The document discusses defining impact metrics for social enterprises. It recommends selecting 1-5 metrics that measure outcomes such as number of jobs created or lives positively impacted. Metrics could be outputs (what is done), outcomes (actual impacts), or proxies (linking outputs to outcomes). The IRIS catalog contains generally accepted metrics for impact investors. Examples are provided such as number of individuals trained or greenhouse gas reductions. The example impact metrics track outcomes like increased income, reoffending rates, and environmental impacts.