The phrase "are not differentiated" is correct and usable in written English.
It can be used in contexts where you want to express that two or more items are not distinguished from each other.
Example: "In this study, the variables are not differentiated, making it difficult to draw clear conclusions."
Alternatives: "are not distinguished" or "are not separated".
For example, bone morphology does not differentiate terrestrial canids from cursorial canids and terrestrial felids are not differentiated from scansorial felids.
Moreover it has to be pointed out that the particles of the urban site are not differentiated in well defined clusters, even if an intra-cluster differentiation can be seen, in fact the particles can be grouped in accordance to their chemical composition.
They have 5 8 tepals (sepals and petals are not differentiated) enclosing 10 25 stamens or 5 6 carpels.
Unlike other chess variants, shogi pieces are not differentiated by colour to indicate side, though opposing players are known as white and black, with black moving first.
Chierchia (1998) talks about mass nouns or names of kinds instead of collective nouns, which in Chinese are not differentiated.
Our benchmark framework employs the simplest case in which patients are not differentiated by the severity of their condition.
It was also suggested that "noisy" and "annoying" are not differentiated in Japan, while in the other four countries these two adjectives are used in different ways.
Also, the data thus far are not differentiated according to department, so we may be comparing dramatically different disciplinary expectations.
Objective: The epidemiological risk factors for the different forms of diabetic macular edema (focal or diffuse) are not differentiated in the literature.
If the oriented buildings are not differentiated from the collapsed buildings, the building damage will be greatly overestimated, especially in built-up areas containing many oriented buildings.
"Process standardization" refers to standardizing the initial steps in the process across the product line so that products are not differentiated at these steps and distinct personalities of the products are added at a later stage.
