Table 2

Average transaction times for coloured versus plain packs with evidence of a training effect and selection errors

ComparisonParticipant numbersMean (s)95% CIsMean difference (s)t Scorep Value
Coloured packs first
 Coloured packs 1st 50 transactions263.61±0.380.477.783* <.001
 Plain packs 2nd 50 transactions3.14±0.28
Training effects
 Transactions for both packs 1–25523.80±0.290.827.539* <.001
 Transactions for both packs 26–502.98±0.17
 Transactions for both packs 1–50523.39±0.210.4610.131* <.001
 Transactions for both packs 51–1002.93±0.18
Controlling for training effects
 Coloured packs 1st 50 transactions263.61±0.380.442.167 0.037
 Plain packs 1st 50 transactions263.16±0.16
 Coloured packs aggregated523.17±* 0.040
 Plain packs aggregated2.92±0.14
Selection errors
 Colour packs520.73 (errors)±0.310.519 (errors)2.558 0.011
 Plain packs0.21 (errors)±0.14
  • * Paired samples t test.

  • Independent samples t test.

  • z Score for Wilcoxon signed ranks test.