The dressmaker and tailor are careful not to array stout persons in checks and plaids, but try to convey an impression of sylph-like slenderness through the use of vertical lines. On the other hand, you have doubtless noticed in recent years the checkerboard and plaid-covered boxes used by certain manufacturers of food products and others to make their packages look larger than they really are. The advertiser who understands sensory illusions gives an impression of bigness to the picture of an article by the artful use of lines and contrasting figures. If his advertisement shows a picture of a building to which he wishes to give the impression of bigness, he adds contrasting figures such as those of tiny men and women so that the unknown may be measured by the known. If he shows a picture of a cigar, he places the cigar vertically, because he knows that it will look longer that way than if placed horizontally. [Sidenote: _Making an Article Look Big_] A subtle method of conveying an idea of bigness is by placing numbers on odd-shaped cards or blocks, or on any blank white space. The object or space containing the figures always appears larger than the corresponding space without the figures. This fact has been made the basis of a psychological experiment to determine the extent to which a subject's judgment is influenced by suggestion. To perform this experiment cut bits of pasteboard into pairs of squares, circles, stars and octagons and write numbers of two figures each, say 25, 50, 34, 87, etc., upon the different pieces. Tell the subject to be tested to pick out the forms that are largest. The susceptible person who is not trained to discriminate closely will pick out of each pair the card that has the largest number upon it. [Sidenote: _Testing the Confidential Man_] This test can be made one of a series used in examining applicants for commercial positions. It can also be used to discover the weakness of certain employees, such as buyers, secretaries and others who are entrusted with secrets and commissions requiring discretion, and who must be proof against the deceptions practiced by salesmen, promoters and others with seductive propositions. [Sidenote: _Tests for Credulity_] This examination can be carried still further to test the subject's credulity or power of discrimination. What is known as the "force card" test was originally devised by a magician, but has been adopted in experimental psychology. Take a pack of cards and shuffle them loosely in the two hands, making some one card, say the ace of spades, especially prominent. The subject is told to "take a card." The suggestive influence of the proffered card will cause nine persons out of ten to pick out that particular card.