I have heard it said that if a person is under conviction, that this means that the Lord has placed upon that heart the desire to not do this thing, or do it, as to whatever applies. A preference is a choice you make. I believe conviction can be confused with preference. There are some that believe they are under a conviction, but if the Bible doesn't back up the "conviction", it can't be a true conviction. And I also believe that preferences can also be wrong, if against the Bible. So, when a person throws at you that this is their personal conviction, have they just thrown up a wall before you, telling you that they will not change their belief? And when a personal preference is stated, is this a way of stating that they are set in their ways, and will not be open to change? Do you find these two words thrown about freely, without a thought of their true meaning?