An Analysis of Author-Specific Email Signature
A Case Study
October 21, 1998
One day, my friend Mohit wrote a letter to our lab's mailing list, wondering why some people sign their email with a dash in front of their names, and others don't.
I was in a silly mood and had a couple of extra hours on my hands...
From: Jeremy Elson
To: Mohit Talwar cc: firstname.lastname@example.org Subject: Re: wondering In-Reply-To: Message from Mohit Talwar of "Wed, 21 Oct 1998 13:14:45 PDT." Date: Wed, 21 Oct 1998 18:01:53 -0700 Mohit Talwar writes: >why people (a lot of them) sign their emails as > >'- name' > >I mean, why the '-' ? Mohit: Thank you for your interesting and thought-provoking question. It has spurred me on to doing extensive research on this topic from my email archives, the results of which I present below. Although my research does not directly answer your question ("why the '-'?"), I think it does shed some interesting light on that question, as well as quantifying to some degree your guess of "(a lot of them)". I would like to discuss these results in Dgroup very soon so that I can make the submission deadline for ACM SIGSIG '99 (the ACM Special Interest Group on Signatures). (by the way, in case it is not clear -- this is only meant to make you laugh, it is NOT SERIOUS!!! :) ) ------------------------------------------------------------------------ Analysis of Author-Specific Email Signature Styles: A Case Study J. Elson, University of Southern California ABSTRACT Email lives in an interesting space halfway in-between informal conversation and formal written communication. There are many stylistic components of an email that are typically not characteristic of traditional written correspondences: for example, capitalization, spell-checking, position of quoted material, and other factors. One of the most interesting and illuminating is the way in which email authors sign their names. A number of different styles are presented, and their significance discussed. We conclude that while styles differ radically across authors, an individual typically uses a consistent style. INTRODUCTION Email has become the primary means of communication in many academic and technical environments. As users' familiarity with email increases, elements of their personalities become incorporated into the way in which their email is written. These styles vary in a large number of dimensions: the selection of a subject, the style of the greeting, the capitalization conventions used, the rigor of spell checking, inter-sentence and inter-paragraph spacing, the form of the signature, and a wide variety of other features that are not necessarily consistent from author to author. Our research initially focused only on the signature; other aspects of email were beyond the scope of our current interest but are an area of active research. Our analysis of email signature styles has indicated that email signatures do not follow an "ad hoc" pattern as has previously been suggested. Rather, it is possible to classify them in a way that exposes an underlying structure. It is also interesting to note that signature style variability is quite low when analyzing the set of emails written by a single author. Our classification system is presented in the next section. Section 3 presents our analysis of the most popular forms of signatures. Section 4 describes our conclusions. A TAXONOMY OF EMAIL SIGNATURE STYLES A signature can initially be broken down into two distinct components. Consider the following example: regards, jeremy This paper will define the "salutation" to be the generic word that signifies the imminent end of the email. In this example, "regards" is the salutation. The second component we will define is the "personal identifier" (abbreviated PI), which is a series of characters that identify the author of the email. In the example above, "jeremy" is the PI. A wide variety of signature styles were observed in traffic from the "dphds" mailing list in the time period of this study (August 26-October 21, 1998). The signatures in our study varied both in their salutations and PIs. Our first analysis revealed that there were an unacceptably large number of distinct styles when both the salutation and PI were considered; allowing both to vary results in a combinatoric explosion of possible email signatures. Therefore, only the PI was considered; the salutation will be ignored for the remainder of this paper. Although the number of PI styles at first seemed to be large, patterns soon began to emerge which lead to a classification system. Our classification system is shown in Figure 1, along with a number of sample email signatures taken from the sample group to illustrate some of the classes. |Capitalized | | |First Initial Only (not full name) | | | | |Pre-Name Characters | | | | | | |Post-Name Characters Reference Example | | | | ----------------------------------------------------------------------------- [DEB98] D. x x x [AHM98] -A x x x [NIR98] Nirupama. x x [PAV98] Pavlin x [GRA98] --Graham x x [ANO98] -Anoop. x x x [JER98a] j. x x [JER98b] j x [YIN98] -ying x [MOH98] mohit. x [AMI98] amit Figure 1: Email Signature Taxonomy with Examples Unfortunately, this classification system is not sufficiently descriptive to capture all possible PI styles. For example, the PI "- Haobo" of [HAO98], the "--Graham" of [GRA98], and the "-Polly" of [POL98], while clearly different, are considered equivalent because our classification does not distinguish between types and numbers of pre-name characters. Also, the fascinating example of "ReZa" [REZ98], a distinctive style contained only in the writings of R. Rejaishushtari, does not fall neatly into our system in a way that distinguishes it from others that are not like it. Although this clearly does a disservice to the flair exhibited by the author, a more complex classification system that did capture such aspects of a style led to poorer statistical analyses. Another variation not easily described by our system is the style of simply not using a Personal Identifier at all. This is style is commonly used in the most informal emails; or, when the author relies on a ".signature" file to provide the distinctive flair that a signature often provides. (It should be noted that adding "a personal touch" is often a signature's only function, as the identification of the author is typically performed by the email header). The email of D. Estrin, for example, is most frequently ended without a PI; the example given by [DEB98], while included in Figure 1 to provide a more complete view of our taxonomy, is not typical for that author. This might lead us naturally to the question: do authors remain consistent in their use of email signatures? This question is an area of future research. TAXONOMY-BASED STATISTICAL ANALYSIS 198 messages representing 24 different authors were collected from the "dphds" mailing list during the period of this study. The raw data are listed in Appendix A. Analysis of the frequency of different signature types is somewhat complicated by the appearance of a large number of null signatures (71, or 35.8%). A null signature can either be considered a valid signature consisting of no characters, or can alternately be considered a non-signature and inappropriate for inclusion in these statistics. Therefore, frequencies will be reported using both interpretations. The first question that drew our attention (and, indeed, was the instigator of the study) was the frequency of use of pre-name characters. In our sample, 69 signatures appeared with pre-name characters -- 54.3% of non-null signatures, and 34.8% of all signatures. Authors seem to remain remarkably consistent with their choice of the use of pre-name characters. Of the authors who used non-null signatures, 9 (42.8%) used "-" exclusively; 10 (47.6%) used no "-" exclusively, and 2 authors (9.5%) are recorded as having used both "-" and no "-" in separate non-null-signed emails. It is interesting to note that, while the analysis based on the number of signatures collected revealed a larger number of signatures containing a leading "-", an author-centric analysis showed a smaller number of authors who consistently prefer this style. This suggests that "-"-using authors are more prolific writers. The use of "-" does not appear to correlate with any of the other three classification types that we previously defined. For example, of the 69 signatures that used a "-", 10 (14.5%) did not use an initial capital letter; similarly, of the 58 non-"-" (and non-null) signatures, 9 (15.5%) did not use an initial capital letter. An analysis of the correlation between the use of an initial "-" and the other two classified types of signatures could not be performed before the expiration of this project's DARPA funding. This is an area of future research. CONCLUSIONS The use of an initial "-" before the personal identifier part of an individual's signature is a popular style. Although representing only 42.8% of authors, emails signed with a leading "-" account for 54.3% of non-null signatures. This suggests that, of authors who choose to sign their names, those who sign with "-" write more email than those who do not. The use of "-" appears not to correlate with other aspects of a signature's style. It is also concluded that the time spent to conduct the research could have been better spent by the author taking a walk on a beautiful day. This is an area of future research. FUTURE WORK There are a number of interesting research questions whose answers might serve to further illuminate the culture of email, but were beyond the scope of our initial research. For example, it would be interesting to note the variability of signature use for a single author. Most authors do have a preferred signature that is most commonly used, but the exact frequency of deviation from that signature for the average author has not yet been determined. Such a study might lead to the use of email signatures as a potential (though admittedly weak) authentication mechanism. Email that is not signed in a manner consistent with the author might be suspected of being a forgery. A number of other future research directions have been proposed, including an analysis of the "thankful imperative" style, e.g. a request for some action signed by "Thanks!!", suggesting that the request is urgent and requires immediate attention. (Initially suggested by Dr. L. Girod.) ACKNOWLEDGMENTS The email archives used in this study were available in part due to computational resources made possible by an NSF Small-Scale Infrastructure Grant, award number CDA-9216321. Dr. M. Talwar originally suggested these research directions. Additional thanks go to Dr. L. Girod and Dr. P.I. Radoslavov for useful discussions and reviews of early drafts of this manuscript, and Dr. D. Estrin for the creation of the mailing list which formed the centerpiece of this study. REFERENCES [AHM98] Ahmed A-G Helmy, "micronets", 14 Oct 1998, 11:40:10 PDT [AMI98] Amit Kumar, "About connection speeds of a modem", 22 Sep 1998, 19:32:51 PDT [ANO98] Anoop Reddy, "Re: who is on this week?", 12 Oct 1998, 9:54:20 PDT [DEB98] Deborah Estrin, "Re: Dgroup wed 9th (fwd)", 8 Sep 1998, 10:50:41 PDT [GRA98] Graham Phillips, "Re: egcs", 20 Oct 1998, 11:20:12 PDT [HAO98] Haobo Yu, "mbone tomorrow", 20 Oct 1998, 15:01:03 PDT [JER98a] Jeremy Elson, "Security slides available on the web", 16 Oct 1998, 16:18:57 PDT [JER98b] Jeremy Elson, "homework 1 turned in today", 20 Oct 1998, 16:23:21 PDT [MOH98] Mohit Talwar, "vern paxon's lecture", 3 Oct 1998, 14:12:18 PDT [NIR98] Nirupama Bulusu, "wednesday talk", 19 Oct 1998, 17:36:52 PDT [PAV98] Pavlin Ivanov Radoslavov, "Re: egcs", 21 Oct 1998, 11:10:54 PDT [POL98] Polly Huang, "Re: Memory exceeded", 19 Oct 1998, 10:21:11 PDT [REZ98] Reza Rejaishushtari, "Re: Memory exceeded", 19 Oct 1998, 10:16:39 PDT [YIN98] Ying Liu, "Re: dgroup", 21 Oct 1998, 10:00:39 PDT APPENDIX A: Signature Frequencies 18 - Haobo 1 - Lew 2 - haobo 19 --Graham 10 -A 1 -Ahmed 2 -Anoop. 4 -Polly 1 -Puneet. 1 -Ya 1 -Ying 1 -Ying Liu 1 -amit 6 -ying 1 -ying liu 1 Cengiz 4 Chalermek 2 D. 1 Eddie 2 Niru 1 Niru. 1 Nirupama. 27 Pavlin 6 ReZa 2 Satish 2 Ya 1 amit 2 art mena 6 mohit. 50 (D. Estrin) 21 (Other authors)
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Original humor by Jeremy Elson, written on October 21, 1998