collecting written testimony, documents, and other evidence used in trial is called

 Collecting written testimony, documents, and other evidence used in a trial is called "discovery." Discovery is a critical phase in legal proceedings, particularly in civil cases, during which both parties involved in a legal dispute have the right to obtain evidence from the other party. This process ensures that both sides can gather the factual information necessary to build their cases before going to trial.

There are several methods of discovery, including:

1. Interrogatories: These are written questions that one party sends to the other, which must be answered in writing and under oath. 2. Depositions: Oral testimony given by a witness or a party in the case before the trial, taken under oath and recorded for later use in court. 3. Requests for Documents: Parties can request each other to produce documents relevant to the case. 4. Requests for Admission: This is a method by which one party can ask the other to admit certain facts in writing, thereby narrowing the issues to be litigated. 5. Subpoenas: A court order requiring an individual to appear in court and/or produce documents or evidence.

The rules governing discovery are designed to prevent surprises during the trial and allow both sides to have the same access to important facts, promoting a fair trial.