The reported laboratory study is the part of empirical project concerning the variables influencing the accuracy of polygraph examination. The authors carried out an experiment on 51 participants. They were divided in two groups. 27 of them were concealing their knowledge about a particular feature of the case under examination. 24 of them had not got to know about
it. Each group was divided in two parts yet – depending on the manner of question presentation (verbal or as a picture). Each examination included three tests. Every participant’s reactions were organized according to their significance (the size of GSR reactions were taken into consideration). The authors compare the accuracy outcomes of particular groups. The experiments
confirmed author’s original hypothesis about influence the manner of question presentation
on the accuracy of polygraph examination.