Translation of the word "informational" and "orientational"


I wonder, how could I express the same meaning for "informational" and
"orientational" in Japanese? I used **有益的【ゆうえきてき】** to mean "informational"
and **おおよその/近似の【きんじ】** to mean orientational. But, I am afraid, that I am too
far from the right usage, as I use this words mainly for the **gauge=meter** ,
which is **not calibrated**. So I say:

> Informational/ orientational **gauge**

Also, I would be glad to know, if the offered translation for these two words
will be same, in case of changing the context in a next way.

> Orientational/Informational **notes**

Hope I haven't complicated the question too much. Hope to hear your opinion
and thanks to everyone in advance!




I'm not sure, but maybe you might want
[目安【めやす】](http://jisho.org/word/%E7%9B%AE%E5%AE%89). This noun implies the
value may not be very precise, but it also implies it works fine at least as a
rough estimate or a guideline. [See examples on
ALC](http://eow.alc.co.jp/search?q=%E7%9B%AE%E5%AE%89).

  * BMIは必ずしも信頼性は高くないが、肥満度を測る目安としては使える。  
BMI is not necessarily reliable, but usable at least as a rough measure of
obesity.

  * テレビの視聴率など目安に過ぎない。  
Viewership rating is no more than a rough indicator.

I'm afraid I don't quite get what an "orientational/informational notes" means
for now... Could you explain or rephrase it?

