Famous aphorism, which originates from 1976, was mentioned by George Box when referring to statistical models. I find “All models are wrong, but some are useful” to be applicable to all the models in our lives, but especially to how we’re supposed to raise our kids. Internet is full nowadays of guides about everything you need to know to raise a child. You’ll find in this article the most important mental and physical baby/toddler development info, so bookmark this page! (Note: I participate in the affiliate amazon program. This post may contain affiliate links from Amazon or other publishers I trust (at no extra cost to you). I may receive a small commission when you buy using my links, this helps to keep the blog alive! See disclosure for details.) Understanding Growth Standards for Children The WHO Child Growth Standards were developed using data collected in the WHO Multicentre Growth Reference Study by the World Health Organisation. The site presents documentation on how the physical growth curves and motor milestone windows of achievement were developed as well as application tools to support implementation of the standards. The below growth curves can guide you in the first 2 years of age: Tracking Your Child’s First Major Gross Motor Milestones As a first time parent I was concerned about how soon my baby girl managed to achieve the major motor milestones. The below chart sums up a comprehensive study by the World Health Organization. You’ll see that the windows of achievement are wide, there is no reason to be concerned if your baby is inside the window. Reference: WHO Multicentre Growth Reference Study Group. WHO Motor Development Study: Windows of achievement for six gross motor development milestones. Acta Paediatrica Supplement 2006;450:86-95. Tracking Mental Development Milestones in Children I’ve mapped below the first 3 years of mental development milestones based on 3 famous books: The Wonder Weeks: A Stress-Free Guide to Your Baby’s Behavior Misbehavior is Growth: An Observant Parent’s Guide to the Toddler Years Misbehavior is Growth: An Observant Parent’s Guide to Three Year Olds The Wonder Weeks: 10 major, predictable, age-linked changes – or leaps – during their first 20 months of babies’ lives: Below is what Amber Domoradzki observed as childhood developmental stages: Creating a Healthy Sleep Schedule for Your Baby I really like how Dr Marc Weissbluth advises In his book Healthy Sleep Habits, Happy Child, 5th Edition: A New Step-by-Step Guide for a Good Night’s Sleep to “watch your child, not the clock”, but still tells you to try and stick to a sleep schedule. A schedule will help you obtain healthy sleep patterns. You’ll baby will give you signs when she/he will be ready to have the sleep schedule adjusted. I shared my experiences with sleep training in this article: https://thebabydatascientist.com/2-successful-sleep-training-methods-to-try/ Navigating Sleep Regressions in Infants and Toddlers Sleep regressions; I’m not sure how real they are, but be aware that they might happen: A Step-by-Step Guide to Introducing Solids to Your Baby’s Diet Introducing solids: the cheatsheet of baby food by months. You’ll find details in this article: https://thebabydatascientist.com/introducing-solids-the-cheatsheet/ Immunization Schedule for Children 0-15 months old: Find below immunization recommendations by the Centers for Disease Control and Prevention (CDC) for Ages 15 months old and younger . Some countries might provide the below vaccines for free based on the national vaccination schema: Encouraging Independent Play in Children Solo play is encouraged and beneficial, but how long can our babies / toddlers play by themselves? at 6 months up to 5 minutes at 12 months 10 to 15 minutes at 18 months up to 20 minutes at 24 months up to 30 minutes A full article on this here: https://thebabydatascientist.com/independent-play-6-to-24-months/ OMG Are they all wrong? Well yes, it will not be 100% applicable to your child. Still, they’re useful. It’s reassuring to know what to expect and that difficult periods are normal.