, hall-, . , . Monadic Test. , . , - ( , ).
, , Sequential Monadic Test. , , . , , , , .
Triangle Test. , . , . , , , , .
hall- . home- ( . home ). home- , (, ), (, ). home- , ( , , , ), (, ).
home-. . .
mystery shopping , . , . , , secret shopping, virtual customer.
, . . .
, (, , ) . . mystery shopping . e-mail.
, . , , . .