The phrase "made several observations" is correct and usable in written English.
For example, "The researcher made several observations during the experiment which were later used as evidence in the study."
In it, Jackall made several observations that dovetailed with those of Arendt.
While eating in Chinese restaurants, he made several observations, including how it is rare to see only two people dining at a table, how so many dishes effectively marry sweet and savory tastes, and how much he enjoyed the inclusion of tea with many of the meals.
A 500-page Navy board of investigation report published a few months later made several observations: Flight leader Lt. Charles C. Taylor had mistakenly believed that the small islands he passed over were the Florida Keys, so his flight was over the Gulf of Mexico and heading northeast would take them to Florida.
We have made several observations that make this unlikely.
We have made several observations that are consistent with this.
We made several observations from our evaluation of these data.
Observing Piezo1 activity in multiple patch configurations also allowed us to make several observations.
In the book, he also makes several observations about Woods's marriage, before and after the revelations of his affairs.
After clarifying the above points, I would like to make several observations: It's alarming that you, The Economist, would echo just one side of the case, because this evidences an ethical violation of the media's duty to investigate, consult, double-check sources, fact-check and verify information before publishing.
Here we can make several observations.
We can make several observations from the figure.
