SCENARIO 11-6
Psychologists Have Found That People Are Generally Reluctant

SCENARIO 11-6
Psychologists have found that people are generally reluctant to transmit bad news to their peers. This
phenomenon has been termed the "MUM effect." To investigate the cause of the MUM effect, 40
undergraduates at Duke University participated in an experiment. Each subject was asked to
administer an IQ test to another student and then provide the test taker with his or her percentile
score. Unknown to the subject, the test taker was a bogus student who was working with the
researchers. The experimenters manipulated two factors: subject visibility and success of test taker,
each at two levels. Subject visibility was either visible or not visible to the test taker. Success of the
test taker was either top 20% or bottom 20%. Ten subjects were randomly assigned to each of the 2
x 2 = 4 experimental conditions, then the time (in seconds) between the end of the test and the
delivery of the percentile score from the subject to the test taker was measured. (This variable is
called the latency to feedback.) The data were subjected to appropriate analyses with the following
results. $$\begin{array} { l r r r r r } \hline \text { Source } & \text { df } &{ \text { SS } } & { \text { MS } } & { \text { F } } & \text { PR } > \text { F } \\\hline \text { Subject visibility } & 1 & 1380.24 & 1380.24 & 4.26 & 0.043 \\\text { Test taker success } & 1 & 1325.16 & 1325.16 & 4.09 & 0.050 \\\text { Interaction } & 1 & 3385.80 & 3385.80 & 10.45 & 0.002 \\\text { Error } & 36 & 11,664.00 & 324.00 & & \\\text { Total } & 39 & 17,755.20 & & & \\\hline\end{array}$$
-A campus researcher wanted to investigate the factors that affect visitor travel time in a complex, multilevel building on campus. Specifically, he wanted to determine whether different
Building signs (building maps versus wall signage) affect the total amount of time visitors require
To reach their destination and whether that time depends on whether the starting location is inside
Or outside the building. Three subjects were assigned to each of the combinations of signs and
Starting locations, and travel time in seconds from beginning to destination was recorded. How
Should the data be analyzed? $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$$\text { Starting Room }$
$\begin{array}{l}\begin{array} { l l l l } & \underline{ \text { Interior } } & &\underline { \text { Exterior } } \\ \text { Wall Signs } & 141,119,238 & & 224,339,139 \\\text { Map } & 85,94,126 & & 226,129,130\end{array}\end{array}$

A) Completely randomized design
B) Randomized block design
C) 2 x 2 factorial design
D) Levene's test