An Apple-hired expert today argued that lots of consumers can't tell the difference between the iPhone and Samsung phones, or between the iPad and Samsung tablets. The expert witness, Kent Van Liere, polled consumers to see if they could distinguish between Apple's devices and Samsung's, finding that a significant number could not.

Apple argues that its "trade dress," the distinctive look of the iPhone and iPad—from their sizes and shapes to the design of their home screens and icons—has been violated by Samsung's various competing products. As such, Apple is trying to prove that Samsung created products so similar to the iPhone and iPad that people look at Samsung devices and assume they were made by Apple.

In addition to Van Liere's comparison study, Apple trotted out expert witness Hal Poret, who surveyed 582 people who had purchased mobile phones in the past year or were likely to purchase one in the next 12 months. Poret found that consumers widely recognize the iPhone and iPad trade dress and associate it with Apple.

Samsung attacked the credibility of the studies, saying they were biased in favor of Apple. Apple may finish arguing its case by Monday, after which Samsung can mount its defense.

According to a Bloomberg report today, Van Liere said there is a "substantial portion of consumers who are likely to be confused when they see” that Samsung products look similar to Apple ones. That's the kind of point Apple has been making in exhibits like this one:

Many of the findings in the Poret and Van Liere studies are cited in a report filed by another Apple expert witness named Russell Winer (Scribd link). In the Van Liere study, "over half of respondents (52%) who were shown pictures of a Samsung Galaxy Fascinate phone associated the look and design of the Samsung Galaxy Fascinate with an iPhone, or a phone or product manufactured by Apple," Winer wrote. Meanwhile, only 14 percent of respondents associated an unnamed "control device" with Apple products.

As for tablets, "the survey evidence from the Van Liere Report illustrates the similarity between the look of Samsung Galaxy 10.1 tablet and that of the iPad," Winer wrote. "When shown a video of a Samsung Galaxy 10.1 tablet, 43% of respondents indicated that the tablet was an iPad or Apple product. On the other hand, only 24% of respondents indicated that the 'control' tablet was an iPad or Apple product."

Poret's study tries to show that the iPhone and iPad are so distinctive that people continued to associate their general looks with Apple long after near-identical products hit the market. "The Poret Report contains results from a June 2011 survey that shows that the distinctive look of the iPhone remained a strong source identifier for Apple nearly a year after Samsung released the first of its accused products," Winer wrote. "68.0% of respondents who were shown a disguised image of an iPhone 3G—with the icons on the face of the phone blurred and the 'home' button covered with a sticker—still identified it with Apple, iPhone, or a similar Apple-related product name."

Samsung attorney Bill Price poked holes in the Apple witnesses' research. The "control product" tested against the Galaxy Tab 10.1 was Barnes & Noble's Nook Color. Price said the control product shouldn't have been a device viewed by many as an e-reader, when Apple could have used a Motorola or LG tablet instead, according to a CNET report from the courtroom. Samsung also criticized the study for showing people video of tablets rather than the physical devices themselves, with the video showing only the front and side views of the devices, according to Forbes.

Testimony today also featured an Apple-hired expert who testified that Samsung stole Apple's patented "rubber band" or "bounce-back" technology, referring to touchscreen scrolling in which the screen snaps back into place after a finger has pulled the screen as far as it can go and then is lifted off the screen. This is one of numerous features claimed by Apple in a US patent filed in December 2007 on "List scrolling and document translation, scaling, and rotation on a touch-screen display."

For this argument, Apple brought out University of Toronto Computer Science Professor Ravin Balakrishnan, who testified that the rubber band effect is an Apple innovation that prevents user confusion, which could be caused when a user doesn't know where an image or document ends.

Balakrishnan reportedly testified that 21 Samsung devices violate the Apple patent.

Balakrishnan has billed Apple $500,000 for being an expert witness in nine cases, according to a Mercury News live blog of the trial. The blog notes that Samsung attorney Kevin Johnson got Balakrishnan to admit that it's possible to perform the bounce effect without violating Apple's patent, although it would be difficult. Samsung also showed video of various Samsung devices in which the rubber band effect is not used in all applications.

In making its argument, Apple pointed to Samsung's own internal documents, which compared Samsung products to Apple's and referenced the bounce-back effect, according to a CNET story.

Showing Samsung's internal analyses of its own products compared to Apple's has been a much-used tactic so far. If you want to see more of the pictures and documents Apple has used to make its case, refer back to our story "Apple's case that Samsung copied the iPhone and iPad—in pictures."