uninformed
adj.not having enough information or knowledge about a specific subject. You use this to describe someone who does not know the facts before making a decision.
adj.lacking knowledge or information regarding a particular subject or situation. Often used to describe a person's state before receiving new data or instructions.
“The uninformed public was surprised by the sudden change in policy.”
“The committee made a decision based on uninformed assumptions, leading to a major failure in the project's first year.”
“In an era of rapid information exchange, being uninformed is often a choice rather than a necessity, though it can lead to significant social and economic disadvantages.”
From un- + informed.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.