The speaker concludes that the scent of lavender provides
an effective short-term cure for insomnia, supported by a three-week experiment
in which researchers monitored the seemingly apparent effects of
sleeping on lavender-scented pillows among 30insomniscs.
Without further information showing the validity of the experiment,
however, the speaker's account of the result of the experiment remains questionable.
A threshold problem involves the definition of a critical term, insomnia,
over whose understanding the speaker may have some confusion.
As commonly known, insomnia stands for an inability to fall asleep.
In this case, how soundly or long a person sleeps, or how tired a person feels after sleep,
is irrelevant to whether the person suffers from insomnia. In short, without a clear and unanimous
definition of insomnia it is impossible to assess the strength of the argument.
Another piece of evidence critical for evaluating the argument is the test subjects' sleep patterns
just prior to the experiment. It is impossible to conclude with any confidence that
the subjects benefited from sleeping on lavender-scented pillows without comparing their
sleeping status with or without the pillows. Moreover, regarding the facts that
the subjects slept more soundly and awakened less tired the first week than the second,
and that they used their regular sleep medication the first week but not the second,
I cannot find logical function of these facts toward bolstering the speaker's conclusion.
This evidence tends to show only that the subjects' other sleep medications were effective;
it proves nothing about the effectiveness of lavender.
Furthermore, the speaker's account for the experiment's third week, during which
the speaker reports only that the subjects slept longer and more soundly than
in the previous two weeks, is problematic. We are not informed whether the subjects
took any medication during this week. Assuming they did not, any one of a variety of factors
other than the lavender-scented pillows might explain this week's results.
Perhaps the subjects were simply making up for sleep they lost the previous week–when they
discontinued their regular medication. Or perhaps the subjects were finally becoming accustomed to
the pillows and the experiment environment, which actually disturbed their sleep initially.
In short, without evidence to rule out other explanations for the third week's results, the speaker
cannot confidently identify what caused the subjects to sleep longer and more soundly that week.
Two final problems with the argument involve the experiment process. The experiment's results
are reliable only if all factors that might affect sleep patterns remained constant during
the three-week period, and if the number of experimental subjects is statistically significant.
Without evidence of the experiment's methodological and statistical reliability,
the speaker's conclusion if unjustifiable.
In conclusion, the argument is unconvincing for the main reason that the experiment
environment cannot fully meet scientific requirements. To make the outcome of the experiment
more convincing, the author must provide evidence that the test subjects' insomnias was
worse prior to the experiment, and that the number of subjects is statistically sufficient
to warrant the conclusion. For best results, the author had better make aa comparison between
the sleeping pattern of insomniacs who sleep on the lavender-scented pillow and
the pattern of their counterparts who have similar level of insomnia while do not
sleep on the pillow under a controlled experiment environment.