"Tipping Points," "Thought Power," and "Bacterial Bullseye"
From Uber to Instacart to DoorDash, apps have
revolutionized the service economy. But do the real-time feedback ratings customers give providers have any
impact on tipping?
Researchers at the Carlson School of Management
set up field studies to analyze how rating services impact
tipping behaviors. Their results show that the size of tips
decreases by an average of 17 percent when customers
are asked to rate service before tipping. And that’s not
just with apps. The researchers conducted a study at a
Twin Cities Chinese restaurant, where customers were
asked to rate service in order to help the restaurant
determine its employee of the month. Tips decreased by
13 percent after customers rated the service.
Why? Researchers think that customers believe a service ranking is in and of itself a benefit to the employee,
and therefore don’t feel as motivated to reward them
financially. If a customer believes an employee benefits
directly from the rating, they are less likely to be generous with tipping.
On the other hand, when customers were reminded of
their scores—say in a follow-up text—they tipped more.
“People have commitment and consistency motivations, which urge customers who give high ratings to tip
more,” said Carlson School Associate Professor Alison
Xu. “If I were to rate the driver five stars but decide to
give no tip at all, that can be inconsistent. But by reminding the customer about the high rating, the motivation to
be consistent is now at the top of their mind.”
This study was published in the June 2022 issue of Journal of Marketing.
Researchers at the U of
M’s College of Science
and Engineering are using
artificial intelligence (AI)
technology to help amputees
control prosthetic arms using
could operate prosthetics
through microchip devices
implanted in their muscles.
The breakthrough developed
at the University uses chip
technology implanted in the
peripheral nerve in a person’s
arm, and synchs the chip with
AI software to help interpret
signals from the nerve.
“With other commercial
prosthetic systems, when
amputees want to move a
finger, they don’t actually think
about moving a finger. They’re
trying to activate the muscles
in their arm, since that’s what
the system reads,” says Jules
Anh Tuan Nguyen (Ph.D. ’21),
a postdoctoral researcher in
CSE. “Our technology knows
the patient’s intention. If they
want to move a finger, all they
have to do is think about moving that finger.”
It’s a breakthrough researchers say could pave the way for
advances in helping not only
amputees, but people with a
host of neurological disorders
and chronic pain.
This research was first published in the October 2021 issue of Journal of Neural Engineering.
Known as “forever chemicals,” PFAS are a class of
that make everyday life
easier, from the coating
on nonstick pans to water-repellent rain gear. They
have also been linked to an
increased risk for serious
testicular cancer to thyroid
disease to miscarriages.
PFAS are also notorious
for accumulating in soil and
water. And because they
aren’t naturally occurring
in nature, they usually don’t
But Maddy Bygd, a
graduate student in the U of
M’s microbial engineering
program, together with
University Professor of
Biology and Biophysics Larry
Wackett, has identified a
bacterium that can break
down these chemicals and
turn them into harmless
fluoride and carbon.
Using a new method she
devised, Bygd identified a
bacteria called Pseudomonas
putida F1, which is a promising
candidate to remediate PFAS
in soil because it is naturally
occurring and has been shown
to break down compounds
that resemble PFAS.
This research first appeared in the December 2021 issue of mBIO.