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POWER SIMULATION -- unmerge_d0_5   [metric: success RATE]
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model: behavior ~ stim + day + stim:day + (1|rat)   (behavior = success RATE; day within-window)
observed groups: stim n=3, control n=3   nrep=120, alpha=0.05
ground truth: stim:day=+0.04902/day, rat SD=0.04642, residual SD=0.07858, days=6

 true stim:day interaction = +0.04902 (100% of observed)
  N/group  | per-animal power | LME power
  ------------------------------------------
  3        |  0.52            |  0.89  <- observed
  5        |  0.92            |  0.97
  8        |  1.00            |  1.00
  12       |  1.00            |  1.00
  16       |  1.00            |  1.00
  24       |  1.00            |  1.00

 true stim:day interaction = +0.02451 (50% of observed)
  N/group  | per-animal power | LME power
  ------------------------------------------
  3        |  0.12            |  0.34  <- observed
  5        |  0.40            |  0.48
  8        |  0.62            |  0.72
  12       |  0.82            |  0.87
  16       |  0.94            |  0.95
  24       |  0.99            |  0.99

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