see.rEffect.tck {asbio} | R Documentation |

## Visualize random effects model

### Description

An experiment to ascertain the effect of two randomly selected brands of soil fertilizer
on wheat yield. In the upper figure two brands of fertilizer (1 and 2)
are randomly chosen from a population of potential choices. The mean yields produced by the
population of fertilizers `E(Y|A_i)`

are normally distributed. That is, it is possible to
select a factor level that will result in very small average yields, or one that will
result in large average yields, but it is more likely that a chosen factor level will
produce some intermediate average effect. We proceed with the experiment by assigning two
experimental units (two wheat fields) to each fertilizer. We assume that the yield of
fields is normally distributed for each fertilizer, and furthermore that the factor
levels are homoscedastic. We weigh our evidence against the H`_0`

of a non-zero population variance by estimating the
variability among factor levels. The more that yield varies with respect to nutrient treatments the more evidence we will have against H`_0`

.

### Usage

```
see.rEffect.tck()
```

### Author(s)

Ken Aho

*asbio*version 1.9-7 Index]