Effect sizes and the honest caveats, plus the things we refuse to sell you because the evidence isn't there.
A meta-analysis of 60 causal studies found instructional coaching improves teaching practice by roughly 0.49 standard deviations, among the largest effects in the field. The caveat we won't hide: effects shrink as programs scale, because fidelity slips. So we build for fidelity, with structured cycles, cadence, and dosage tracking, not just "assign a coach."
Kraft, Blazar & Hogan (2018), Review of Educational Research.
Comprehensive induction (a sustained, multi-component first year) is linked to lower new-teacher attrition and better outcomes. The caveat: the effect depends on how complete the program is. A one-day orientation and an unsupported mentor do little. That's why our induction is structured across the year, with matched mentors and logged check-ins.
Ingersoll & Strong (2011), Review of Educational Research.
The engagement research is consistent on one point: the payoff is in the action that follows a survey, not the survey itself. Asking and then doing nothing tends to erode trust rather than build it. So we never ship a survey without action-planning, owners, and report-back built in.
Teachers are more likely to engage honestly with developmental support when it's clearly separate from the rating that affects their job. That's a first-class design constraint for us, coaching data never feeds the summative evaluation.
Kraft & Gilmour (2016), on developmental vs. summative observation.
Estimates of what it costs to replace a teacher commonly range from roughly $10,000 to $25,000, depending on district context and how the cost is measured, in recruiting, hiring, and lost productivity. That's the number behind our retention ROI calculator, and the reason retention, not just compliance, is the point.
District replacement-cost studies (Learning Policy Institute and others).
See how the evidence shows up in the product, on your district's numbers.