Relationships among category semantics, perceptions of term utility, and term length and order in a social content creation system.
ABSTRACT While there are increased efforts to extend existing controlled vocabularies through harvesting socially created image metadata from content creation communities (e.g., Flickr), questions remain about the quality and reuse value of this metadata. Data from a controlled experiment was used to examine relationships among categories of image tags, tag assignment order, and users' perception of usefulness of preassigned image index terms. Preliminary findings indicate that, on average, "Group" category terms were assigned first, and were also rated highest in usefulness. Other broad tag categories that were assigned earlier and rated more useful were Human Attributes and People, but others were more variable. However, the study found no correlation between tag length and assignment order, or term length and its perceived usefulness. The study's findings can inform the design of controlled vocabularies, indexing processes, and retrieval systems for images.
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ABSTRACT: There is at present a dearth of information on the everyday image information behavior of ordinary people. Analysis of a set of 64 image-related searches provides insight into potentially useful facilities for an image digital libraryACM/IEEE Joint Conference on Digital Libraries, JCDL 2006, Chapel Hill, NC, USA, June 11-15, 2006, Proceedings; 01/2006
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ABSTRACT: There have been ample suggestions in the literature that terms added to documents from Flickr and Wikipedia can complement traditional methods of indexing and controlled vocabularies. At the same time, adding new metadata to existing metadata objects may not always add value to those objects. This research examines the potential added value of using user-contributed ("social") terms from Flickr and the English Wikipedia in image indexing compared with using two expert-created controlled vocabularies— the Thesaurus for Graphic Materials and the Library of Congress Subject Headings. Our experiments confirmed that the social terms did provide added value relative to terms from the controlled vocabularies. The median rating for the usefulness of social terms was significantly higher than the baseline rating but was lower than the ratings for the terms from the Thesaurus for Graphic Materials and the Library of Congress Subject Headings. Furthermore, complementing the controlled vocabulary terms with social terms more than doubled the average coverage of participants' terms for a photograph. The study also investigated the relationships between user demographics and users' perceptions of the value of terms, as well as the relationships between user demographics and indexing quality, as measured by the number of terms participants assigned to a photograph. It was found that the participants with more tagging and indexing experience assigned a greater number of tags than did the other participants.Library & Information Science Research - LIBR INFORM SCI RES. 01/2012; 34(2).
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ABSTRACT: There is growing interest in, and an increasing number of attempts by, traditional information providers to engage social content creation and sharing communities in creating and enhancing the metadata of their photo collections to make the collections more accessible and visible. To enable and guide effective metadata creation, however, it is essential to understand the structure and patterns of the activities of the community around the photographs, resources used, and scale and quality of the socially created metadata relative to the metadata and knowledge already encoded in existing knowledge organization systems. This article presents an analysis of Flickr member discussions around the photographs of the Library of Congress photostream in Flickr. The article also reports on an analysis of the intrinsic and relational quality of the photostream tags relative to two knowledge organization systems: the Thesaurus for Graphic Materials and the Library of Congress Subject Headings. Thirty seven percent of the original tag set and 15.3% of the preprocessed set (after the removal of tags with fewer than three characters and URLs) were invalid or misspelled terms. Nouns, named entity terms, and complex terms constituted approximately 77% of the preprocessed set. More than a half of the photostream tags were not found in the TGM and LCSH, and more than a quarter of those terms were regular nouns and noun phrases. This suggests that these terms could be complimentary to more traditional methods of indexing using controlled vocabularies.JASIST. 01/2010; 61:2477-2489.
Relationships among Category Semantics, Perceptions of
Term Utility, and Term Length and Order in a Social
Content Creation System
Corinne Jörgensen Besiki Stvilia
College of Communication and Information, Florida State University, PO Box 3062100, Tallahassee, FL 32306-2100
While there are increased efforts to extend existing controlled
vocabularies through harvesting socially created image metadata
from content creation communities (e.g., Flickr), questions remain
about the quality and reuse value of this metadata. Data from a
controlled experiment was used to examine relationships among
categories of image tags, tag assignment order, and users’
perception of usefulness of preassigned image index terms.
Preliminary findings indicate that, on average, “Group” category
terms were assigned first, and were also rated highest in
usefulness. Other broad tag categories that were assigned earlier
and rated more useful were Human Attributes and People, but
others were more variable. However, the study found no
correlation between tag length and assignment order, or term
length and its perceived usefulness. The study’s findings can
inform the design of controlled vocabularies, indexing processes,
and retrieval systems for images.
Categories and Subject Descriptors
H.3.1 [Information Storage and Retrieval]: Content Analysis
and Indexing – indexing methods, thesaurus.
Measurement, Documentation, Experimentation, Human Factors,
Image indexing, Knowledge Organization, Folksonomies, Social
tagging, Metadata, Experimental design.
There has been a large body of research suggesting that socially
created metadata (e.g., user-generated
complementary to traditional knowledge organization systems [6,
7, 8, 10, 11, 12, 13]. This has been accompanied by an increase in
efforts to harvest metadata for image or photo collections to
extend existing controlled vocabularies by deploying these
collections in social content creation communities (e.g., Flickr).
However, different types of users create social metadata in
different contexts and for different purposes [2, 10]. The terms
that users select to search for images may differ from those they
tags) could be
use to describe images . The usefulness and quality of metadata
is recognized as contextual [3, 9]. Furthermore, the construction
of high-quality knowledge organization systems requires
expensive knowledge engineering work. Adding new metadata
may not necessarily lead to value increase or cost reduction for
the activity . Questions remain about the quality and reuse
value of social metadata for image indexing. In particular, it is
essential to determine what terms are useful to the user and how
to identify useful terms for a particular image inexpensively – that
This study examines relationships among categories of image
tags, tag assignment order, and users’ perception of usefulness of
tags. The findings of this study can inform the design of
controlled vocabularies, indexing processes, and retrieval systems
for images. In particular, the findings of the study can advance the
understanding of image tagging practices, tag facet/category
distributions, relative usefulness and importance of these
categories to the user, and inexpensive mechanisms for
identifying important terms.
This study examines the following research questions:
What is the relationship between the categories of tags users
assign to images and the tag assignment order? (Free tagging
– Description Task)
What is the relationship between the categories of tags and
users’ perceptions of the usefulness of these terms as
indicated by their ratings of a set of pre-assigned terms?
Is there a relationship between tag length and tag assignment
Is there a relationship between tag length and user’s
perception of its usefulness?
The study employed a controlled experimental design, asking a
sample of 35 participants to perform image description and pre-
assigned term evaluation tasks using modified Steve tagger
Participants were undergraduate and graduate students and staff
members recruited from the College of Communication and
Information at Florida State University. Pre-experiment survey
questions indicated few participants were familiar with the
concept of controlled vocabularies; more were familiar with
tagging, but the majority had not done tagging before.
In the description task, participants were given 10 sampled
photographs selected from a set of 7,192 photographs from the
Library of Congress Flickr photostream; they described each of
these photographs by assigning tags. Next, in the evaluation task,
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participants rated a set of pre-assigned terms for each of the 10
photographs by their usefulness for describing the content of the
photographs on a five-point Likert scale (i.e., ‘strongly disagree’,
‘disagree’, ‘neutral’, ‘agree’, ‘strongly agree’). The pre-assigned
terms were obtained from the following sources: (a) the
Thesaurus for Graphic Materials, (b) the Library of Congress
Subject Headings, (c) tags assigned to the photographs by Flickr
members, (d) a folksonomy generated from the Library of
Congress photostream on Flickr, (e) the folksonomy from the
complete Flickr database, and (f) the English Wikipedia. The pre-
assigned terms were obtained as described previously in . To
examine the relationship between tag categories and tag
assignment order, for each combination of tag, image, and
participant, tags were assigned numbers indicating the order in
which the participant assigned the tag to the image. Next, two of
the researchers coded each tag according to Jörgensen’s coding
scheme of broad categories composed of several specific types of
attributes [4, 5], with the addition of a new category, that of
“Group,” referring to organizations, institutions, or social groups
with a particular purpose or goal, as opposed to a transient or
spontaneous gathering of people. While terms with this meaning
had previously been assigned to another category, their frequency
in this particular set of data, especially where additional text
information about the image appeared, suggested the utility of this
The Wilks-Shapiro test showed that neither tag assignment order
nor term ratings were normally distributed. Hence, the researchers
used a nonparametric Kruskal-Wallis test to examine relationships
among tag categories, tag assignment order, and term rating. The
Kruskal-Wallis test showed that both specific and general tag
categories were statistically significantly different on the order of
tag assignment (χ2 = 132, df = 28, p < 0.001; χ2 = 58.6, df = 11, p
< 0.001). Table 1 shows that, on average, Group was the first
assigned broad category of tags, followed by Color, Art
Historical, Story, People, Human Attributes, and Abstract.
Table 1. The mean and median of order of tag assignment for
general codes (average tags per image = 5.7).
Similarly, two of the researchers also coded the pre-assigned
terms according to Jörgensen’s coding scheme [4, 5], with the
same addition of Group. The Kruskal-Wallis test showed that both
specific and general codes were statistically significantly different
on usefulness ratings (χ2 = 549.8, df = 24, p < 0.001; χ2 = 251.2,
df = 11, p < 0.001). Table 2 shows the average rating of Group
terms was the highest, followed by Human Attributes, Abstract,
People, and Description categories.
The study did not find significant associations between tag length
and assignment order (Spearman's rho 0.06, p<0.01) and between
pre-assigned term length and perceived usefulness (Spearman's
rho 0.07, p<0.001).
Table 2. Categories of terms by ratings (1:least useful to 5:
most useful; based on 12,180 user ratings).
The preliminary findings of the study suggest that while in some
instances users might assign broad categories of terms that they
perceive most useful first, order is not necessarily an indicator of
perceived utility. While term order could guide library and
museum communities in identifying useful and important index
terms for their image collections at a relatively low cost, these
results indicate that at the broader level of category order, the
results are more variable. Future steps in the study include
examining the relationship between perceived usefulness and
assignment order at the term, or tag level.
One of the limitations of this study is that participants were self-
selected from a single academic department. Replicating the
experiment with a larger and more representative sample of
participants and a larger sample of photographs would be
desirable to strengthen the findings of the study.
This research is partially supported by an OCLC/ALISE Research
 Chung, E., and Yoon, J. 2008. A categorical comparison
between user-supplied tags and web search queries for
images. In Proceedings of the American Society for
Information Science and Technology, 45, 1, 1-3. DOI=
 Cunningham, S., and Masoodian, M. 2006. Looking for a
picture: An analysis of everyday image information
searching. In Proceedings of the 6th ACM/IEEE-CS Joint
Conference on Digital Libraries (Chapel Hill, North
Carolina, June 11 - 15, 2006). JCDL ’06. ACM, New York,
NY, 198-199. DOI=
 Golbeck, J., Koepfler, J., and Emmerling, B. 2011. An
experimental study of social tagging behavior and image
content. Journal of the American Society for Information
Science and Technology, 62, 9, 1750-1760.
 Greenberg, J. 2001. Quantitative categorical analysis of
metadata elements in image application metadata schemas.
Journal of the American Society for Information Science and
Technology, 52, 11, 917-924. DOI=
 Jörgensen, C. 1995. Image attributes: An investigation.
Unpublished Ph.D. thesis, Syracuse University.
 Jörgensen, C. 1998. Attributes of images in describing tasks.
Information Processing and Management, 34, 2/3, (Mar. -
May, 1998), 161-174. DOI=
 Jörgensen, C., Stvilia, B., and Jörgensen, P. 2008. Is there a
role for controlled vocabulary in taming tags? In
Proceedings of the 19th Workshop of the American Society
for Information Science and Technology Special Interest
Group in Classification Research. Columbus, OH.
 Matusiak, K. K. 2006. Towards user-centered indexing in
digital image collections. OCLC Systems & Services:
International Digital Library Perspectives, 22, 4, 283-298.
 Rolla, P. J. 2009. User tags versus subject headings: Can
user-supplied data improve subject access to library
collections? Library Resources and Technical Services, 53, 3
(Mar. 2009), 174-184.
 Stvilia, S. and Gasser, L. 2008. Value-based metadata quality
assessment. Library and Information Science Research, 30, 1
(Mar. 2008), 67-74. DOI=
 Stvilia, S. and Jörgensen, C. 2009. User-generated collection
level metadata in an online photo-sharing system. Library
and Information Science Research, 31, 1 (Jan. 2009), 54-65.
 Stvilia, S. and Jörgensen, C. 2010. Member activities and
quality of tags in a collection of historical photographs in
Flickr. Journal of the American Society for Information
Science and Technology, 61, 12, 2477-2489. DOI=
 Stvilia, S., Jörgensen, C., and Wu, S. 2011. Establishing the
value of socially created metadata to image indexing.
Library and Information Science Research (in press).
 Wetterstrom, M. 2008. The complementarity of tags and
LCSH—A tagging experiment and investigation into added
value in a New Zealand library context. The New Zealand
Library and Information Management Journal, 50 (May.