Research conducted by: Statistics
Case study prepared by: David
Naming the ink color
of color words can be difficult. For example, if asked to name the
color of the word "blue" is difficult
because the answer (red) conflicts with the word "blue."
This interference is called "Stroop Interference" after
the researcher who first discovered the phenomenon.
This case study is a classroom demonstration. Students in an introductory
statistics class were each given three tasks. In the "words"
task, students read the names of 60 color words written in black
ink; in the "color" task, students named the colors of
60 rectangles; in the "interference" task, students named
the ink color of 60 conflicting color words. The times to read the
stimuli were recorded. There were 31 female and 16 male students.
Questions to Answer
conflicting color names faster or slower than naming color rectangles?
Which is faster, naming color rectangles or reading color names? Are
there gender differences?
This was not a
well-controlled experiment since it was just a classroom demonstration.
The order in which the students performed the tasks may not have been
counterbalanced or randomized.
Descriptions of Variables
||1 for female, 2 for male
||Time in seconds to read 60 color words
||Time in seconds to name 60 color rectangles
||Time in seconds to name colors of conflicting words
Stroop, J.R. (1935). Studies of interference
in serial verbal reactions. Journal of Experimental Psychology,
text of the above reference.
- Compute the mean for words.
- Compute the mean and standard deviation for "colors."
- Create parallel box plots for males and females for
- Create back-to-back stem and leaf plots for "colors"
as a function of gender (You may have to do this by hand).
- Create a stem and leaf plot for "interference."
- Create a scatterplot showing "color" on the
Y-axis and "words" on the X-axis.
- Compute the correlation between "color" and
- Compute the correlation between "color" and "words" using
only the 23 fastest color-namers.
- Do a t test comparing males and females on "color."
- Compute the 95% confidence interval for "interference."
- Do a t-test of the difference between "colors"
- Do a 2 x 3 ANOVA with gender as the between subject
variable and task (Colors, Words, Interference) as within-subject