Range and Standard Deviation

Why should you add 1 for the range?

Its a mathematical correction that allows for the fact that raw scores are often rounded up or down when they're recorded within research.

What's an advantage for the range?

It's easy to calculate.

What's a disadvantage for the range?

It only takes into account the 2 most extreme values, and this may be unrepresentative of the data set as a whole

What is standard deviation?

A single value that tells us how far scores deviate the mean.

What happens if the standard deviation is larger?

The dispersion within a few of data is greater.

What does a large standard deviation suggest, if we're talking about a particular condition within the experiment?

Not all participants were affected by the IV in the same way because the data are quite widely spread and may be that there are a few of anomalous results.

What does a low standard deviation value reflect?

The data are tightly clustered around the mean, which might imply that all participants responded in a fairly similar way.

What does standard deviation include?

All values within the final calculation

What's a bad thing about standard deviation?

Like the mean, it can be distorted by a single extreme value.