# Neurofeedback – What is a Z Score?

Neurofeedback is an established, well-investigated treatment for conditions like ADHD and epilepsy. This type of EEG biofeedback allows clients to observe their brain wave patterns on a screen and get feedback when their waves are closer to normal.

A more recent protocol, z score neurofeedback (ZNFB), compares the participants’ eyes-open or eyes-closed QEEG assessments to normative databases. Z-score training only targets those QEEG parameters that deviate from the norm.

## What is a Z-Score?

A z-score is a number that represents how far a data point is from the mean. It is calculated by subtracting the average value from a raw score and then dividing by how much values typically vary (standard deviation).

To calculate a z-score, you will need to know the population mean and standard deviation of the sample that you are analyzing. You can find these numbers by using the formula: z = (x-m)/s, where x is your raw score, m is the population mean, and s is the population standard deviation.

Once you have your z-score, you can compare it to the normal distribution curve. If your z-score is positive, this means that your score was higher than the average score. If your z-score is negative, this means that your score was below the average score. In either case, this indicates that you performed better than the average test taker. It is important to note that just because your z-score is positive doesn’t mean that you scored well on a particular exam or test.

## How is a Z-Score created?

The formula for calculating a z-score is (data point – mean) / standard deviation. This is known as normalizing, and it is how raw data points are transformed into z-scores.

When a data point is compared to the population mean, it is placed on the curve of a normal distribution. A z-score can be positive or negative, and it indicates how far the data point is above or below the mean.

In order to find the z-score for a specific data point, you must first know the mean and standard deviation of the entire population. You then subtract the mean of your sample from the raw score and divide by the standard deviation of your population. You will then get the z-score for your particular sample point. The higher the z-score, the closer the data point is to the mean. A low z-score, on the other hand, means that your data point is below the mean.

## What is the goal of a Z-Score?

The goal of a z score is to indicate where your data point lies on the normal distribution curve. The higher the z score, the farther away from the mean your value is. This doesn’t necessarily mean it is good or bad; it just means that your data point is further from the average than most other values are.

To calculate a z score, first enter the mean, m, and standard deviation, s, into the formula. Then, divide your X-value by the population standard deviation and multiply by your s/m ratio. Finally, add the resulting number to your X-value.

The inverse normal distribution is often used to convert real-world data into a more statistically significant format. This allows researchers to compare results across different datasets and determine how unusual or extreme a particular value is. This can be helpful when analyzing data from tests or surveys that have thousands of possible outcomes and units. It can also help researchers avoid false positives by determining whether a data pattern is likely due to random chance.

## How does a Z-Score work?

A z-score measures how far a raw score (x) is from the population mean (m). The formula is (x – m) / (population standard deviation sd). To find a z-score for a particular value, you need to know the population mean m and the population standard deviation sd.

Once you have these values, you can use the z-score formula in Excel. Just enter the mean and standard deviation into the formula, and the z-score will appear in the box.

The z-score indicates where the data point falls on the standard normal distribution. If the z-score is negative, this means that the raw data point is below the mean. Positive z-scores indicate that the raw data point is above the mean. When you compare a z-score to the standard normal distribution, it can help you identify outliers in your data. Outliers are raw data points that are significantly above or below the mean. If you see a z-score of +/-3 or more, this means that the data point is an extreme outlier in the population.