Oracle Heuristic: Consistency Within the Product

Today brings an example of applying of the *consistency within the product* oracle heuristic. (You can read more about that here and here https://www.developsense.com/blog/2012/07/few-hiccupps/)

For reasons known only to the gods, when I visit AirBnB today, it insists on quoting all prices in Chilean pesos (CLP).

At today’s rates, the Chilean peso is roughly 600 to the Canadian dollar, so a property that might cost CAD200 per night displays as $120,000. The symbol for Chilean pesos is $, just like the US and Canadian dollar, so that adds to the alarm and confusion until I notice the CLP after the “dollar” figure. So at least there’s an explanation for the crazy-looking prices.

After a brief poke around the site, I find Account / Global Preferences. I set the preferred currency to Canadian dollars and press Save. But the problem persists! When I return to the home page, the prices are in Chilean pesos again; and global preferences indicates that my default setting is CLP. I’ve never made that selection, never booked from Chile, and (as yet) I’ve never visited Chile or tried to make a booking there. There’s no reason I can imagine for the CLP selection, other than a bug and data corruption.

Here’s the picklist for the currencies:

Is this an indexing problem; an off-by-one error, I wonder? Nope; it seems that when I choose another currency (like the Euro) and save, I don’t get one of the options on either side of it (the Emirati dirham or the Hong Kong dollar); it shows as Euros here. Yet when I go to the AirBnB home page, we’re back to Chilean pesos again. Refreshing the page doesn’t make a difference. Logging out and back in doesn’t make a difference. And when I return to the Global Settings page, the currency preference is back to Chilean pesos. I set try setting it to Euros again, save and browse around the site. Prices are still in CLP everywhere.

Deleting the cookies, clearing the cache, and then clicking on an icon for the home page brings me to the AirBnB home page. At this point, I’m not logged in, and I see a list of properties whose prices are rendered in Canadian dollars. Hurrah! But when I go to check Account/Global Preferences, my preferred currency is still listed as being Euros!

In summary, the product is showing a setting in one state, but displaying data as though that setting were in a different state. That is, the product is showing inconsistency within itself, the first P in FEW HICCUPPS.

As testers, we don’t need requirements documents or specifications to identify problems. Those things might help to reveal specific inconsistencies, but they’re not required to notice other problems.

What is required to recognize problems, whether our observation is mediated by tools or not, is the attention and engagement of the tester. Many problems won’t be noticed until we try to use the damned thing.