Shipping a product always involves making tough calls. Some of these interesting decisions relate to questions that may seem minor. One such question is the “green up arrow” question we dealt with for the iPhone Economy app (download from the app store)
The iPhone Economy app displays the latest values for several key economic indicators (e.g. housing, employment, trade deficit, inflation etc.) and draws graphs tracking the history of these indicators over the past few months, years and decades.
The app also compares the latest value of each indicator (e.g. housing starts) with its value from the previous month and the previous year. To make this comparison easy on the eye, we decided to add a green-up-arrow indicator if the latest value was more than the previous month’s value and a red-down-arrow if the value was lower than that of the previous month. See picture (at the bottom of this post) for an example of the UI.
Originally, this seemed like a good idea, but it raised a usability question. The app includes indicators like “unemployment rate”. Showing a green up-arrow for an increase in unemployment didn’t seem like a good idea because a green up-arrow would signify “good” to most people, but very few people would consider an increase in unemployment as good. So here are the options we considered
- No arrow to indicate increase/decrease, just a sentence that mentioned the increase or decrease.
- Using the same color to indicate increase and decrease (with an up arrow indicating increase and a down arrow indicating decrease)
- Using a green up-arrow for indicating a “good” increase (like an increase for the GDP parameter) and using a red up-arrow for a “bad” increase (like an increase in the unemployment rate)
- Using a green up-arrow for all increases and a red down-arrow for all decreases.
Option-1 seemed a bit user-unfriendly because it was limited to text. Option-2 was better, but using the same color meant that the up and down arrows were less easily distinguishable.
Option-3 had a couple of disadvantages. It introduced a minor inconsistency because some indicators would show increases with a green up-arrow and some others with a red up-arrow. More importantly, it introduced a judgmental element that wouldn’t necessarily be correct. For instance, is it “good” for the interest rate to go up or for imports to go up or for the dollar to become stronger? Arguably, sometimes it is good for some of these values to increase and sometimes it is good for these values to decrease. Option-3 also required some (minor) additional development work.
Given all of the factors discussed above, we decided to go with option-4 in spite of the usability question mentioned earlier. It will be interesting to find out whether users would have preferred one of the other options. However, as discussed in an earlier post on product design, startups need to make quick decisions and execute and ship quickly. So executing on option-4 was the best option for the app.