"The most rigorous study yet"
I searched the article for placebo and didn't find any mention.
I searched the article for placebo and didn't find any mention.
The kind of thing you're talking about would be an experiment, where they bring people in and use various measures to quantify various types of intelligence after smoking marijuana. In that situation yes you could use a placebo as one group. But even then it's not always appropriate, and just skimming an article and dismissing it by saying "no placebo!" makes no sense. Not all experiments do use or should use a placebo as part of their methodology, and this isn't even an experiment.
It can be appropriate it you get consent to be part of the experiment. You don't have to have the whole student body be part of the experiment.
Well then this "study" is just an observation. So it probably doesn't warrant the amount of attention it is getting, to say nothing of people using this "study" as evidence. Observation is an early step of the scientific method, but now they need to perform a scientific experiment in order to make this newsworthy. (Well I guess it is "newsworthy" in that it makes for high click-through...)
Yes. Many studies are.
> So it probably doesn't warrant the amount of attention it is getting, to say nothing of people using this "study" as evidence.
It seems like you lack an understanding of how science works? Because the fact that this is an observation doesn't mean that it isn't evidence. Observation is like one of they key kinds of evidence.
>but now they need to perform a scientific experiment in order to make this newsworthy
No they don't. That's not how this works, at all. It's still valid meaningful evidence. I mean, do you ever read stories about stellar discoveries? Do you think they aren't worth reading because they didn't do an experiment to re-create the black hole they discovered in a lab?