​Training Schools aim to facilitate capacity building on a topic relevant to the theme of the respective COST Action through the delivery of intensive training on a new or emerging subject. They can also offer familiarisation with unique equipment or expertise and are typically, although not exclusively, considered to be for the benefit of Young Innovaters and Researchers.

Training Schools serve to help the Action achieve their MoU Objectives and deliver impact with regard to:
• Capacity Building: Allowing COST Actions to provide training for Researchers and Innovators in highly specialised topics which are essential for the Action. They are the tool for transferring know-how among all types of actors and building interdisciplinary expertise;
• Research Coordination: Training Schools can also be used for reaching specific results (e.g., data collection or analysis, training on methodologies developed by the Action) in support of the objectives of the COST Action.

Training Schools benefit to:
• Trainers:
    - Networking with colleagues and next generation of researchers working in the same area;
    - Setting the “standard” and/or shape new and emerging areas of knowledge;
    - Developing and improving their own teaching materials.
•  Trainees:
    - Meeting and networking with peers and leaders of the area and, build the next generation of researchers;
    - Getting critical knowledge and skills to deepen their own research;
    - Creating potential for career opportunities.

WHEN ORGANISING A TRAINING SCHOOL
1. A Training School shall have COST Action objectives as its focus.
2. Training School shall be held in a participating COST Full or Cooperating Member or in an institution with which an NNC Action Participant is affiliated.
3. The COST Action also shall be one of the primary organisers of the Training School and shall be clearly promoted on all dissemination channels, namely the official website of the Action / event, brochures and all relevant training material.
4. There should be a reasonable country balance concerning trainee participation.
5. Training Schools are recommended to last a minimum of 3 days.
6. A ratio of at least 3 Trainees to 1 Trainer is recommended.

Eligibility rules and more to be seen in Annotated Rules for COST Actions.