After a quick internet search I found this article. From that article:
While the number of contact hours ranged widely, from five to over 100 hours depending on the study, those initiatives that showed positive effects included 30 or more contact hours. It thus seems clear that effective professional development requires considerable time, and that time must be well organized, carefully structured, purposefully directed, and focused on content or pedagogy or both (Birman et al. 2000; Garet et al. 2001; Guskey 1999).
From my own experience helping lead professional development, I’d guess 30 hours is light. Colleagues & I are currently in the middle of a 120-hour year-long program and the tide is just starting to shift. However, the extent of change expected likely influences how long that change takes & I like to think I have pretty lofty goals.
My hope for 2016: for school districts to stop paying one-time speakers thousands of dollars & for one-time speakers to find a way to put in the time real change requires.
Teaching as Dynamic 
Why don’t you speak to these schools yourself, charging little:)
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Well, most recently I’ve written grants so the district doesn’t have to pay anything & we still did a long term program.
In the past, when a district has offered me X dollars for a single speaking engagement, I told them I’d only do it if they let me come at least 6 times, but I’d do the six for the price they wanted to pay for one.
I try to live by my own rules most of the time. ;-)
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Thanks for the link to the PDK article. I am planning to reference it in an upcoming column about initiative fatigue.
I noted you are in the midst of a 120 hour program. I can’t think of a way we could set aside 120 hours in my local district, although I agree 30 hours is probably too light. What are your thoughts on districts setting aside 50 hours (for example) over multiple years as one strategy to honoring “effective professional development requires considerable time..” ?
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I think it makes sense. The key there is keeping the 50 hours congruent. If those 50 hours are interspersed with other initiatives you are pulling people in too many directions. 30 hours is likely enough, if the message during those 30 hours is consistent.
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