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Table 1 Measures of search performance by group with statistical comparisons

From: Great expectations: minor differences in initial instructions have a major impact on visual search in the absence of feedback

Experimental measure Low-expectation group High-expectation group Statistical comparison
Total search time    
Hard single-target misses 9.43 s (2.12 s) 13.74 s (2.40 s) Z = 6.34; p < 0.001
Easy single-target misses 9.60 s (2.15 s) 13.35 s (2.70 s) Z = 5.41; p < 0.001
Hard single-target hits 9.56 s (1.61 s) 9.03 s (1.58 s) Z =  − 1.27; p = 0.20
Easy single-target hits 8.88 s (1.54 s) 8.43 s (1.70 s) Z =  − 1.12; p = 0.26
Timeout rate    
Hard single-target trials 4.72% (6.76%) 11.99% (6.74%) Z = 4.95; p < 0.001
Easy single-target trials 2.46% (2.86%) 4.35% (3.82%) Z = 2.73; p < 0.01
Dual-target trials 1.35% (2.72%) 1.17% (1.43%) Z = 1.23; p = 0.22
Hit rate    
Hard single-target trials 70.33% (11.67%) 82.56% (9.87%) t(82) = 5.20; p < 0.001
Easy single-target trials 90.97% (7.02%) 94.46% (4.56%) t(82) = 2.73; p < 0.01
Hard (dual-target trials) 64.89% (12.95%) 64.85% (15.38%) t(82) =  − 0.10; p = 0.92
Easy (dual-target trials) 88.05% (7.16%) 86.80% (7.01%) t(82) =  − 0.81; p = 0.42
Dual-target: Both Hit 56.16% (14.23%) 53.09% (18.76%) t(82) =  − 0.84; p = 0.41
Hit response time    
Hard single-target trials 5.40 s (0.84 s) 5.93 s (0.88 s) t(82) = 2.80; p < 0.01
Easy single-target trials 3.28 s (1.02 s) 3.43 s (1.15 s) t(82) = 0.64; p = 0.52
False alarm rate    
Hard single-target trials 3.16% (6.46%) 5.84% (7.04%) Z = 2.78; p < 0.01
Easy single-target trials 2.88% (6.65%) 3.30% (4.34%) Z = 1.79; p = 0.07
Dual-target trials 2.31% (4.49%) 2.31% (3.04%) Z = 0.39; p = 0.70
  1. Significant differences between groups are indicated in bold italics