Private contractors are interested in the certifications offered by Agency A$.$ The certification includes information on Agency A$\text{'}$s website, online training modules, and in$-$person sessions Many private contractors have gained introductory knowledge by completing the self$-$guided modules online. Some private contractors have also participated in the classroom workshops and hands on training. These in person sessions cover more detailed aspects of the required material and special circumstances. In addition, with numerous fields for specialization and corresponding premium pay rates for certified experts, it is expected that high participation rates in the certification program will continue. What is the main idea of the passage?