Could somebody please explain to the researchers how to do a scientific study?

In a scientific study you have what is called a "control", which allows you to compare the set with trait "A" to a set without trait "A".

I do not see any such control in their study.

Is it possible that black Toronto folks feel targeted at only half the rate as Chinese Canadians? Is it possible that black Toronto folks feel targeted at exactly the same identical rate as white people?

Apparently one cannot know from this study because there is no control arm.

It is stunning to me that this was overlooked in the design of the study.