🧠 Free test Skip to content

What Is a Z-Score?

A z-score says how many standard deviations a result sits from a group mean: (score − mean) / SD. IQ deviation scores are a dressed-up z on a 100/15 scale — but only when the test was actually normed. Typing a web-game total into that formula does not manufacture a clinical IQ, because you still lack the real mean, SD, and sample that the formula assumes.

IQ Test › What Is a Z-Score?
📌 Key takeaways
Practice games:⏹️ Pattern Matrices Lite — 8 Original Items➗ Mental Math Speed Test⚖️ Dot Compare Lite — Which Cloud Has More

How do I compute z?

z = (X − μ) / σ, where μ and σ come from the same defined population as X. Using a made-up μ from a blog is not psychometrics.

How does that become IQ 100/15?

IQ ≈ 100 + 15z when the battery was scaled that way. The 15 is a convention, not a law of nature, and it does not apply to unnormed toys.

What is a percentile versus a z?

A percentile is a rank. A z is a location on a bell if the distribution is roughly normal. Ranks do not require normality; z-to-IQ conversion usually assumes it.

Can I z-score my dot-compare-lite hits?

You can subtract any number you like. Without a documented μ and σ for that exact task, the z is decorative, not a clinical IQ.

What about negative z?

It only means below that group’s mean. It is not a defect label. Web games should not be used to rank children or job applicants.

Where can I practice related ideas?

Mental-math for arithmetic comfort; pattern-matrices-lite as a puzzle. Neither outputs a valid z against a published manual.

🧠 Measure Your Own IQ →

❓ People also ask

What Is Attention Control?

Attention control is the skill of holding a current goal and filtering noise — a side conversation, a flashing tab, or a flanking arrow on a screen. It overlaps working memory and inhibition, yet it is not a synonym for IQ, and a browser hit count is not a diagnosis. Labs time tightly controlled trials; this site offers lite practice only, with no clinical battery behind the score.

What Is Attention Control? →
IQ and Income

Surveys often find a positive correlation between cognitive-test scores and later earnings, but the path is noisy: education, health, networks, discrimination, and luck all sit in between. A correlation is not a paycheck forecast, and a higher score on a web game here is not a raise, a credential, or a clinical IQ. Group charts never tell you one person’s worth or hiring outcome.

IQ and Income →
Visuospatial vs Verbal

Cognitive batteries often split visuospatial puzzles from verbal ones so you can see different strengths, not a single destiny. A high spatial sketch and a high vocabulary can diverge; neither pattern is a diagnosis. Online letter-span or hidden-figures lite games sample a slice of those families — they are not Wechsler indexes, not clinical IQ composites, and not career oracles.

Visuospatial vs Verbal →
What Is Cognitive Flexibility?

Cognitive flexibility is the ability to update a rule when the world changes — switching from color to shape, or from one task set to another, without staying stuck. It is one executive-function toy, not a full intelligence profile. Task-switch lite on this site is original practice with no age norms, no standard error, and no clinical IQ attached to the hit count.

What Is Cognitive Flexibility? →
Test Norming Basics

Norming is how a published test turns a raw hit count into a number you can compare with a reference group of the same age. Without a documented sample, a standard deviation, and a date, a web score is just a count. This site’s games are not normed batteries and must not be read as a clinical IQ, a school placement, or a medical finding.

Test Norming Basics →
People also search for:What Is Attention Control?IQ and IncomeVisuospatial vs VerbalWhat Is Cognitive Flexibility?Test Norming BasicsSocioeconomic Status and IQ
📅 Last updated: 2026-08-27 · ✔ Reviewed by the All-Lifes editorial team · About · Methodology
📚 Sources & references
← Back to the IQ Test