Video Transcript
Is the following a survey, an
observational study, or an experiment? A company has developed non-toxic
oil paints. To investigate whether this new,
environment-friendly product has attracted new clients, client and sale data were
analyzed.
So, in order to answer this
question what we need to first look at is what a survey, an observational study, or
an experiment are. Well, first of all, we’ll take a
look at a survey. And a survey is data collection
from a predefined group who give answers or insights on specific or varied
topics.
So, if we take a look at an
observational study. This is where subjects are observed
and results are measured but independent variable is not controlled by
investigator. And this is often for ethical or
logistical reasons. For example, if we were looking
into the effect of air quality on lung capacity, then it would not be ethically
sound to give one group bad quality air while the other group had good quality
air. Because, yes, that could show the
difference between these types of quality air on lung capacity. However, giving one set of people
within the study bad quality air would not be ethically sound. So, we could not use that kind of
experiment.
And then finally, for an
experiment, well, in an experiment, investigators control variables and observe
outcomes. So, it has similarities to the
observational study, but it’s in a much more controlled environment.
So, now what we need to do is work
out whether our scenario is a survey, an observational study, or an experiment. So, let’s remind ourselves what the
scenario is again. So, it’s a company who have
developed a non-toxic oil paint. And they want to see whether the
new product has attracted new clients. And to achieve that, what they’ve
done is analyze client and sale data. Well, this seems more aligned to an
observational study.
Because it’s not a survey, because
they haven’t sent anything out and they aren’t asking specific questions of their
clients. And it’s not an experiment, because
they’re not controlling the variables. And this is because if we think
about the scenario, then there have been a number of factors to whether the sales
increased or decreased over a certain period. And they haven’t controlled all of
these, so therefore, it wouldn’t be an experiment. So therefore, we can say that the
scenario we’re looking at is an observational study.