The phrase "ascertain the difference" is correct and usable in written English.
It can be used when you want to determine or find out what distinguishes two or more things from each other.
Example: "In order to make an informed decision, we need to ascertain the difference between the two products."
Alternatives: "determine the difference" or "identify the difference".
"The public's ability to ascertain the difference between good versus mediocre has ratcheted up," Mr. Coraine said.
What I am going to do is try to ascertain the difference between what Mr Whiting calls the "old-fashioned values of traditional literature" and the "dark, demonic literature" that drips from every corner of our modern world.
It is therefore critical to examine the underlying innovation relations not only in the East Asian region, but also in the integrated region of East Asia and the USA and to ascertain the difference between the two.
"What's the point of celebrating -– or hell, even learning about -– diversity if school administrators are unable to ascertain the difference between Black, African American, and African?
While transitioning to a new country is exceptionally difficult, refugees make great strides annually and by the fourth year make it difficult to ascertain the difference between a refugee from Iraq or a native born American citizen.
The only way to truly ascertain the difference between standard- and high-dose chemotherapy is to perform a randomised trial.
Listing the priorities is only the first step in a long agenda that must be carefully planned and executed and more work needs to be done in order to ascertain the differences in research priorities between high and low resource settings, or between different continents.
To ascertain the differences between the situational factors of risky and safer sexual encounters in college students.
Objective: To ascertain the differences among hospitals in Japan in the management patterns and outcomes of patients with acute myocardial infarction (AMI).
To ascertain the differences in smoking characteristics between a group of smokers with COPD and another group of healthy smokers, both of which were identified in a population-based epidemiologic study.
An experimental study has been undertaken to ascertain the differences in dynamic behaviour of cast-in and retrofitted shear connectors using a series of identical steel-concrete composite beams with various shear connection systems.
