Tactics Used When Searching for Digital Videos

Barbara M. WildemuthJung Sun Oh

Gary MarchioniniUniversity of North Carolina at Chapel Hill

The research question

Which search tactics do people use when they search for digital videos?

Some vocabulary

What do we know already?• The most frequently-used search move is to

add terms/concepts, to decrease the search results (Vakkari et al., 2003; Wildemuth, 2004)

• 22-33% of Web queries are modifications of a previous query (Jansen et al., 2000, 2009; Spink et al., 2000)

• People do change their search tactics when presented with different capabilities (Kules & Shneiderman, 2008)

Sample of participants• 36 graduate and undergraduate

students from 17 different departments

• 75% watch videos daily or weekly• 36% search for videos daily or

weekly

The database of videos

Data collection procedures• Demographic questionnaire• Conduct searches (x4)– Assigned search tasks– Conduct search and make relevance

judgments

• Transaction logs captured during searches

Search tasks

• Example:Imagine that you are an emergency response officer in California and that you are developing an online tutorial on how to respond to an earthquake. You would like to illustrate the tutorial with video showing the damage that can be caused by an earthquake.

Concrete Abstract

For viewing Role of rivers, recent videos America’s obsession with cars, 1930-1950

For production Earthquake damage Any topic, for montage of early, popular videos

Data analysis• Coding the search moves– Using codes based on Shute & Smith

(1993) and Bates (1979)– 1545 moves; ~11 moves per search

• Maximal repeating patterns (MRP) analysis to identify frequently-used tactics (Siochi & Ehrich, 1991)

• Combine similar MRPs to identify tactics

Search task:Imagine that you are a history professor, teaching a course on the history of technology in the U.S. You want to find some footage that illustrates America’s growing obsession with cars/automobiles between 1930 and 1950. (abstract; for viewing)

Search conducted by participant 40:Term: automobile + Term: 1930-1950

Display

automobile carDisplay

car car cultureDisplay

car culture car culture advertisingDisplay

Search task Queries

Search conducted by participant 40:Term: automobile + Term: 1930-1950 Display

automobile carDisplay

car car cultureDisplay

car culture car culture advertisingDisplay

Coding of participant 40’s search:New searchAdd conceptDisplayReplace termDisplayAdd conceptDisplayAdd conceptDisplay

Queries coded

#125

Coding of participant 40’s search:New searchAdd conceptDisplayReplace termDisplayAdd conceptDisplayAdd conceptDisplay

MRP identification

MRPs Tactic

Tactics B, C, F

Tactics K, L, M

Key findings• A small number of different moves

predominate: New search, Add concept, Delete concept, Display

• These moves are used to make up a wide variety of search tactics in video retrieval

• Transitions from search to display and back occur frequently

Implications for research• Concept-based coding allows

comparisons across IR systems• Concept-based coding may yield new

insights into people’s searching behaviors

• Behaviors, as recorded in transaction logs, don’t tell us what we’d like to know about cognition

Questions and comments?• Open Video website:

open-video.org

• Funding provided by NSF Grant IIS 0099638

Open Video: Advanced Search

Codes for search movesCode Definition

New search Enter term for a concept; no other terms yet included.

All No terms entered; all videos in collection are retrieved.

Add concept Add a concept not yet in query; implicit AND.

Delete concept Delete a concept from the query.

Narrow term Replace a term with a narrower term for the same concept.

Broaden term Replace a term with a broader term for the same concept.

Replace term Replace a term/concept.

Narrow operator Replace an operator with a narrower operator (ORAND).Broaden operator Replace an operator with a broader operator (ANDOR).Display Display results or modify the results display.

Correct Correct an error (e.g., spelling error) in the query.