This request for proposal (RFP) is to conduct consultations and develop an instructional design plan to revise the foundational CES evaluation course, Essential Skills Series (offered in EN and FR). ESS is offered in-person and online through the CES e-Institute. The in-person version has not been updated since 2014. The e-Institute online version was updated in 2017. The ESS revision should reflect new developments in the evaluation field (e.g., GBA+, sustainability, culturally responsive practices); the revised CES competencies; renewed ethical principles; diversity, equity, and inclusion; and learnings from the delivery of in-person and online ESS sessions.