23.4Matching Dogs and Owners. Researchers constructed two testsheets, each sheet including 20 photos of the faces of dog-ownerpairs taken at a dog-lovers field festival. The 20 sets ofdog-owner pairs on the two sheets were equivalent with respect tobreed, diversity of appearance, and gender of owners. On the firstsheet, the dogs were matched with their owners, while on the secondsheet, the dogs and owners were deliberately mismatched. Threeexperiments were conducted, and in all experiments, subjects wereasked to “choose the set of dog-owner pairs that resemble eachother, Sheet 1 or Sheet 2,” and were simply told the aim of theresearch was a “survey on dog-owner relationships.” In the firstexperiment, the original sheets were shown to subjects; in thesecond experiment, just the “mouth region” of the owners wasblacked out in all the pictures on both sheets; while in the thirdexperiment, just the “eye region” of the owners was blacked out.Subjects were assigned at random to the three experimental groups,and in each experiment, the number of subjects who selected thesheet with the dogs and their owners correctly matched wasrecorded. Experimenters were interested in whether blacking outportions of the face reduced the ability of subjects to correctlymatch dogs and owners.⁸ Here are the results:

Experiment	Number of Subjects	Number Correctly Matched
Experiment 1	61	49
Experiment 2 (mouth blacked out)	51	37
Experiment 3 (eyes blacked out)	60	30

1. Is there evidence that blacking out the mouth reduces asubject’s ability to choose the sheet which correctly matches thedogs and their owners? Follow the four-step process as exhibited inExamples 23.4 and 23.5.
2. Is there evidence that blacking out the eyes reduces asubject’s ability to choose the sheet which correctly matches thedogs and their owners? Follow the four-step process as exhibited inExamples 23.4 and 23.5.
3. Contrast your conclusions in parts (a) and (b) in the contextof the problem using non-technical language.