concise word or phrase to express the idea that one does not make a judgement due to lack of information

Question

Say that someone asks for an individual's opinion on topic X. The individual does not personally feel that they understand the topic sufficiently to make a valid decision, due to lack of knowledge about nuances of the decision. I'm looking for a phrase to concisely express a lack of opinion on the topic due to a recognition that the individual does not yet feel they understand the topic sufficiently to have made a reasoned decision.

I am not referring to situation where sufficient information does not exist for anyone to make an informed decision. I'm referring more to situations where information does exist, and given some time he, the individual, could understand that knowledge, but at that moment they do not feel they have a sufficient grasp of that information personally.

For instance, if someone is asked if they support a new law, where the details of the law are readily available to be read, but the individual has not yet, or may never, read the law sufficiently to understand the nuance of the law in order to determine rather they agree with it

I'm looking to avoid a phrase like "reserve judgement" because this implies an intention to learn about the topic sufficiently to make a judgement later. I'd like a phrase that could likewise imply "I lack knowledge to make a decision now, and am not inclined to commit the effort to gain that knowledge in the future, so I choose to abstain from the discussion and not attempt to draw a conclusion".

A phrase that allows one to express a tentative opinion while also acknowledging a lack of commitment to the opinion due to similar lack of knowledge as above would also be nice, but I'm mostly looking for the former.

Answer 1

It's not easy to find a suitable phrase, but you could consider saying,

I can't make an informed decision (now), but my initial response/idea/suggestion is that...

Informed in the sentence means:

(Of a decision or judgement) based on an understanding of the facts of the situation: she lacks the ability to make an informed decision.

[Oxford Online Dictionary]

However, you can never know the reason for your not being able to make an informed decision is lack of information available (more likely) or lack of your knowledge to understand it. It will depend on your context.

Answer 2

"defer judgment", "suspend judgment" are not all that much different from "reserve judgment" but possibly less definite on the eventual resumption.

"refrain from judgment" is definitely something that can end up as permanent postponement.

Answer 3

I’m reluctant to answer that question [now] because I’m simply/frankly not [yet] up to speed on that [topic].

up to speed

1. …
2. Informal Fully informed; conversant: I'm not up to speed on these issues yet.

(from American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2011 via ‘The Free Dictionary by Farlex)

The bracketed [now] and [yet] would make it clear that the intention is to eventually answer once the speaker gets/is brought ‘up to speed.’
It’s arguable, however, that using ‘not up to speed,’ even without ‘yet,’ might give the impression that one will eventually make the effort to get there, which would admittedly render it more suitable for your secondary inquiry.
If that is the case, perhaps the addition of ‘simply’ or ‘frankly’ would help convey the “don’t know, don’t care" notion of your primary use/inquiry.

Here's an example of usage from ‘From the Bureau to the Boardroom: 30 Management Lessons from the FBI’ by Dan CARRISON via Google Books.