When choice is demotivating: Can one desire too much of a good thing?

by Sheena S. Iyengar and Mark R. Lepper
Journal of Personality and Social Psychology,
Vol. 79, # 6, 2000, pp. 995-1006.

Hypothesis accepted: The number of options displayed affects consumers' initial attraction to or subsequent purchase of the displayed product.

Experiment supporting hypothesis

Location: Dreager's Grocery Store in Menlo Park, California

Groups:

• Experimental group #1: taste testing booth offering 6 jars of Wilken & Sims (Purveyors to Her Majesty the Queen) gourmet jams costing between $4 and $6. This is called the "limited-choice option."


• Experimental group #1: taste testing booth offering 24 jars of Wilken & Sims (Purveyors to Her Majesty the Queen) gourmet jams costing between $4 and $6. This is called the "extensive-choice option."


• No control group

Experiment:

• On two Saturdays, taste testing booth was set up for five hours in Dreager's Grocery Store.


• The 6-jar and 24-jar booth was switched each hour.


• Everyone approaching booth was encouraged to taste as many jams as they wished.


• Everyone was given a dollar-off coupon for purchasing a Wilkins & Sons jam to be selected from regular shelves containing 28 jams.

Results:

Even though the 24-jar booth attracted 20% more people than the 6-jar booth, about the same number of jams were actually tasted and, amazingly, the 6-jar booth sold 7 times more jars of jam. The researchers explained, "... an extensive array of options can at first seem highly appealing to consumers, yet can reduce their subsequent motivation to purchase the product."



This paper reports on two more experiments.

• Experiment two showed that students were more likely to write an extra credit paper and write a better paper when choosing from a list of 6 rather than 30 topics.


• Experiment three revealed that people claimed to enjoy more selecting from a display of 30 chocolates than a display of 6 topics. However, those selecting from a display of 30 chocolates were also more likely to be dissatisfied, regret their choice and, when given a choice of $5 or a box of chocolate worth $5, to choose the chocolate.
  

Application to libraries:

1. One major difference between this study and selecting books in a library is that this study asked people to spend $3 to $4 for a jar of jam. Library books are free. This difference may undermine the application of this study to library situations.


2. Nevertheless, this study suggests that library book displays may have an optimal size that would circulate more library books than displays larger and smaller. That optimal size would be the balance point between large enough to attracting patrons, but small enough to encourage people to pick.


3. Maybe the best display would be a large display composed of smaller displays on a variety of topics. The large size would be easily seen at a distance and draw people to the display. When people reached the display, they would see many small displays on a wide-variety of topics. The small size of each display would make selection easy and quick.


4. Bibliographies do not have to be comprehensive. A short list of selected titles will do.
   

The Effect of prime display location on public library circulation of selected adult titles

by Herbert Goldhor
The Library Quarterly
Vol. 42, # 4, October 1972, pp. 371-389.

Hypothesis accepted: "Adults borrow books from the public library primarily as a result of browsing and that which facilitates browsing will significantly increase circulation."

Experiment supporting hypothesis:

Location:

• Champaign (Illinois) Public Library: 97,000 volumes
• Urbana (Illinois) Free Library: 77,000 volumes

Groups:

• Experimental group: 318 copies of 102 titles of fiction and non-fiction on display in a prime location in Champaign Public Library
• Control group: 234 copies of 105 titles of fiction and non-fiction on regular shelves in Urbana Free Library
  

Experiment:

• Pre-test period: November 1, 1969 to April 30, 1970, circulation measured for all groups while on regular shelves.
• Test period: May 1, 1970 to October 31, 1970, circulation measured for all groups in experimental condition and control group on regular shelves.

Results:

Displays near the circulation desk increased the circulation of both fiction and non-fiction. Though fiction circulated three to four times more than non-fiction, displays increased circulation of fiction and non-fiction about the same percentage: 117% for fiction and 98% for non-fiction.





Displays of fiction, for women and non-students increase raw circulation numbers more than displays of non-fiction, men and students.

Though women circulated three to four times more books than men, displays increased circulation about the same percentage for women and men: 120% for women and 96% for men.




Displays increased non-student circulation by 223% and student circulation by a mere 49%.




There was no statistically significant difference between the libraries in the percentage of readers claiming to have read more than half or all of the book. Therefore, the ease of selecting displayed books does not reduce the actual use of the circulated books.

The Display phenomenon: An exploration into factors causing the increased circulation of displayed books

by Sharon L. Baker
The Library Quarterly
Vol. 56, #3, July 1986, pp 237-257.

Hypothesis 1 accepted: "Fiction books placed in a prime display location will circulate significantly more than their counterparts on the regular shelves or in a nonprime display location simply because they [i.e., prime location books] are more physically accessible and more visible to browsers."

Experiment supporting hypothesis 1
Location:

• Mahomet (Illinois) Township Library: 10, 230 volumes
• Monticello (Illinois) Township Library: 31,214 volumes

Groups:

• Experimental group at prime location: 75 adult fiction books placed spine out on bookcart near circulation desk
• Experimental group at nonprime location: 75 adult fiction books placed behind stacks at the back of the library
• Control group: 75 adult fiction books remained on regular shelves.

Experiment:

• Pre-test period: July 1, 1984 to September 30, 1984, circulation measured for all groups while on regular shelves.
• Test period #1: October 1, 1984 to December 31, 1984, circulation measured for all groups in experimental condition and control group on regular shelves.
• Test period #2: January 7, 1985 to April 6, 1985, books in prime and non-prime locations were reversed and then circulation was measured.

Results:

Sharon Baker notes that prime displays increased circulation of the books displayed, not the adult fiction collection as a whole.

In Mahomet Library with only 10,230 volumes, displaying books by the circulation desk increased their circulation 405% to 590%. Sharon Baker claims the prime display location circulated the most books because the books displayed at this location were "more physically accessible and more visible to browsers." This also supports the "principle of least effort" that people choose the most easily available resource even when better resources are available with a little more effort.





In Monticello Library with 31,214 volumes, displaying books by the circulation desk increase circulation even more, 784% and 708%. Circulation increase was largest in the largest library because, according to Sharon Baker in other articles, problems with information overload increase with library size.