# Repeated

**Compares adjacent levels of an independent
variable.** The general matrix form is

```
mean (1/k 1/k 1/k ... 1/k 1/k)
df(1) ( 1 -1 0 ... 0 0)
df(2) ( 0 1 -1 ... 0 0)
. .
. .
df(k-1) ( 0 0 0 ... 1 -1)
```

where *k* is the number of categories
for the independent variable. For example, the repeated contrasts
for an independent variable with four categories are as follows:

```
(1/4 1/4 1/4 1/4)
( 1 -1 0 0)
( 0 1 -1 0)
( 0 0 1 -1)
```

These contrasts are useful in profile analysis and wherever difference scores are needed.