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POWER SIMULATION -- unmerge_d0_13   [metric: # successes (count)]
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model: behavior ~ stim + day + stim:day + (1|rat)   (behavior = # successes (count); day within-window)
observed groups: stim n=3, control n=3   nrep=120, alpha=0.05
ground truth: stim:day=+1.547/day, rat SD=0, residual SD=14.68, days=14

 true stim:day interaction = +1.547 (100% of observed)
  N/group  | per-animal power | LME power
  ------------------------------------------
  3        |  0.22            |  0.56  <- observed
  5        |  0.53            |  0.69
  8        |  0.82            |  0.88
  12       |  0.97            |  1.00
  16       |  0.98            |  0.98
  24       |  1.00            |  1.00

 true stim:day interaction = +0.7733 (50% of observed)
  N/group  | per-animal power | LME power
  ------------------------------------------
  3        |  0.12            |  0.22  <- observed
  5        |  0.21            |  0.23
  8        |  0.42            |  0.43
  12       |  0.50            |  0.52
  16       |  0.64            |  0.71
  24       |  0.78            |  0.74

Read the per-animal column as the honest power; LME is optimistic (obs-level DF).