Comparisons using the eyeball check

Back when I first started working, one of my duties every month was to check reports. Yes, I know it says “Systems Analyst” on my job title then. Thank you for pointing that out. Don’t new staff often take on all sorts of miscellaneous duties like that?

As I was saying, I was to check reports (some financial data was involved). The users would check them of course. We’re just checking them (the report generator program was written by us) before handing the reports to them. Basically, it’s to make sure the numbers tally for the sections that they’re meant to be the same.

Now the reports were PDFs. In order to save paper (and more importantly, not keep so much paper physically), I check them on the computer screen. My colleague taught me a simple trick. Use Alt-Tab.

Open the first report and maximise it on the screen. Open the second report and maximise it on the screen too. Then I Alt-Tab between the 2 reports, flipping rapidly to make sure the numbers were identical, then paging to the next on both report, and so on and so forth.

I’m not understanding the content of the page, I’m using visual recognition. As in that’s not really a zero that’s registering in my brain. More like a slightly vertically elongated circle. I’m not comparing words and numbers. I’m comparing pixels.

PDFs aren’t diff-able (at least not that I know of). And it turns out that comparing PDFs using the eyeball check is exceedingly simple (albeit manual and tedious) with the Alt-Tab trick. It’s like facial recognition. Humans are good at recognising faces. We haven’t gotten computers to do on par though…

P.S. In case you don’t know about Alt-Tab, on Windows (hi Mac user!), when you hold the Alt button and tap the Tab button, the window just before your current window pops up. So I open the first report, then open the second report. The first report is on the window just before the second report’s window. Alt-Tab once to bring the first report into focus, pushing the second report back. Repeated Alt-Tabbing simply cycles between the 2 most “current” of the windows, in our case, the 2 reports.