"make a direct comparison" is a correct and usable phrase in written English.
You can use it to describe when two items are being compared in an explicit, direct way. For example, "The salesman made a direct comparison between the quality and value of the two cars."
However, we believe that differences between our experimental setups make a direct comparison of our results difficult.
The same design was used for both the VR and real robot in order to make a direct comparison.
Matic's presence provided an opportunity to make a direct comparison between a ready-made defensive midfielder and an emergency one.
The Jane's numbers for 2015 are different from those in the Global Terrorism Database, so it's impossible to make a direct comparison.
In an effort to make a direct comparison with the conventional gasoline-only Lexus, I contacted Toyota and asked for an RX330 test car.
Although Garfield does not make a direct comparison, the delight of this book is seeing the parallels to present-day trends in technology.
In this study, scratch tests were also performed on pure Nb and a solid-solution strengthened Nb-based C103 alloy to make a direct comparison.
The proposed method has been set up and we make a direct comparison with a commercial heterodyne interferometer by measuring the displacement of the same target mirror.
Wind tunnel experiments were also conducted for pitch control using the same blade model in order to make a direct comparison.
In this study we make a direct comparison between the currently known fluorine-18 labelled GABAA radiotracers and novel imidazobenzodiazepine ligands.
At about $2.75 billion, Silver Lake's valuation appears rich compared with some of its competitors, though it is hard to make a direct comparison because it is private and does not disclose its financial details.
