The Sleep Probability chart in our baby sleep tracker uses a gray scale to display the probability of your child being asleep at a certain time of day for the selected dates. Areas of high contrast (black and white) mean your child is on a predictable schedule. Areas of low contrast (light, middle and dark gray) mean a less regular schedule. A uniformly gray chart would mean a completely random sleep schedule.
Sleep Probability Chart for a Newborn (birth to 1 month)
6 Months Old
12 Months Old
Essentially, this chart shows your child’s sleep schedule by compressing daily sleep charts into one image. This kind of compression is extremely good at showing how patterns form and evolve over time. For example, it can help you identify the average bedtime or realize that your child is transitioning from 3 naps/day to 2 naps/day.
The number of gray scale values depends on the number of days in your chart. If you have two days in your chart, then there will be three colors: black, 50% gray and white. The reason is that the different possibilities for being asleep at a given time for the two days would be:
2/2 (100% – asleep both days at a given time),
1/2 (50% – asleep one day, not the other at a given time) and
0/2 (0% – asleep neither day at a given time)
The more days in your sample, the more possible gray scale values. So if you have a months worth of data (31 days max), there will be 32 shades of gray:
(0/31 through 31/31). This would be approximately 0% black, 3% black, 6% black, 10% black, etc…
(What? You’re not using our baby sleep tracker? It’s easy to create these cool charts for your baby. Discover Trixie Tracker and sign up for the Free Trial today.)
Related links: this chart was first seen on the Trixie Update in March 2004.