My Selenium test structures goes as -

Data Object class -

public class RegistrationData {

  String firstName = "test first name";
  String lastName = "test last name";

  // Getter Setter Here 
}

Page Object class which carries out operations on a Web Page -

public class RegistrationPage {
   private RegistrationData regData;

   public void setRegistrationData(RegistrationData regData) {
   this.regData = regData();    

   public NewAccountPage fillRegForm() {
     enterFirstName("FirstNameTextBoxLocator", regData.getFirstName);
     enterLastName("LastNameTextBoxLocator", regData.getLastName);
     // Some more fields are filled here
     return NewAccountPage();
   }
}

And test class uses them as -

public class TestRegistration extends SelTestCase {

   @Test
   public void testRegNewUser() {
     RegistrationData regData = new RegistrationData();
     RegistrationPage regPage = New RegistrationPage();
     regPage.setRegistrationData(regData)
     regPage.fillRegForm();
     // Some assertion here
   }
}

Now since fillRegForm method does not take any argument, Can I assume that it is an example of loose coupling despite I need to set RegistrationData in RegistrationPage before being able to use fillRegForm method.