Editor's note: Amy Gahran writes about mobile tech for CNN.com. She is a San Francisco Bay Area writer and media consultant whose blog, Contentious.com, explores how people communicate in the online age.
(CNN) -- There's a learning curve for every new consumer technology -- both for people who use the device and for makers of software or services that run on it. This has definitely been the case for Apple's iPad, which hit the market just over a year ago.
According to new research from Nielsen Norman Group (NNG), the usability of iPad apps and of Web sites displayed on this device have improved substantially in the past year. In particular, "apps have become more consistent and standardized, making them easier to use," NNG said.
But there's still plenty of room for improvement.
NNG brought in 16 people with at least two months' experience using the iPad and systematically tested how they interacted with 26 iPad apps and six Web sites.
Here's what they learned, based on users' feedback, preferences and complaints:
Touchable areas are often too small, too close, not easy enough to discern.
Often, text content is big enough to read, but links in the text are too small to tap easily. Similarly, sites and apps that have too many touchable areas too close together increase the risk of touching the wrong one.
This leads to navigational accidents, which can be especially vexing in iPad apps that lack a "back" button. Also, many touchable areas don't look obviously touchable, so users tend to miss them.
Similarly, "swipe ambiguity plagued users when multiple items on the same screen could be swiped. Carousels often caused this usability problem in apps that also relied on swiping to move between pages. Many users couldn't turn the page because they swiped in the wrong spot. Their typical conclusion? The app is broken."
iPad users dislike typing on the touchpad.
This presents a variety of issues, including that fewer iPad users are likely to go through a registration process that requires lots of onscreen typing. This may partly explain why the iPad has a reputation at being not so great for media creation. "(iPad use is) heavily dominated by media consumption, except for the small amount of production involved in responding to e-mails."
The Web browser has its limits.
It's good for simpler tasks, not so good for complex tasks. NNG's advice: "If your service requires substantial interaction, consider an app instead of a site."
In contrast, simpler tasks tend to work well in the iPad browser: "In our testing, a few tasks were performed both on the Web and using an application. In these cases, our participants were always successful on the Web. A third of the corresponding tasks that involved apps ended in failure." Usually, this was because the Web site contained more information than the app, or the app design was confusing.
NNG noted: "Whenever apps lack features, users quit them for the websites."
Use of screen space is inefficient.
"Many apps use the (relatively) big iPad screen inefficiently: the screen contains little information, and users have to take extra actions to get to the content."
Also, "Popovers are frequent culprits for underutilizing (screen) space. Too often we see relevant content crammed in a small popover window, while all the other space underneath remains unused."
People prefer landscape mode, barely.
"Slightly more users mentioned that they preferred the landscape (horizontal) orientation for the iPad. A seemingly related factor was whether they were using an iPad cover; those who did mentioned that they often propped their iPad up in landscape orientation."
One problem NNG noted was that some iPad apps handle navigation differently depending on orientation: "For instance, they use horizontal navigation in landscape and use vertical navigation in portrait." This can confuse users.
Some apps even offer different content depending on orientation. For instance, BBC News' app lists different sections in landscape and in portrait orientation. This is especially likely to confuse or annoy users, since users are more likely to switch orientations in a single session while in magazine or news apps.
iPad users are more leisurely about kill time.
"Killing time is the other major use for smartphones, and that is shared with the iPad. ... (However,) the uses are slightly different. The time that is usually available on the smartphone is much shorter and more fragmented than the one available on the iPad.
"On the smartphone, users may look for a quick article to kill the three minutes of waiting for the train; once on the train, they may take out the iPad for the hour it takes them to ride home. As one user put it: 'I am not in a rush when I use this device.' "
Die, splash screens, die.
"We thought we had driven a stake through splash screens many years ago and eradicated them from the Web, but apparently splash screens are super-vampires that can haunt users from beyond the grave. Several new iPad apps have long introductory segments that might be entertaining the first time, but soon wear out their welcome. Bad on sites, bad in apps. Don't."
The opinions expressed in this post are solely those of Amy Gahran.