboratories and studios. Meanwhile, David Beckham, the English footballer, and Martha Stewart, both notorious neat freaks, could stand for the personification of Confidence and Pristine Order respectively.
But from where are such tendencies derived? Is it evolutionary, cognitive, or occupational? That is, are people born tidier or messier than others, do they grow into it as they develop, or do they adapt based on the demands of their roles, jobs or environments? What drives people to be messy or tidy? Is there scientific basis showing that it is better to be one or the other? Why does “messiness” or “tidiness” in one aspect of our lives tend to correlate strongly with messiness or tidiness in others ?
More relevant to the discussion of Personal Information Management tools, what does an individual’s personal organizational messiness shape the way they keep and manage information? More importantly, what does it imply towards the design of new tools that could better support people’s needs? Should digital PIM tools be made to facilitate the unique needs of tidy and messy people, or should they try to shape people into one or the other?
Why are people messy?
The simplest theory is that messy individuals perceive the cost of tidying to be less than the potential benefits. (We all probably know one or two computer scientists that use this as an excuse!) If only the benefit gained in facilitating later retrieval is meaured, this is true in many cases; a quantitative analysis of e-mail use has shown that, constantly foldering e-mail is a waste of effort due to the infrequency with these messages are actually ever later needed (compounded by the availability of search tools, which we discuss later). But tidying has other additional benefits mentioned below.
A second theory is more attentional: that messy people are perpetually distracted with things that are “more interesting” or important than tidying up. This is a subconscious choice that happens instinctively, as things grab their attention: “as soon as we have finished with the coffee cup, it is invisible to us. We simply don’t see it. It’s like that stage of a baby’s development at which, if something leaves its grasp, it ceases to exist” [Abrahamson]
A third theory points to innate cognitive reasons: tidy people might think more hierarchically or categorically than messy people. From “The Etiology of Messes” (Abrahamson, 2002):
Simon (1962) raises the possibility that hierarchically-structured systems only appear to be ubiquitous because the human cognitive apparatus is itself a hierarchical-ordered categorization scheme (Rosch, 1978). Such hierarchical categorization schemes allow us to parse out, encode, reason with, and remember hierarchical-ordered information, causing us to perceive hierarchies as ubiquitous in natural, social, and symbolic systems. These schemes might also obscure alternate, non- hierarchical forms of order, revealing them as the deviations from order, which can to them be perceived of as messes. 
Thus to those who are hierarchical thinkers, anything other than a hierarchy might be perceived a mess, and those that are messy are merely non-hierarchical (e.g., relational) thinkers.
Why are people tidy?
For tidy people, however, the aesthetic or emotional value of maintaining their system makes it worthwhile to dedicate time and attention towards maintaining it. Those who appreciate order and neatness see it as an essential part of dealing with the complexities of the world; as summarized by Martha Stewart, “Life is too complicated not to be orderly.”
There are well-known advantages to order and organization. Hierarchy has been used in ages to combat complexity and build up resilience to failure, disruptions and interruptions. Complex human-designed systems, from organizations to computer software programs are organized hierarchically so that the roles and relations among parts are clear, and communication is restricted to those with whom contact matters most. Hierarchical organization is easy because a linear number of steps is needed to pinpoint the location within a comparatively exponential number of items.
Beyond making it easier to get at things by reducing the entropy of collections, the act of tidying serves a number of important purposes for those that are neat-inclined, including reducing stress, producing a feeling of “in-controlness”, making one feel more situationally-aware. In addition, the process of tidying itself involves processes often referred to as external cognition, which can bring insight and understanding — categorical formation, refinement. prioritization and sense-making. The mere act of serendipitous (re-)discovery of an item or information during tidying may help one remember or realizing something important that would have otherwise been forgotten.
What does this mean for Personal Information Management?
Studies in the field of Personal Information Management over the past two decades have repeatedly revealed tidy vs messy differences in the ways that different people organize their information digitally and on paper, including how paper is organized in people’s offices, e-mail, digital calendars, to-do lists, and computer filesystems.   Despite these insights, a long question which has not been answered is how to support such differences in personality — how and whether tools should be made to support messy individuals in their piling practices or to encourage them to be more tidy, for example, or to help tidy individuals, who naturally are already organized, to keep organized. These studies have revealed, however, that the reality is that most people are somewhere between the two extremes; either messy in some ways and neat in others, or alternating between messy and neat over time through periodic tidying. This, unfortunately makes the problem of PIM tool design even more difficult as it becomes less clear how and when to support these tendencies.
One way forward is to look beyond these tendencies and instead at the ways these strategies impact how the individual creates, manipulates, and manages their information. For example, messy individuals deal with new items by, not dealing with them at all (i.e., leaving things where they land),. This suggests that tools might support users who wish to spend little or no time or effort in dealing with new things, such as through low-cost or instantaneous “capture” of new information without categoriation. Tidy individuals, meanwhile, try to organize information as it arrives, but get sometimes overwhelmed (whch causes them to “sweep up” afterwards). This might suggests that tools might proactively support such “queueing up” and prioritization of backlogged items so that tidy individuals can gracefully defer and deal with bursts with ease. Examining the structures that tidy people use to organize (flat, hierarchical or otherwise) should lend significant insight towards what sort of categorization/organization these systems should support.
We will examine our experiments with supporting such needs in a later post.
 Abrahamson, E. ”Disorganization Theory and Disorganizational Behavior:Towards an Etiology of Messes”, Research in Organizational Behavior, Volume 24, 2002, Pages 139-180, ISSN 0191-3085, DOI: 10.1016/S0191-3085(02)24005-8.
 Barrowclife, M. “Messy? I’m an artist!”, The Times Online, Jan 29, 2009.
 Malone, T. W. 1983. How do people organize their desks?: Implications for the design of office information systems. ACM Trans. Inf. Syst. 1, 1 (Jan. 1983), 99-112. DOI= http://doi.acm.org/10.1145/357423.357430
 Whittaker, S. and Hirschberg, J. 2001. The character, value, and management of personal paper archives. ACM Trans. Comput.-Hum. Interact. 8, 2 (Jun. 2001), 150-170. DOI= http://doi.acm.org/10.1145/376929.376932