Calculating Mean and Standard Deviation in Sports Science
Understanding Mean Values
The mean is one of the most fundamental statistical measures we use in sports science. It helps us understand the "average" performance or measurement in our data set.
Calculating the Mean
The formula for calculating the mean is:
- Mean= sum of values / number of values
Let's say we're measuring vertical jump heights (cm) for five athletes: 42, 38, 45, 41, 39
Mean = (42 + 38 + 45 + 41 + 39) ÷ 5 = 41 cm
Understanding Standard Deviation
Standard deviation (SD) tells us how spread out our data is from the mean. It's crucial in sports science because it helps us understand the variability in performances or measurements.
What Standard Deviation Tell Us
- The mean gives us the central tendency
- The SD tells us how consistent or variable the performances are
A smaller SD indicates the values are clustered closer to the mean, while a larger SD indicates more spread-out values.
Don't forget that SD should always be reported with its original units (like cm, seconds, or kg). Many students leave off the units!
Normal Distribution
In sports science, many measurements follow a normal distribution, where:
- About 68% of values fall within ±1 SD of the mean
- About 95% fall within ±2 SD
- About 99.7% fall within ±3 SD
When working with performance data, always look at both the mean and SD together. A mean alone doesn't tell you about the consistency of performances!
