Ranking Facts Game

About Sort Order

Sort Order gives you three to six items and asks you to put them in order. You tap them one at a time, starting with the lowest value and ending with the highest. The question says what to order: mountains by height, buildings by height, animals by top speed, rivers by length, historic events by date or countries by population.

The number of items grows from three on level 1 to six on level 10, and the gaps between the values shrink. In the beginning the values are at least twice as far apart, and at the end only about 23 percent. Countries by population join the pool from level 3. There is partial credit for a mostly correct order.

How to play

1. Read the question: it tells you what to order and in which direction.
2. Think about the lowest item and tap it first. A number appears on each item that you have tapped.
3. Continue to the highest item. The round ends after the last tap.
4. The result shows the correct order, and you earn points for every pair you ranked right.

Tap the items one by one, starting with the lowest value and ending with the highest. The score is the share of pairs you ranked correctly.

How scoring works

The score is the share of pairs of items that are in the right order relative to each other. With four items there are six pairs, so one swapped neighbour costs about 17 points. A perfect order scores 100; a completely reversed order scores 0. If time runs out, the score is based on the items already tapped.

The items are drawn from the same tables as Higher or Lower, plus 40 countries by population. The minimum gap between any two values is a factor of 2 on level 1 and about 1.23 on level 10; for dates it is 45 years on level 1 and 10 years on level 10. You have 12 seconds plus 3 seconds per item.

What it trains

The game trains ordinal thinking, the ability to place things on a scale relative to each other. It covers general knowledge of sizes, speeds and dates, and the habit of checking each item against its neighbours.

It also teaches you to use the position of an item in a series, which is a good way to reason when you do not know exact values.

Tips for a higher score

• Begin with the items you are most sure about: the lowest or the highest of the set.
• Find the two items that are closest to each other and ask which of them is higher. The rest of the order can often be filled in around them.
• Use anchors: know three or four values for each kind and place new items in between.
• If you are unsure about two neighbours, tap them in the order you think most likely. A single swap costs fewer points than a big error.
• Do not rush. The round has a fairly generous time limit, since every item needs a tap.

The idea behind it

Ordering items along a dimension is a core skill in numerical cognition. Studies of the mental number line, like the work of Stanislas Dehaene and colleagues in the 1990s, found that people compare numbers faster when they are far apart than when they are close, the numerical distance effect, which is why the game makes the gaps smaller on higher levels.

The score used here, the share of concordant pairs, is closely related to Kendall's tau, a measure of rank correlation introduced by Maurice Kendall in 1938. It has the useful property that one misplaced neighbour changes the score much less than a completely wrong order.

Related games

Free, no account. Your best scores are saved on your device.