General errors in information use.
Oversimplifying a concept. Suppose you have two concepts C1 and C2 where C2 is taken to be a simpler way to explain C1.
Unless exactly all and only the content in C1 is expressed in C2, C2 is lossy - an inaccurate surrogate.
Appropriately simplifying a concept is strictly to explain C1 in fewer terms while completely capturing all the semantic content of C1.
Consider two concepts:
Science > Research since Research is part of the activity of Science but Science is also many other kinds of activities too.
Thus, to say "Science is Research" is oversimplifying the concept in a lossy way. It might be convenient to say or interesting as a turn of phrase but if the intent is to teach the concept of Science, the lossy approach is wholly inadequate.
"Research is a major part of science. So is verifying that research. Scientists formulate ideas into rigorous theories that are tested using powerful mechanical and intellectual tools..."
This is not to break a complex concept down into parts where:
In such a scenario, the translation is not lossy.