I think a concept some are still struggling with is this - the difference between the overall trend and the individual adjustments.
What have prices done in the past year? If prices have declined since this time last year, then the trend is declining. But, that does not mean that there will be negative market conditions on all the comps - maybe not on any of them.
Example: Suppose there was enough data for monthly analysis, and suppose that analysis, showed the following price trend:
July $400K
Aug $396K
Sep $392K
Oct $388K
Nov $384K
Dec $380 K
Jan $375K
Feb $375K
March $376K
April $374K
May $376K
June $376K
For all comps sold in the past 6 months it would be reasonable to say that the market in that time period is stable, and no adjustments are warranted.
At the same time, the trend on page 1 should be declining, because based on a minimum 12 month analysis the prices have declined.