Video summary
The video addresses Question 16 from a practice exam for Math 1030, focusing on identifying confounding variables in a specific research study. The study aims to determine whether scented masks affect learning speed compared to unscented ones by having participants solve mazes under different conditions. Each participant completes three mazes while wearing a floral-scented mask and three while wearing an unscented mask, with the order randomized to control for sequence effects. Additionally, participants rate their perception of the smell as positive, negative, or neutral, while researchers record the time taken to complete each maze.
A primary issue highlighted is that the study lacks a true control group because every participant experiences both treatments. Since subjects can clearly distinguish between the scented and unscented masks, they are aware of which condition they are in during each trial. This awareness introduces a significant psychological factor where participants might alter their performance based on their beliefs about the smell's effect, such as expecting to perform better with the floral scent or worse without it. Consequently, the results may be influenced by these expectations rather than the actual impact of the scent on cognitive function.
Furthermore, the experiment is not blinded, meaning both the participants and the researchers know which mask is being used at any given time. This lack of blinding opens the door to placebo effects in subjects and potential bias from researchers who might inadvertently influence the outcome or interpret data differently depending on their knowledge of the condition. The transcript also points out other unaddressed limitations, such as whether the mazes are identical in difficulty or if participants improve simply through practice over time. Without ensuring that all maze difficulties are equivalent and sufficiently randomized, it becomes impossible to isolate the scent as the sole variable affecting learning speed.
In conclusion, the study suffers from several critical confounding variables that undermine its validity, primarily stemming from the lack of a control group and the absence of blinding. The participants' ability to detect the scent creates a situation where their behavior is likely influenced by psychological expectations rather than the physical properties of the mask. Additionally, potential improvements due to practice effects and variations in maze difficulty are not adequately controlled for. These factors collectively suggest that any observed differences in maze completion times cannot be confidently attributed to the smell alone, highlighting the need for more rigorous experimental design in future iterations of this study.
Read the full video transcript
in this video we provide the solution to
question number 16.
for practice exam number four for math
1030 in which case we have a research
study that wants to determine whether
smell can affect learning or not so we
have uh participants who have to go
through a paper and pencil Maze and the
idea is how fast can they do it okay and
so to conduct the experiment our
participants are going to take they're
going to solve three mazes while wearing
a scented mask they're going to solve
three maze as well wearing an unscented
mask
um and then participants flew randomly
selected that they do three maths or
three mazes with the floral mask first
then three with the unscented mask and
then in the other group uh randomly
assigned participants will wear the
unscented mask for three mazes and then
a floral mask for three manges and so
then the researchers will record the
time it took to complete the mazes
um and then also participants will
indicate whether they found the smell
positive negative or neutral
okay and so that's the experiment that's
going to be conducted we have to
identify any compounding variables that
could interfere with this study so my
first thing to note here is that all
subjects uh experienced
both treatments okay
for which case
why why could this be a problem here so
we don't have a control group we don't
have a treatment group but since both
people get the experiment there they
both get the treatment and the control
what if that influences what they're
doing I mean after all the people we are
using in this study can most likely
smell uh if they can smell the mask so
they'll know when they're doing the
experiment uh you know let's let's put
this in a good way the the the the
participants
uh the the we'll say the subjects here
smell uh that'll be a little of our
humor here the subjects smell they can
smell so they know they know
which mask is the is the floral mask
okay as such the participants know even
you know we have randomized it right so
the order is randomized so that's a good
thing that they did there to try to
control some of the compounding
variables because one of the variables
could be that if you do the floral first
then the unscented that might make you
do better or worse than if you do the
unscented one then the floral because
what if the smell has a lingering effect
or the lack of smell has a lingering
effect so they did randomize that's a
good thing to try to control it but my
point is still that the participants can
know if they're smelling something or
not and because they can see the
difference they potentially could infer
a difference that oh maybe the smell is
better maybe the smell makes me do worse
um and so they psychologically could be
doing
um something in that regard the other
situation that I want us to be aware of
is that
um the the experiment is not blinded
that's really what I'm trying to get
here that the subjects will know which
one they're in they're will know whether
they're in the treatment group or the
control group when they're in both of
them their behavior might change because
of that it could be a positive or
negative as placebo effect people might
believe the smell is making it work
better because they're part of a study
uh and conversely but you also have that
the researchers themselves uh don't
the researchers themselves might
influence it because they know which is
being done at which time right another
situation that's not explained here is
how many
um how many different mazes are there
okay and we say that they they do maze
as multiple times is it the same maze
over and over again because that itself
might because it might get better over
time when they're doing The Mazes there
are they different mazes and if that's
the case if they're different mazes
um are they all the same difficulty
are the maze is the same difficulty and
so if those mazes are those mazes
sufficiently randomized so that the
difficulty is inherently the same and
the people are getting better because of
the smell or because of some other
things these are some confounding uh
factors that could be in play here some
of the limitations of the study uh this
is definitely not an exhaustive list but
these are some of the ones I'd be
concerned with the most