Solved – Is regression of x on y clearly better than y on x in this case

An instrument used to measure the levels of glucose in a person's blood is monitored on a random sample of 10 people. The levels are also measured using a very accurate laboratory procedure. The instrument measure is denoted by x. The laboratory procedure measure is denoted by y.

I personally think y on x is more correct because the intention is to use the instrument readings to predict the laboratory readings. And y on x minimises the errors of such predictions.

But the answer provided was x on y.

Lots of lab papers, especially the instrument testing experiments, apply such x on y regression.

They argue that from the data collection in the experiment, the y conditions are controlled, and get x from the instrument reading (introducing some error in it). This is the original physical model of the experiment, so the x~y+error is more suitable.

To minimize the experiment error, sometimes, y being controlled on the same condition, then x is measured for several times (or repeated experiment). This procedure may help you to understand the logic behind them and find x~y+error more clearly.

Similar Posts:

Rate this post

Leave a Comment