How about teachers who say they teach the „scientific“ method of singing?
Many teachers in recent history have fallen victim to what has been erroneously termed „voice science“. You see, any time you associate something with the word „science“, it automatically assumes an aura of truth. That's very attractive to both teachers and students, who are anxious to grab onto anything that offers them hope of understanding what has unfortunately become a very confusing subject.
You should be able to sing through your entire range – from the lowest notes of your chest voice, up through the highest notes of your head voice – in a smooth, even, or what we call connected manner, and still maintain a relaxed speech-level posture.