The very high-profile failure of a new app that was supposed to help report Iowa Caucus results has generated some important lessons. Even though the New Hampshire primary was not plagued by the same kinds of gross technical failures, it would be a mistake to just quickly move on and forget the lessons of the first debacle. As the Nevada Caucus approaches, it’s clear some lessons have been learned, but not all.

As is widely known now, the Iowa app technology was designed to help record results from rounds of caucusing and pull together the results from across the state. But the app didn’t work, and results were not delivered, raising questions about not just the technology but the implementation process for the system. Massive frustration and even conspiracy theories ensued.

Fortunately, Iowa had paper records and was able to turn to those in the face of the tech failure to help confirm the results. The media, candidates, and the public had to be patient, but without the paper records, results wouldn’t have been just delayed; they would have been impossible to obtain.

The first lesson is clear: Anything computerized can fail for a slew of reasons, from hacking to software defects to inadequate training of election workers. This includes tablets, voting machines, ballot scanners, electronic poll books, and apps on phones and tablets.

That is why a central tenet of the joint election protection work of the Brennan Center for Justice at New York University and Common Cause is to push states and counties to rigorously test equipment before it’s rolled out to voters, and to have backups for every critical part of the election, such as ballots, poll books, and voter registration databases. It’s important that officials have plenty of those supplies on hand so that they don’t run out, and to make sure workers understand how to use the backups.

When there’s a problem with technology in the voting process, having these measures in place can help to reassure the public even before all the facts can be discovered. Officials can say, “Don’t worry, the poll workers know they can resort to the paper poll book.” Or, in the case of a reporting problem, “Don’t worry, we’ll get this right because we can fall back on the paper records if we have to.”

In Nevada, it appears that the Democratic party has abandoned its planned use of the app that plagued Iowa — and is instead using paper ballots. That is an improvement. However, it’s unclear whether there will be appropriate backup measures in place for the check-in system if it fails.

Voting Equipment in Swing States

Currently all of the states that fit in the swing-state category have voting systems that produce a paper backup of a voter’s choice, that the voter can then review. Only eight states – New Jersey, Indiana, Louisiana, Texas, Kansas, Kentucky, Mississippi and Tennessee – now use paperless systems as primary polling place equipment in at least some counties and towns. These systems are impossible to manually audit, meaning electronic tallies simply can’t be checked. The computers must just be trusted.

The second lesson of Iowa is that paper ballots must be reviewed by hand during a post-election audit to check computer-generated election results. Faulty electronic tallies do not correct themselves. In an audit, election officials routinely sample and review enough paper ballots to generate confidence that the election results are correct.

In Iowa, the reporting problems were so clear that election officials had no choice but to review the paper records. But in this country, most election results are not double-checked using paper ballots, even where they exist. Even recounts of highly contested races often do not require manual checks.

Currently only two states – Rhode Island and Colorado — require manual audits that will consistently provide a high level of confidence that the software tallied the most votes for the true winner. Fortunately, election officials in a number of other states, including Pennsylvania, Ohio, and Michigan, have said they want to establish new manual checks on tallied results, which will ensure this high level of confidence. But that process can be challenging when funds and staffing are short.

Internet Voting

The third lesson of Iowa is “don’t forget the first two rules,” even when there’s a fancy new app or piece of technology that promises to make elections easier, like one that lets voters cast ballots on the Internet. With Internet voting, there is no paper ballot. The ballot is only digital and can be corrupted even if the vendor selling the app uses advanced cryptography. U.S. elections are a target, and foreign actors are spending billions to influence our election outcomes—how could voters ever be certain the encryption is good enough? Unfortunately, 32 states allow some class of voters to cast their ballots via email or through internet portals.

Americans deserve elections that give them confidence in the results. States can do their part by spending recently allocated money from Congress on paper backups and provisional voting supplies. They can also spend that money on manually checking paper ballots to make sure the reported outcomes are right.

Congress can do its part by providing consistent funding for this work. And the public can do its part, by being patient while election officials make sure that results are correct.

It can take time and effort to ensure that every vote is counted, and to check the paper records to see that it was done right. In elections, accuracy is more important than speed.

IMAGE: Carl Voss, Des Moines City Councilman and a precinct chair, returns to his car after he unsuccessfully attempted to drop off a caucus results packet from Precinct 55 at the Iowa Democratic Party headquarters February 4, 2020 in Des Moines, Iowa. The announcement of the results in the Iowa presidential caucuses were delayed after “inconsistencies” were found related to the app used to count the votes. The state Democratic Party verified results manually before releasing results. (Photo by Alex Wong/Getty Images)