Mistaken Data

2 posts
Algorithm leads to arrest of the wrong person

Even though there was supposedly a person in the decision-making process and a surveillance photo wasn’t actually Robert Julian-Borchak Williams, he still ended up handcuffed in front of his own home. Kashmir Hill reporting for The New York Times: This is what technology providers and law enforcement always emphasize when defending facial recognition: It is only supposed to be a clue in the case, not a smoking gun. Before arresting...

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Face depixelizer with machine learning, and some assumptions

In crime shows, they often have this amazing tool that turns a low-resolution, pixelated image of a person’s face to a high-resolution, highly accurate picture of the perp. Face Depixelizer is a step towards that with machine learning — except it seems to assume that everyone looks the same. There might still be some limitations. Tags: bias, face, pixels

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Bad bar chart

Welcome to whose bar chart is it anyway: where the geometries are made up and the numbers don’t matter. [via @dannypage] Tags: annotation

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Bad denominator

With coronavirus testing, many governments have used the percentage of tests that came back positive over time to gauge progress and decide whether or not it’s time to reopen. To calculate percentage, they divide confirmed cases by total tests. The denominator — total tests — often comes from the CDC, which apparently hasn’t done a good job calculating that denominator, because not all tests are the same. Alexis C. Madrigal...

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Poor comparison between two bar charts

A chart from Business Insider makes a poor attempt to compare the death rates, by age, for the common flu against Covid-19: The age groups on the horizontal axes are different, so you can’t make a fair side-by-side comparison. For example, the flu chart has a 50-64 age group. The Covid-19 chart has a 50-59 group and a 60-69 group. Ann Coulter’s interpretation of the chart might be worse than...

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Misinterpreted or misleading fire maps

With all of the maps of fire in Australia, be sure to check out this piece by Georgina Rannard for BBC News on how some of the maps can easily be misinterpreted when seen out of context. Tags: BBC, fire

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Study retracted after finding a mistaken recoding of the data

A study found that a hospital program significantly reduced the number of hospitalizations and emergency department visits. Great. But then the researchers realized that the data was recoded incorrectly, and the program actually increased hospitalizations and emergency department visits. Not so great. They retracted their paper: The identified programming error was in a file used for preparation of the analytic data sets for statistical analysis and occurred while the variable...

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The ‘impeach this’ map has some issues

Philip Bump explains why the “impeach this” map is a bit dubious: By now, this criticism of electoral maps is taught in elementary schools. Or, at least, it should be. Those red counties in Montana, North Dakota, South Dakota and Wyoming, for example, are home to 1.6 million 2016 voters — fewer than half of the number of voters in Los Angeles County. Trump won 1 million votes in those...

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NOAA chief scientist highlights the forecast contradiction

In regards to the press release that seemed to contradict the National Weather Service forecast, Craig N. McLean, chief scientist of NOAA: During the course of the storm, as I am sure you are aware, there were routine and exceptional expert forecasts, the best possible, issued by the NWS Forecasters. These are remarkable colleagues of ours, who receive our products, use them well, and provide the benefit of their own...

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Why you shouldn’t use ZIP Codes for spatial analysis

For Carto, Matt Forrest explains why you shouldn’t use ZIP codes for spatial analysis: The problem is that zip codes are not a good representation of real human behavior, and when used in data analysis, often mask real, underlying insights, and may ultimately lead to bad outcomes. To understand why this is, we first need to understand a little more about the zip code itself. In a nutshell, ZIP Codes...

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