Archive for December, 2008|Monthly archive page
Q: How many participants do we need for our cardsort?
Tullis and Woods conducted a real data simulation study to determine the practically optimal number of participants need for cardsorting.
First they collected data from a large set of users–168 people to be exact. Then they ran cardsort “studies” of different sizes by randomly drawing data for individual participants from the larger data set. Since it was all mathematical–based on similarity scores within data pairs and sets– it was easy (sort of) to “run the studies” enough times to understand the average variation that occurrs in the groups of different sizes.
Based on their simulations, Tullis & Woods concluded cardsorting studies with just 20-30 participants are robust and predictive.
Tullis, T., and Wood, L. (2004), “How Many Users Are Enough for a Card-Sorting Study?” Proceedings UPA’2004 (Minneapolis, MN, June 7-11, 2004).
Cold and lonely. These two concepts seemed permanently paired in the English language. So do warm and fuzzy. And new studies suggests that the linguistic link between emotional experience and physical sensation might not be so accidental. University of Toronto researchers Zhong and Lonardelli found that study participants describing a personal experience of social rejection or exclusion actually felt colder than others who remembered inclusive experiences. People describing negative experiences estimated the room temperature to be about 2.5 degrees C colder (That’s about 4.5 degrees difference in Farenheit.). Feelings, it seems, can influence our physical experience.
It seems the reverse holds true as well: Your physical world influences your attitudes and largesse toward others. To demonstrate this, researchers Williams and Bargh asked Yale University students to hold a cup of coffee for them—as a favor—during an elevator ride to the study location. Students who were asked to hold hot coffee subsequently described a third person as having a much warmer personality than those asked to hold iced coffee. Similarly, in a subsequent study, participants asked to test and rate a warm therapeutic pad demonstrated greater generosity than those who rated a cold one.
So the next time you want to make a good impression on someone, you may not need to buy them a cup of hot coffee. Instead you just ask them to hold yours ….
Zhong, C. and Leonardelli, G, J. (2008). Cold and Lonely. Does social exclusion litteraly feel cold? Psychological Science 19(9).
Williams, L.E. and Bargh, J. A. (2008).Experiencing Physical Warmth Promotes Interpersonal Warmth. Science 24(322) pp. 606 – 607.