用いる

1. Origins, structure, and basic meaning

• Structure: 用いる (もちいる) is a somewhat formal transitive verb for employing a means or method. The examples contrast 用いた with negative 用いない.
• Basic usage: An experiment adopts two measurement methods; an explanation is deliberately kept free of difficult language.

2. Common pitfalls and similar expressions

• Method adopted and difficult wording avoided
  • The employed item is marked by を in both sentences. 用いないようにした expresses a deliberate policy of avoidance, not merely a present negative fact.