Table 2.

SSM Effect Calculated Four Different Ways from the Same Data Set

References	Different SSM error calculations on low-salience targets in Adamo et al. (2019) data	Results of t-test	Trials that are filtered
Fleck et al. (2010)	Single-low hit rate compared to low hit rate on dual-target trials where a high was detected first or second	t = 5.10 p < .001 Cohen’s d = 0.93	Single: None Dual: Remove trials where high-salience target was not found
Cain et al. (2013)	Single-low hit rate compared to low hit rate on dual-target trials where a high was detected first	t = 8.95 p < .001 Cohen’s d = 1.63	Single: None Dual: Remove trials where high-salience target was not found and trials where low-salience target was found first
Adamo et al. (2019)	Matched single-low compared to low hit rate on dual-target trials where a high was detected first	t = 8.22 p < .001 Cohen’s d = 1.50	Single: Remove trials that do not match the dual-target trials included in the analysis Dual: Remove trials where high-salience target was not found and trials where low-salience target was found first
Becker et al. (2020)	Expected hit rate calculated from dual-target trials compared to low hit rate on dual-target trials where a high was detected first	t = 5.21 p < .001 Cohen’s d = 0.95	Single: Remove all single-target trials Dual: Keep all dual-target trials to calculate expected hit rate. Remove trials where high-salience target was not found and trials where low-salience target was found first to compare to expected hit rate

The data analyzed were used in Adamo et al. (2019) in a multiple-target search with high- and low-salience targets (see Fig. 1). A two-tailed, paired-samples t-test was used to analyze the data. Fleck et al. (2010) originally calculated SSM errors by comparing the hit rate for single-target trials of one target type (e.g., low-salience ‘T’) to the hit rate of the same type of target when a different type of target was found on dual-target trials (e.g., low-salience ‘T’ when a high-salience ‘T’ was detected; See Fig. 1 graph). Cain and Mitroff (2013) later restricted to instances in which the target of interest was not found first on dual-target trials (e.g., hit rate for a low-salience ‘T’ when a high-salience ‘T’ was detected first). Adamo et al. (2019) then suggested changing the methods to be more in-line with radiological methods and use matching displays—displays where single- and dual-target trials were identical in target and distractor identity and location with the exception that one of the two targets were removed in the single-target trials (see Fig. 1 search displays). They suggested restricting the SSM calculation to only include matched single- and dual-target trials (e.g., filter the dual-target trials where the high-salience ‘T’ was found first and compare the hit rate for the “second” low-salience 'T' to the hit rate on its matched single, low-salience display). Becker et al. (2020) recommended using only dual-target trials to calculate the expected hit rate for a specific target (e.g., low-salience ‘T’; See Eq. 1). This value is compared to the same type of target when a different type of target was found first on dual-target trials (e.g., hit rate for low-salience targets on dual-target trials when a high-salience target was detected first)