Apple Inc. continued its push to convince a jury that Samsung Electronics Co. copied its products, turning to a graphical designer who once worked at Apple.

Susan Kare, a independent graphics specialist who created images used in Apple's original Macintosh computer, testified Tuesday that she had analyzed Apple and Samsung's phones and found elements of their interfaces to appear 'substantially similar.'

She noted that the home icons, or images that depict applications on the device's screens, used for the Samsung phones such as the 'Captivate,' 'Epic 4G' and 'Galaxy S 4G' had infringed an Apple design patent that covers the look of and design of the iPhone's home screen. The iPhone uses a grid of images with text beneath them to represent applications on its home screen.

Ms. Kare said that she had even become confused herself, once picking up a Samsung phone off a table full of devices at one of the lawyer's offices when she wanted to make a point about the iPhone.

'I mistook one for the other,' she said. 'In addition to the analysis, I personally had the experience of being confused.'

Samsung lawyers, in their cross-examination of Ms. Kare, focused on the start-up process for a Samsung phone, including when it initially says 'Samsung' on the screen, shows an animated 'Droid' advertisement and then a home screen with a Google Inc. GOOG -0.35% search bar at the top. Customers then have to push a button for the phone to display the familiar grid that Apple claims infringes its design. Google supplies the Android software used in Samsung smartphones cited in the case.

Samsung's lawyer, Charles Verhoeven, asserted that in the process for getting to the application screen